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2,709 Posts
Discussion Starter · #1 ·
Edit on 7-16-17 - I removed some of the bad inline Photobucket links and attached the images directly to the thread. The attached images should be in the same order, but will be a little more difficult than the inline images. Also, there's a limit to the number of attached images (ten), so some images are missing. Post up in the thread if you want to see a missing image or if something isn't clear, and I'll add details/pictures as needed.

I thought I'd document progress on my 8.8 swap. Nothing revolutionary is going on here - I'm following in many other's footsteps. There's a bunch of great links to other threads in the Appendix - Part 9

The first 9 posts of this thread are:
Part 1: Introduction and Acquiring Parts (completed Aug 2013)

Part 2: Disassembly, Welding Tubes, Cutting and Painting (completed Sept 2013)

Part 3: Parking Brakes, Bearings, Seals, Reinstall Axles, Solid Diff Cover, Calipers and Rotors (completed Sept 2013)

Part 4: Tummy Tuck and MORE Shock Brackets (completed Oct 2013)

Part 5: Setup 8.8 in Jeep, Finish Weld Perches and Shock Mounts and Run Brake Lines (Completed Oct 2013)

Part 6: Exhaust System Mods, Final Axle Install and Parking Brake Cables (Completed Nov 2013)

Part 7: Rear Driveshaft (completed Oct 2013)

Part 8: Skid Plate Mods and Final Pictures (Completed Nov 2013)

Part 9: Conclusion, Future Plans, Appendix (Completed Nov 2013

Update on 11-20-2013:
I'm adding a couple of more projects, since they are related to increasing ground clearance.

Part 10: 1" Gas Tank Lift (Completed Nov 2013)

Part 11: TJ Rear Flares (originally planned for Dec 2012 as part of this build, then moved to this thread instead: StanF Rocker Guards and TJ Flares)

Part 12 BONUS - Added Detail on Parts Options for your 8.8 Swap: StanF Parts Detail
Part 1 - Introduction and Acquiring Parts

Reason for Swap:
My goal is to have a nice rig that I can drive to the trails and drive back (not trailer back!). In particular, I wanted a "bulletproof" rear end that would always get me home, and potentially accommodate larger tires in the future. (I'm on 32" tires at the moment)

Honestly, I would have preferred a Dana 44, since they were stock in some Jeeps (just not my YJ!). But Dana 44s are hard to find in my area and expensive. I chose the 8.8 because (in no particular order):
1) They are readily available in the gear ratio that I need (4.10)
2) Cost is reasonable
3) There's a wealth of information online about performing this swap
4) Swap parts and kits are readily available
5) Uses the same 5 on 4.5" Stud spacing as my Dana 35, so no wheel changes
6) Disc brake upgrade for free! (just choose the right Explorer as a donor 1995-2001)
7) Ground clearance is about the same as the Dana 35

I see three minor downsides:
1) The 8.8 is a little more narrow than the Dana 35 - about 5/8" on each side. I'm not concerned, but you could use wheel spacers ($$) to correct this if it bothers you.
2) I really hate putting a Ford part into my Jeep
3) The pumpkin is off-center a bit

My existing Dana 35 is a weak point, and adding a locker would make it even less reliable. A previous owner evidently had issues with my Dana 35 because of the marks on the carrier:

While I am doing the 8.8 swap, I am also doing several other "extras". They are things that won't be noticeable to the untrained eye, but that can improve the offroad capability:
- Tummy Tuck with a Barnes Flat Skid Plate. I am doing this for more ground clearance. It's included as part of the 8.8 swap, so I can get the pinion angle set right.
- MORE Shock Extensions - I'm installing these so that I can mount the shock brackets higher on the axle for more ground clearance and fewer snags
- Dynatrac U-bolt Flip Kit - for more ground clearance and fewer snags

Luckily, the Jeep isn't a DD, so I can take my time with all these mods.

Find an 8.8:
To the local pull-a-part junkyard, we go:

I found it was best to look at the door tag to figure out the axle ratio.

This is a sample image - not the one from my 8.8 donor

The "45" code equates to an open differential with 3.55 gears.

For those few Explorers without doors, I crawled under and looked at the tag on the pumpkin.

Here's a neat cheat sheet to take with you to the yard:

It took me three trips to get an axle...
The first trip (to a junkyard up north, 45 miles away) was a waste - they didn't have any 4.10 rear ends.
The second yard (80 miles south of the other yard!) had two of them. After screwing around with rusted bolts for way too long, we ran out of patience, and the 107 degree heat chased us away before we got one out of the Explorer. That Explorer wasn't from Texas, as it was way too rusty - every bolt was a serious PITA.
Finally a month later, I found this beauty with 4.10 LSD (the only one with in the yard).

I'm not thrilled with 180k miles, but it's not like I had a bunch of choices. It was a limited slip axle, which was fine. Since I have plans to install a locker, I wasn't real concerned if my 8.8 was limited slip (LSD) or open. It came out pretty easy - no rust at all on it. I don't think we even cracked open the PB Blaster.

The regular price for a rear end was $125, but they charged me a $25 core fee, and extra for the parking brake cable and calipers, and, of course, sales tax. At first, they tried to charge me for the rotors, but they weren't any good. I got a 1310 yolk out of an older Explorer, and it was included in the price.

Even though I wasn't planning to use them, I grabbed the U-bolts. Unfortunately, I didn't get the U-bolt plates. In hindsight, I wish I had gotten the plates too. Others have cutoff and used the Explorer shock mounts instead of buying new ones. It would be better to have them and not use them.

$200 later, it was sitting in my garage. It stayed there for about a month while I bought the other parts for the swap.

First, let me say that there are MANY companies that make individual 8.8 Swap Parts and complete kits. Some of the places are MORE (Mountain Off Road Enterprise), Ruff Stuff, East Coast Gear Supply, Barnes 4x4, etc. Look around and price the stuff that you need/want. I believe that all the kits will work, but some may be better suited to your build (or budget!) than others.

Since I was using Dynatrac's Ubolt Flip Kit, I didn't need U-bolts, so buying a complete kit didn't make sense. I would have just ended up spending more $$ on extra parts. So I pieced together my parts from several suppliers.

The cost of all this stuff adds up fast. I bought more than I needed to, and I wish I had more time to fab stuff myself. One note...I went with all new brake components - I just didn't want to take a chance on anything not being perfectly right. It added quite a bit to the cost, but it was worth it to me for peace of mind.

8.8 from Junkyard $200
1310 Yoke Adapter $0 (included with 8.8)
Solid Diff Cover $82 (
Parking Brake Cables $77 (East Coast Gear Supply) (edit on 11-6-2013 - beware of issues - see Part 6)
Brake Line Kit $67 (East Coast Gear Supply) (edit on 10-30-2013 - not recommended - see Part 5)
Parking Brake Shoes $20 (local auto parts store)
Parking Brake Hardware Kit $20 (local auto parts store)
Rotors x 2 $60 (local)
Mopar Leaf Spring Perches P4120074 $13 (JEGS - (edit on 10-30-2013 - not recommended - see Part 4)
Shock Mounts $22 (Barnes4x4
MORE Upper Shock Mount Extensions - $100 (
Dynatrac U Bolt Flip Kit - $215 (
Set of Calipers/Pads - $85 (Rock Auto)
Brake Fluid $5
Gear Oil $13
Vent Hose $5
Friction Modifier $5
Axle Seals and Bearing Kit $28 (eBay - great price!)
Disc Brake Align Kit $6 (Rock Auto) - these are the four little tracks that the disc pads ride on
Paint, Cutoff Wheels, Grinding Wheels, Rags, etc. - $30 or so
Rear Lift Shackles/Bushings - $70
Sell Dana 35, 4.10 Gears and Solid Cover - minus $300 est

I'm up to $1133 in parts, if I added right! :eek:
About $300 of this is directly related to the U-bolt flip and Upper Shock Mounts, so it's probably about $750 for the axle itself. That is offset by selling my Dana 35, so my direct upgrade cost for the 8.8 is about $500 and a bunch of labor!

I didn't add in the Tummy Tuck components or rear driveshaft, as they aren't directly related to the 8.8 swap.

East Coast Gear Supply has a bunch of 8.8 Swap Parts, as well as complete bolt-in axle assemblies, if you want to take the easy way out:

Edit on 2-7-2014:
A note on the 1310 Yoke Adapter...earlier Explorers with drum brakes - 1991 to 1994 came with 1310 driveshafts and yokes. The most cost-effective way to get this yoke is to take it off an older Explorer while you are at the junkyard pulling the axle out of the later Explorer. My local Pull-a-Part charges $7 for the yoke.

Edit on 2-7-2014:
A note on the Solid Diff Cover:
I find the Solid Diff Cover to be one of the best values. It's very heavy and beefy, and even comes with a tube of RTV. It's about $75-80 with shipping, which is about half what other similar covers cost. Highly recommended!

Here's a few pictures of all the new axle parts:

Next Step is Prepping the Axle


2,709 Posts
Discussion Starter · #2 ·
Part 2 - Disassembly, Welding Tubes, Cutting and Painting

Prep the Axle:
I moved the axle away from the wall, and proceeded to strip off the brakes, etc.

Everything came off very easily - nothing was tricky. I saved everything and took it off nicely. I don't believe that I will need to reuse any of it, but I'm not 100% sure. (And even if I can't use it, someone else might be able to use it.)

The driver's axle seal was leaking - there was oil in the rotor parking brake. I'll replace both the axle seals. (I'm not planning to replace the pinion seal until I install a locker)

Next up is welding the tubes. Started cleaning the tubes with a wire brush in my Harbor Freight angle grinder :shhh: (I purchased it for just one project, and it keeps running and running and running!)

I have some more cleaning of the weld line to do, then we'll start welding. It might be a while...if so, I'll start removing the old perches, cleaning, painting, etc.

Continued on 9-2-2013:
I was able to get out into the garage a few hours each day over this long weekend, and feel like I made some progress.

First, I spent some time last week buying a welder and associated equipment. It's great, but expensive. It'll pay for itself with all the projects that I have planned, as well as just the convenience of being able to do it in my garage on my own schedule.

I'm no welder (at least not yet!), but I did an adequate job on the tubes. I welded about 1", then switched to the other tube. Then rotated the axle and welded another 1" until I was completely done. The later welds were definitely better than the first welds. Honestly, I had to grind quite a bit and touch up a few places here and there. But it's not a critical weld.

Cutting off Perches and Brackets:
After welding, I started cutting off and grinding the perches and sway bar brackets. At this point, I was still using my Harbor Freight 4" angle grinder.

After 3 of the 4 brackets were off, I killed the Harbor Freight Grinder. I assume that it overheated. No great loss - I was glad it died. I replaced it with a very sweet Milwaukee 4.5" angle grinder from Home Depot. It is smooth and powerful and much much faster than the HF grinder. Highly recommended. As a side note, I used most of the 4" cutting wheels and grinding wheels that I bought from HF. They worked fine, and seemed to be a decent value for this application. I used up almost all of them, so I need to buy a few more 4.5" discs.

All brackets off, and on to grinding smooth:

My neighbor took this photo:

Everything ground smooth.

Hacking the Pumpkin:
There are a couple of other optional areas to clean up on the pumpkin. First, I cut off the guard tabs adjacent to the ABS sensor. Very soon, I will remove the sensor and replace it with a freeze plug from ECGS, then grind down that area flush. I hacked off the tabs in several passes to get close to the machined surface and reduce grinding. Others like to use this hole as an oil fill hole. I decided to just use the standard fill hole, and plug this up.

There's also some extra material where a bracket was attached. I went ahead and cut it off too. I cut less than my marked line. I finished the corner with a hacksaw. This extra material will likely not hurt or drag on anything, so there's not a great need to remove it.

Removing the Axles:
I didn't get pictures of this, as my hands were dirty. The process is pretty straightforward:
1) Remove cover
2) Remove cross pin retaining bolt (8mm wrench)
3) Remove cross pin
4) Push in axles and remove C-clips
5) Remove axle
BTW, gear oil stinks...

Removing the Parking Brakes:
My hands were still dirty, so no pictures...I also removed the parking brakes. Look at the link in Part 9 for a good post on the Parking Brake removal/replacement. I'm replacing all the shoes and hardware, but I kept all the removed parts for the time being.

At the end of the day, I was left with this:

Next up is cleaning and paint. Don't worry - I'll put the cover back on the pumpkin to keep everything clean in there.

I need to buy some new seals, and maybe some new bearings. I'm just not sure if new bearings are needed - comments?

Update on 9-4-2013:
I removed the Ford ABS sensor and installed a plug from East Coast Gear Supply. It was only $1.50, and seems like a pretty good solution. I put a little black RTV on it before tapping it home with a hammer. I don't have a specific picture, but I ground the extra casting material flush with the machined surface.

After quite a bit of cleaning, I started priming:

I know I'll have to grind off the paint at the weld locations and touch it up later. Others have done it differently. I may regret it later, but I don't think it's a big deal either way.

I'll finish up the painting on the pumpkin tubes, then prep and paint the axle flanges and disc brake bracket/shields. Then I'll start reassembling the brakes. I ordered new axle bearings and seals, and I'll install them after the parking brakes.


2,709 Posts
Discussion Starter · #3 ·
Part 3 - Parking Brakes, Bearings, Seals, Reinstall Axles, Solid Diff Cover, Calipers and Rotors

I decided not to repaint the caliper brackets and disc shield - they were in good shape, and I'm not trying to create a show Jeep. I just did some cleaning and put them back on.

I replaced the seals and bearings using loaner tools from Autozone. It saved me from buying about $150 of tools, as well as storing them somewhere. Here are the loaner tools that I used:
27129 Axle Bearing Removal Set
27119 Master Bearing Driver Set
27033 Slide Hammer
I'm giving the part numbers here because the guy at Autozone had a difficult time figuring out exactly what I needed. Sorry, but I didn't get a picture of them. You can also buy the tools almost anywhere, as well, as Harbor Freight :rolleyes:.

I'm not going to go into detail on the parking brakes, either, as I didn't get any good pictures. There is a link to a good writeup in the Appendix - Part 9. One thing that helped me with the brake pad retainers was to use a pair of long nose vice grips to help hold the pin.

Finished Parking Brakes:

Then the axles were installed...along with the c-clips, crosspin and retaining bolt.

The rotors were installed, and the parking brake star wheel was adjusted to give a nice fit on the rotors.

Then I lathered on some RTV and installed the Solid Differential cover:

Calipers went on easily:

I'm extremely happy to see all those boxes of parts installed on the axle. :cheers:
I'm not going to mess with the parking brake cables or brake lines until after the perches are tacked onto the axle.

Now I'm going to move over to the Tummy Tuck. I want to do the Tummy Tuck now, so I can accurately set the pinion angle.

The Tummy Tuck consists of:

1) Welding up a separate transmission crossmember
2) Moving the exhaust system out of the way
3) Installing an NP231 with an SYE (and clock ring, if necessary)
4) Installing a flat Barnes 4x4 Skid Plate

It should be a fun part of this project - I'm excited to be moving onto this next step. The only downside is that from this point on, the Jeep will be out of commission.


2,709 Posts
Discussion Starter · #4 ·
Part 4 - Tummy Tuck and MORE Shock Brackets

Tummy Tuck Introdution

A "Tummy Tuck" ("TT") is moving the transfer case and transmission further up between the frame rails to increase ground clearance. A perfectly flat skid secured right to the bottom of the frame is the gold standard for TTs, and is the goal for my build.

Here's a good picture of my T case from the rear. This shows a lot of details First, notice how the skid plate drops below the frame rails.
Second, notice the angle of the transfer case - it is clocked down about 10 degrees.
Third, notice all the space above the T case and transmission - this is the space needed to tuck everything up between the frame rails.
Fourth, notice the exhaust system on the passenger side - that's another area that will need to be addressed. I have a feeling that the exhaust will be the biggest PITA for me. I've done my research and have a good plan for all the other parts of the TT, but the exhaust is a big unknown at this point. I'm just going to wing it when I get there.

As a side note, a TT is the exact opposite of a Transfer Case Drop that is included with many 4" Lift Kits, which I wouldn't recommend for an offroad Jeep. For most people, I would consider a TC Drop a temporary fix until an SYE is installed.

Maybe I'm wrong, but TTs don't seem to be real common on YJs and are more common on TJs. There aren't a lot of good build threads on YJ TTs (my apologies in advance, if I have missed one of your excellent TT builds - if so, please post a link!).

- Increases ground clearance
- Typically involves adding a separate crossmember to support the transmission, so the skid plate can be removed without affecting the support of the drivetrain. Effectively, the skid plate is just a skid plate, and not the factory "skid plate/transmission support". It's nice when changing fluids, maintenance, repairs, etc.
- Generally, a stronger skid plate is installed, which will better protect the drivetrain

- Cost $$$$$ (see breakdown below)
- Requires lots of welding/fab
- Negatively affects driveline angles - SYE required
- Requires a body lift and motor mount lift (some will disagree about this - maybe it's not required, but it makes it much, much easier)
- It may involve some forming of the floorboard around the tunnel for increased clearance - especially at the yolk area (I am willing to do this)
- In extreme cases, it may involve cutting up your floorboard for clearance (I won't be doing this)

Honestly, there are a lot of reasons to just throw a larger lift on the Jeep (like the guy below! :D ), and forget all about the TT. Maybe I'll regret this route, but I hope not!

Here's a picture of a flat Barnes Skid Plate:

And a new stock YJ skid plate from Quadratec.

TT Costs:
These are the costs for my build - yours may vary.

General and for TT:
NP231J with SYE already installed - $250 (Craigslist)
1" Daystar Body Lift (BL) - $100 (eBay)
1" Motor Mount Lift (BBL) - $125 (Brown Dog)

TT Specific:
Flat 1/4" Skid Plate $120 (Barnes 4x4)
Crossmember Bushing Kit $44 (Barnes 4x4)
DOM Tubing for Crossmember $25 (local metal supply)
Clock Ring Transfer Case $75 (eBay - cutthroat 4x4) - I'm not 100% positive that I need this, but I believe it will make things easier)
EDIT on 11-7-2013: The Clock Ring made things much worse for me - I do not recommend it - read more below)
Exhaust Changes - my cost was about $75 - this includes $50 for a new TJ downpipe, new exhaust tip and other assorted pipe and adapters. $20-25 would be enough if you didn't make as many changes as I did.

Total is about $814 - it adds up fast, but I've been collecting parts for several months - this didn't happen overnight. I wanted an SYE, BL and MML for other reasons, so the extra cost to do the TT is about $339, which is reasonable. If the clock ring isn't used, then it could be less than $300.

In case you are wondering, I wanted the BL for more tire clearance. My old motor mounts were shot, so I went with the 1" MML for increased oil pan clearance. I installed both the BL and MML several months ago, and at that time, I knew that the TT would be a future project.

TT Process:

I'm starting with the crossmember. There are several different designs floating around - using channel, DOM tubing or square tubing. I kind of liked the kit at TMR Customs, and followed their general design. They sell a complete crossmember kit ($$), if you are looking for and easy way to make up the crossmember. I liked the design because it will be easy to set the lengths of the supports and tack everything together. The two smaller tubes slide into the larger center tube, so nothing has to be cut precisely to length.
TMR Customs Crossmember

I bought the DOM tubing locally (3' of 1.5" x .120 wall; 1' of 1.75" x .120 wall). I bought the bushing kit from Barnes 4x4, which contained all the pieces that would have been more difficult (not impossible) for me to fab up.
Barnes 4x4 Bushing Kit

I notched the ends of the 1.5" outer tubing with a grinder to get a good fit over the bushing tube. It was a little tedious, but didn't take long at all. The two outer tubes are probably too long right now - I'll shorten them later, if necessary. Using a flap wheel, I also removed the black coating from the bushing tubes in the area where I'll be welding.

I may need to angle the frame supports like the TMR design, but that will be easy with a cutoff wheel, if needed.

Next step is to get under the Jeep, support the drivetrain and take off the skid plate!

I purchased a clock ring to rotate the transfer case up and make it easier to do the TT...unfortunately, I got a clock down ring instead of a clock up ring. So, I'll be delayed several days while I swap it for the correct part. Here's a picture of the incorrect ring:

Nothing ever goes perfectly according to plan!
EDIT ON 11-7-2013:
The clock ring caused two issues. First, and most importantly, it caused the transfer case input gear to not seal properly on my AX5 rear output seal. It caused a steady stream of oil out of my AX5 after a short test drive. My solution will be to remove the clock ring and drill new mounting holes in the AX5 flange. The clock ring will serve as an expensive template for where to drill the holes. The clock ring was actually extremely helpful, because it would be difficult to drill the holes that overlap the recessed areas on the AX5 flange.
EDIT on 11-19-2013:
The clock ring wasn't the cause of the AX5 leak. My AX5 (not original) wants a longer input gear than my original NP231 has. I used RTV on the flange to seal it for the short term.

While you are here, you may as well replace the AX5 rear seal:

Unfortunately, I didn't take a picture of it, but the correct clock ring is installed (edit in November: and later removed!), and the transfer case is back in the Jeep.

To get completely flush with the frame rails, I had to cut out a portion of a support channel in the tub with an angle grinder.

I also got the crossmember supports welded in. My welds aren't great, but they are functional - it's difficult to weld underneath the Jeep. A few notes:
1) The two frame rails aren't parallel where the crossmember sits, so the crossmember supports had to be cut to different lengths. The front support was about 1/2" shorter than the rear support.
2) My transmission wasn't sitting perfectly level with the frame rails - it tilts a little to the passenger side. I had to account for that when I welded the transmission bracket to the crossmember.
3) My transmission also isn't centered between the frame rails - it's oriented about an inch over to the passenger side. I didn't try to correct it. Again, I just accounted for it when I tacked the transmission bracket to the crossmember.
4) The various angles at the transmission caused me to first weld in the crossmember supports and crossmember, and then, as a second step, add the transmission support to the crossmember.
5) I used the nuts for the skid plate as a reference on the two frame rails when I welded in the supports to get the crossmember perpendicular to the frame rails.
6) I tacked everything in place, and then disassembled and finish welded all the pieces. When I went to reinstall the crossmember, it was about 1/16 too short for the frame rails. :brickwall I ended up drilling out the mounting holes on the passenger side to give it a little more tolerance.
7) The crossmember sits flush with the bottom of the frame rails. The skid plate nuts sit lower than the frame about 1/8", so, worst case, I should have about 1/8" of clearance between the crossmember and skid plate. (to be confirmed, of course!)
8) I will likely have to drill large clearance holes in the skid plate for the two bolt heads that hold the transmission to the crossmember.

Update on 10-22-2013:
The crossmember is all welded and painted:
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And installed:
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I'm completely up between the frame rails:
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Next step...get the MORE shock mounts installed, and get the 8.8 under the Jeep, so I can measure for the rear driveshaft.

To be continued...

MORE Shock Brackets
MORE Shock Relocation Brackets move the upper shock mount up a few inches. This is useful for either using longer shocks, or, as in my case, so that the shock mount can be rotated up on the axle to provide more clearance and fewer snags.

This is the best explanation of why I want to install the MORE upper shock relocation brackets:
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that picture is from this thread:
Broken Shock Bracket

Updated on 10-27-2013:
The MORE brackets are pretty easy to install - you drill a 1/2" hole and then bolt the brackets onto the existing shock stud. No welding is required, but the hole needs to be pretty accurate, which isn't very easy.

Holes Drilled:
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The brackets come unpainted, so you will want to spray them before install:
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Bolted in:
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The shock mounts give you 2" of extra length, so you can either fit longer shocks for more flex, or raise your lower shock mounts up 2" with the same length shocks. I'm keeping the same shocks and will raise my lower mounts 2" when I install the 8.8. Details/Pictures will be in the next section.

The new shock angle causes interference with the fuel filter skid plate on the driver's side and the muffler heat shield on the passenger side. I'll detail those changes in Part 7.


2,709 Posts
Discussion Starter · #5 ·
Part 5 - Setup 8.8 in Jeep, Finish Weld Perches and Shock Mounts and Run Brake Lines

Update on 10-27-2013:
Out with the old...

In with the new...

Other changes:
Dynatrac U Bolt Flip Kit:

5" Long Lift Shackle - this will make up for the 1/2" loss of lift height from the larger tube, perches, etc. These have to be installed before you set the pinion angle!

Of course, part of this process was laying out the new perch locations, and removing the paint from the area to be welded.

Everything was bolted into the Jeep, tires were installed, and the perches and shock mounts were tacked in place. I took great care in setting the pinion angle, so I hope it's right! My driveshaft length is 19.75", and my driveshaft angle at ride height is right about 20 degrees.

One slightly weird thing is that the hole in the perch is much larger than the standard Jeep leaf spring bolt head - I need to figure this one out. The hole in the new Mopar perch is .670". The head of the leaf spring bolt is .490". The perch hole in the Dana 35 is about .520".

Update on 10-29-2013:
I fixed the perch hole by welding in a 3/16" thick plug. I used a hole saw to drill out two plugs from some 3/16" steel that matched the perch thickness. The plugs were too large at about .730" diameter, so I put them in a vise and carefully took them down to about .670". Then I welded them in, ground them flush, and drilled the hole to a sloppy 1/2". It sounds complicated, but it was actually very quick to do. That being said, if I had it to do over again, I would use a different set of perches.

First plug set in place, and the second plug sitting on top of the perch:

After welding and grinding flush (and before drilling out the hole to a sloppy 1/2"):

I finished welding the perches and shock mounts and got a coat of primer and semi-gloss black on them:

I got confirmation that Tom Woods shortened and shipped out the driveshaft today, and it is expected on Friday via Brown Santa. I can't recommend Tom Woods highly enough - they are really great and know their stuff.

Brake Lines:
I bought the ECGS brake line kit for the 8.8 which includes a couple of stock Jeep soft lines and two hard lines in different lengths (16" and 34"). The ECGS kit doesn't come with any instructions or pictures - they leave it to you to figure out what to do. A big "thumbs down" :thumbdown: :thumbdown: :thumbdown: :thumbdown: to ECGS for lack of any info at all. Their kit isn't cheap at $67 + shipping, and it just includes parts available from any good auto parts store. I had higher expectations for ECGS, and was let down with this kit.

Luckily, this forum is great! In particular, "Feetwet" has a great 8.8 build thread, and did a great job on his brake lines Feetwet 8.8 Brake Lines. After seeing what he did, I'm considering copying what he did. The only difference is that I may even re-use the 8.8 hard brake line. This could be very cost-effective for budget builds. Just don't cut the "T" line when you are removing the axle like I did :(

Here's another similar brake line technique from JEDI. He is SOA, but it's still pretty similar to Feetwet. Jedi 8.8 Swap

After looking at everything, I decided to use most of the ECGS parts. I really didn't want to spend more $ on new Explorer brake lines, and I already had the ECGS parts. First, I had to make proper brackets to replace the POS bracket included with their kit.

And welded them above the perches:

Then I bent the 34" line as shown. I used the factory 8.8 brake line clip, and also the factory center clip on the pumpkin.

The end of the 34" line determined where the stud was welded to the tube for the "T" Line. The stud (just a standard 3/8-24 bolt and nylon locknut) was included with the ECGS kit.

On the driver's side, I thought that the included ECGS 16" hard line was too long, so I bought a 12" line at the local parts store for $5. Again, I used the factory brake line clip on the driver's side. I am going to replace the 12" driver's side hard line, as I got one of the bends too tight. Also, I should note that I rotated the flex lines up when I torqued everything down - they aren't hanging down low as shown in the photo.

Bottom line...I don't recommend the ECGS kit at all. Use the Feetwet/Jedi technique.

Other miscellaneous info...
Banjo bolts were re-used from the old calipers with new copper washers that were included with the new calipers. They were torqued to 23 ft-lbs.

Good link for install of the ECGS Kit (but on a TJ):


2,709 Posts
Discussion Starter · #6 ·
Part 6 - Exhaust System Mods, Final Axle Install and Parking Brake Cables

Exhaust Mods
The exhaust system needed to be modified due to the crossmember. I took the opportunity to do a couple of other mods, as well. I wish I had some extra cash to just replace everything. But my existing system is functional, and will work with some adjustments. I think the exhaust changes will be easier to do before the axle is installed.

Exhaust Changes:
1) The CAT normally sits right where the crossmember sits, so it has to move up and rearward. The muffler will stay in the same place.
2) Replace YJ Downpipe with TJ Downpipe
The TJ downpipe wraps forward around the oil pan, which is in a much better location. It's much better protected and less likely to get hit when wheeling. I also had an issue with my front driveshaft rubbing on my old YJ downpipe, and the TJ downpipe completely solves that issue.
3) A previous owner installed a straight chrome exhaust tip that was prone to damage. I also get some fume blowing back into the Jeep, so I want to use a turned down exhaust tip.

Old Exhaust:

The chrome tip had to go! It saw some trail damage!

Everything in front of the CAT is new. I shortened the distance from the CAT to the muffler by 2-3" to move the CAT out of the crossmember. There aren't any butt welds - everything was sleeved. Even with that, I managed to blow three holes into the pipes :eek:
All tacked up:

The pipe had to move up and over the crossmember, so I used two tail pipes with a connector in between to get the spacing right.

After final welding:

I also added a front exhaust hanger. I welded a piece of 3/16 plate to the frame, and then bolted the hanger to it.
I'll try to get a picture soon

Final Axle Install
Update on 11-6-2013
Since the axle was already installed when the perches/shock brackets were tacked on, the final axle install is quick and easy. It's just a matter of:
1) Sliding the axle into place and lifting it on a jack
2) Lift the springs and install bolts in shackles
3) Set the axle down on the leaf spring locating bolt
4) Install U-bolts and snug down, don't torque
5) Install shocks
6) Install brake line
7) Attach new vent hose (I don't think I mentioned this before, but I ran a new vent hose)
8) Install driveshafts (could be done later, but I did it now while the Jeep was a little higher)
9) Install wheels
10) Lower Jeep down onto wheels
11) Final torque on U-bolts and shackles (and repeat again after a few hundred miles)
12) Add gear oil to the 8.8 (if not previously done)
13) Bleed brakes

Here's a shot showing my rear clearance:

Parking Brake Cables
I purchased a Parking Brake cable kit from ECGS for about $77. It includes two new cables (driver and passenger side) and a few clamps, which I didn't use.

Several others have purchased this same kit, and have had issues with the two cables being the incorrect length. Here's a good thread on the problem:

Basically, the two cables have to be a matched length to work properly with the Jeep brake bracket. Unfortunately, ECGS is sending out parts that don't work. This problem also affected me:

It's really unfortunate that ECGS is sending out incorrect or bad parts. For $77, I expected more.

Test Drive
I got everything done and did a short test drive on 11-6-2013. I only went about a block. The 8.8 was great - no issues there. The exhaust system was also great - no leaks or issues. However, I did find some other things:

1) I had a massive oil leak out of the rear of the AX5. I assume it's because the 3/8" clock ring is keeping the seal from working properly. I'm going to pull out the clock ring and drill the AX15 flange.
EDIT on 11-19-2013: The oil leak was caused because my AX5 isn't original to my Jeep - a PO swapped it out. This particular AX5 wants a longer NP231 input gear. My input gear is proper for a 1995, but it didn't even reach the seal. I sealed the flange with RTV for the short term. Longer term, I will probably swap in a 4.0L and AX15, and solve this problem at the same time.

2) I didn't have enough adjustment in the NP231 shifter rod - this is also due to the 3/8" clock ring. Removing the clock ring will also fix this. (Edit on 11-9-2013: I was wrong in my original diagnosis - the shifter was working fine. The problem was a broken 4wd vacuum switch on the NP231. It caused the "4WD" light to turn on, and caused the CAD (central axle disconnect) to engage, so it felt like 4x4 with my front locker).

3) Unrelated to my recent work, I noticed a small drip of gas coming from the driver's side of the gas tank lines where an old, worn soft line connected to a hard line. I'll have to drop the tank and replace all the rubber lines. I'll do the 15 to 20 gallon mod and a 1" Gas Tank Lift at the same time.

4) Also unrelated...I noticed that my front axle seals are also leaking. I'll have to tear into those soon.


2,709 Posts
Discussion Starter · #7 ·
Part 7 - Driveshaft and Tub Mods

Rear Driveshaft:
To make things move faster during the build, I did some of the preliminary driveshaft work out of order. I spent a couple of days in mid-September cleaning and rebuilding a front XJ CV driveshaft. It will be shortened and balanced and used as my rear driveshaft.

Driveshaft Introduction:
I had done some reading in the forum about using an XJ front driveshaft as an inexpensive rear YJ driveshaft. It sounded like a great way to save a little money, and a fun little project. The reality is that it didn't save any money at all, and it was a lot more work than a new one. However, it was probably still worth on.

Here's the XJ Driveshaft:

My costs total up to about $265, which is ridiculous, I know. You can buy a new Tatton driveshaft for less.
Driveshaft $35
3 Spicer Greasable U Joints $70 (Northern Drivetrain)
Spicer Centering Ball Kit $55 (eBay)
Shorten/Balance $105 ($90 to Tom Woods + shipping up to him)

I may have been able to get the Spicer components a little cheaper. I chose greaseable U-joints, so I can grease them if I get into any mud or water.

Why am I glad that I went this direction even though it didn't save any money? First, it'll be good to have the experience of rebuilding the driveshaft on the bench in case I ever have to do any driveshaft work on the trail. Second, I learned a lot about the different Spicer U-joints that are available (greaseable or not; different zerk locations; etc). So, in the end, I think my education was worth a few dollars more.

Driveshaft Shortening:
I went to two local driveshaft houses - the only two in town, I think. One wanted $120 for shortening and balance. The other one wanted $130. To be honest with you, I didn't get a good confident feeling from talking to either shop. I called Tom Woods - got a great, knowledgeable person on the phone. They wanted $80 + $10 ship/pack. Tattons wanted $75 + shipping. I decided to go ahead and ship it to Tom Woods - I think they will give me better advice and support than my local shops. As soon as I get the driveshaft measurement, I'll forward it to Tom Woods. I should have the driveshaft back a week or so after that.

Would an XJ driveshaft ever save money?
I can think of a few instances. First, if the U-joints and Center ball are good, then you can save a big chunk of change. If you only do slow crawling, and don't care much about balancing, then you could just pay for the cut and weld (no balance). Or maybe you have a less expensive local shop available. I've even read of people cutting and welding it themselves for the ultimate low price. None of these situations applied to me. I'm on the highway quite often, and wouldn't attempt to shorten it myself.

Disassembly and Paint:
My DeWalt impact driver and a ball joint tool made for VERY quick and easy U-joint removal. Highly recommended! So much easier than a hammer and sockets. (And yes, I take both of these tools out on the trail with me along with spare U-joints and straps.)

Then I cleaned up the grease and rust; masked off the important machined cup areas and rattle-canned it. (Yes, I'll have to touchup the shortened/welded section later). I did this to all three pieces - the shaft; the CV joint and the yolk.

One note about cleaning - the U-joint caps are a tight, press fit. Don't sand me or remove any metal. I carefully used a soft brass brush to clean out the snap ring groove. Otherwise, I left those surfaces alone.

Also, I was careful to mask off any machined surfaces on the yolk.

Here's a great link with details on rebuilding a TJ CV joint. Everything applies to the XJ driveshaft that I'm working on.
Stu's CV Joint Repair

Helpful Hint: There's a little washer in each cup of the U-joint. When you pull the cup off for installation, sometimes the washer stays in the cup and sometimes it sticks on the end of the joint. Be sure that every cup has only one washer - it would be easy to get two washers in one joint, and no washers in another, if you don't pay close attention during reassembly.

First end done:

CV Joint:

You can see the flush zerk fitting on the centering ball if you look carefully. All three zerks are on the same side, which is nice.

Reassembly completed and ready to be shortened (Sept 11, 2013):

Shortened Driveshaft and Paint Touchup
Update on Oct 27, 2013 - My driveshaft length at ride height was 19.75" and was emailed to Tom Woods. It was shortened and shipped out the next day. Total cost was $95 for shortening, balance and shipping. Awesome customer service - I can't recommend Tom Woods highly enough.

Tub Mod for Driveshaft Clearance
The double cardon joint didn't have enough clearance after the tummy tuck, so I had to "massage" the tub to gain some clearance. You can't really see what I did very well, but it is right in this area above the DC joint:


2,709 Posts
Discussion Starter · #8 ·
Part 8 - Skid Plate Mods and Final Pictures

Skid Plate Mods:

1) The Skid Plate from Barnes 4x4 worked great. Highly recommended.

2) I had to cutout the bent flange of the skid plate for the exhaust pipe and CAT; front DS; AX5; and Parking Brake. I was shooting for at least 1/2" of clearance in all the cuts. I may have gotten more than that on some of them. I also cut a couple of holes in the middle of the plate, so I'd have a little more clearance from the bolt heads that secure the crossmember to the transmission.

3) At some point in the future, I will likely weld some internal ribs to reinforce skid plate.

4) The bolt heads might also get hung up - I may weld on some skid pads to help obstacles slide over them.

The skid plate mods are best shown in pictures. There's a bunch of them below:

Parking Brake Bracket Clearance:

CAT Clearance:

AX5 Clearance:

Front DS Clearance:

Exhaust Pipe Clearance:


Final Install:

Final Pictures:
Front View showing driveshaft angle - looks pretty good, and no vibes :)

While the gas tank was out, I got some good pictures:

Won't be snag free, but should snag less:



2,709 Posts
Discussion Starter · #9 ·
Part 9 - Conclusion, Future Plans and Appendix

What went right...
What would I do differently...

What went right:
Overall, I'm very pleased with the outcome. I had a pretty solid plan, and didn't have to make many changes along the way. I had a few setbacks along the way, but all the different pieces came together for a good final product. I would highly recommend the 8.8 swap to anyone who needs a stronger axle.

The most fun part of this project was building up the 8.8. It was a great deal of fun. (Everything else, pretty much sucked, as I was on my back under my Jeep the rest of the time.)

While not completely necessary, having a nice welder (Hobart 210MVP) and angle grinder (Milwaukee) made this project much, much more enjoyable.

I haven't gone offroad yet, but I'm very pleased with the extra clearance from the MORE shock extensions and Dynatrac U Bolt Flip. These were relatively expensive options, but I think it's money well-spent.

What would I do differently...

First, I had unreasonable time estimates - it took me a couple of months to do this. Luckily, my Jeep isn't my daily driver. I missed some of the best topless weather while my Jeep was up on blocks. The amount of time I spent doing this makes me concerned about how long it will take for me to do my future 4.0L/AX15 swap.

Second, I wish I had planned more help along the way. I kind of did things ad hoc when I had a couple of hours here and there. I wish I had invited some friends over to help during the process and spend a Saturday knocking a bunch of stuff off the "To Do" list.

Third, I wish that I had the money to install a locker while I was building up the axle. It would have been much easier to set everything up with the other axle work. Especially with it out of the vehicle.

Finally, with 20/20 hindsight, I would not have purchased:
1) A clock ring. It's better to just drill holes in the transmission flange for a Tummy Tuck (although it was a nice template!).
2) The ECGS parking brake cables. They worked, but don't really fit correctly. It would have been much cheaper to reuse the Explorer cables, and only a tad more difficult.
3) The ECGS brake line kit. They worked, but reusing the Explorer lines would work perfectly and be free.
I could have saved about $200 on the Tummy Tuck and 8.8 Swap if I hadn't purchased these items.

Future Plans:

Gas Tank Lift - 1"
I'm actually in the process of doing this now (Nov 2013). It'll gain me another 1" of ground clearance in a vulnerable area. I did the 15 to 20 gallon mod, and will replace all the rubber fuel lines at the same time.

Install Rear TJ Flares
I have a set already - I just need to do some cutting and drilling to get them installed. It'll be fun to tackle a project that doesn't involve laying on my back underneath the Jeep! I should have them installed sometime in Dec 2013.

Rear Locker
A rear locker is very high on the wish list. At some point, it will bubble to the top of the list - probably sometime in 2014. As far as locker options go, I wish I could afford an ARB. I may even spring for one after doing more research. At this point, I'm leaning towards the Detroit. I want something better than a lunchbox locker, but something less expensive than an ARB. The Detroit fits pretty nicely right between those options.

Super 8.8 Kit:
This kit does several things...eliminates the c-clips; larger outer bearing and seal; increases width (~.96" to each side); adds chromoly shafts. That being said, for my purposes at the moment, I think my stock 8.8 will be fine. I'll consider this if I ever go up substantially in tire size (35" or larger).


There's a wealth of knowledge in this forum and all over the web. Here are a few helpful links that I used in planning/performing this project:

General 8.8 Info:
Good General Information on 8.8s, Specs, etc
Swapping an 8.8 into a Ranger pickup (interesting for background, as the Jeep process is almost the same)
8.8 info from (not real useful, but some good background info)
Junkyard Cheat Sheet (thanks to the original source - I found it somewhere)

8.8 Builds/Info:
Jeep Jedi 8.8 Build
Lots of Discussion on this Build Thread
Good 8.8 Build with Lots of Pictures
Good build with costs from Denis Baldwin (he painted his 8.8 green!)
Powertrax Lunchbox Locker installed into an 8.8
Very Similar to My Build with Ubolt Flip, etc (a little light on details, unfortunately)
Another build with good pictures and text
8.8 Locker Recommendations

Tummy Tuck:
95YamJam TT
Good pictures of transmission crossmember installed

Parking Brake Cable Solution (I didn't use this technique, but it's a clever, cheap solution)
Replace 8.8 Parking Brake Shoes/
Good Link on Setting up the ECGS Brake Line Kit

What is a CV Driveshaft and Why Do I Want One? (Excellent Thread!)
Stu Offroad CV Driveshaft Rebuild

Gas Tank Lift:
Good Build and Details
Small Amount of Info and a few pictures

East Coast Gear Supply - lots of 8.8 swap parts
Ruff Stuff Swap Kits
Barnes4wd Swap Kits
MORE Swap Kits
Very complete swap Kit from (too expensive, I think)
Pegasus Auto Racing - Good Selection of Banjo Bolts
Tom Wood's Driveshafts
more links to come...

5,022 Posts
Looks like you have a good direction and plan ! Can I suggest an alteration ???? :)

I would return/sell off the mopar perches. Get some beefier 3" "adjustable" perches and move the axle back 1.5 inches. It's an easy "stretch" for minimal cost. I'll be honest saying I don't know if they work with the ubolt flip kit...but it's worth looking into. It's also as good a time as any since you mentioned TJ flare install and subsequent cutting. Cheers to the upgrade sir and happy grinding !

Sent from my iPad using JeepForum

1,322 Posts
Finally, a salvage yard that's smart enough to set the vehicles down on rims to keep the rotors out of the dirt. Its so annoying to to see a perfectly good set of axles dropped in the dirt, backing plates all bent to hell with mud all over the rotors and lug nuts. Then again, on a positive note, my local yard sells 8.8s for $125 with EVERYTHING attached to the rearend....track bars, shocks, springs, U-bolts, cables, etc.

Looks good so far!

Unfortunately, I didn't get the U-bolt plates.
I'm pretty sure I have an extra set of Explorer U-bolt plates, let me know if you need a set. I'm sure I can get them in a flat rate box, so just cover shipping and they're yours.

I went with all new brake components - I just didn't want to take a chance on anything not being perfectly right
I don't blame you for being careful, but I have done a few 8.8s and have yet to find a set of calipers that were bad from the salvage yard (knock on wood). Sure, you may have to replace the pads, but brake pads are inexpensive. Just an FYI, but while you're at it, now would be a good time to go ahead and replace your E-brake pads. Its considerably easier with the axle out of the Jeep!

Here's a thread I did on mine a couple years back:

2,709 Posts
Discussion Starter · #13 ·
Looks like you have a good direction and plan ! Can I suggest an alteration ???? :)

I would return/sell off the mopar perches. Get some beefier 3" "adjustable" perches and move the axle back 1.5 inches. It's an easy "stretch" for minimal cost. I'll be honest saying I don't know if they work with the ubolt flip kit...but it's worth looking into. It's also as good a time as any since you mentioned TJ flare install and subsequent cutting. Cheers to the upgrade sir and happy grinding !

Sent from my iPad using JeepForum
Thanks for the suggestion - that's one of the reasons why I started this thread. Moving it back is an interesting idea, for sure. I'm just not sure that I have room - here's a picture of my Dana 35.

I'm planning to raise the gas tank 1" - I did a 1" body lift a while ago, and just haven't gotten to the gas tank lift yet. But I don't think that'll help. I'm not a big JK fan, but I do like how their gas tank is tucked up high.

2,709 Posts
Discussion Starter · #14 ·

I'm pretty sure I have an extra set of Explorer U-bolt plates, let me know if you need a set. I'm sure I can get them in a flat rate box, so just cover shipping and they're yours.

I don't blame you for being careful, but I have done a few 8.8s and have yet to find a set of calipers that were bad from the salvage yard (knock on wood). Sure, you may have to replace the pads, but brake pads are inexpensive. Just an FYI, but while you're at it, now would be a good time to go ahead and replace your E-brake pads. Its considerably easier with the axle out of the Jeep!

Here's a thread I did on mine a couple years back:
Thanks for the link to the parking brake rebuild - that'll come in VERY handy! :cheers:

I think you're right about the calipers being good - I struggled with spending another $85 on them. To be honest with you, I'm lazy and didn't want to have to mess with the rear brakes again for quite a while (if ever!). I would rather spend my time doing other things to my swapping in this 4.0L :2thumbsup:


3,911 Posts
I bought this rig a couple of years ago and stopped payment on the check after I found out what a POS this rig was. The seller actually placed a hunk of metal in the rear end so it would blow on me as soon as I got up to speed. My guess was so that I would not notice that it was already blown. He sold me a rig with lockers I guess he did not expect me to replace fluids before I ran it. The lucky part for me is that I trailered it home. Come to find out both the front and rear end were bad. The tranny was bad too. I told him I would keep it for a lower price but I guess he wanted to screw someone badly so I gave it back. I was lucky I gave him a check! Basically the only things good on the rig were the body, frame, and wheels.


221 Posts
I wanted to stretch mine too. Tank issues. I decided to wait to stretch when I do a fuel cell. Then its on! Love my 8.8 though. I have quite a few posi black marks from my 36's from burn outs "testing" the LSD. Lol

417 Posts
I too was going to stretch when I installed my 8.8 but I figured if I was going to do it I'd make it worth while 5"vs 1.5". So I decided to wait
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