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The Comprehensive BDS/FatBob's 2" Lift Thread

265K views 631 replies 122 participants last post by  WolfPlayer 
#1 · (Edited)
Hello All!

I had some extra Xmas money and decided to go with a lift. I chose the 2" BDS springs from FatBob's Garage and paired the springs with Bilstein 5100 Shocks. While this is a pretty expensive way to go for "just a 2" lift", I am very pleased with the results. I will post everything I know here in one thread in hopes it will answer a lot of questions that we see on a daily basis here in the forum. I didn't photograph EVERY step, so some of the pictures are out of order (showing new parts where I describe removal).

The Springs
I picked up a set of "spring only" BDS lift kits from FatBob's Garage. The link to the product is here.

I chose to do a spring lift over a budget boost for several reasons.
1)The original Upcountry springs had sagged as much as 1-3/8" in front. Adding a budget boost on top of worn parts would only give me 5/8" lift over stock.
2)By nature, any sagging springs have also lost some of their original spring rate, making the truck handle poorly. The BDS springs have a higher spring rate than stock, making the truck handle better, despite having a higher center of gravity.
3)When wheeling, occasionally people report having a spring or spacer fall out while flexing. I tend to wheel with the sway bar disconnected, so this might have been an issue for me.
4)With no spacer inserted, they have greater available travel without binding.
5)They have a no-questions-asked lifetime guarantee.

There are three ways to make a lift spring. You can either keep the rate the same and make the spring longer, you can keep the length the same, but increase the rate, or you can use a combination of these techniques. BDS springs are only marginally longer than stock. In fact, they may be the same length as stock, but since mine had sagged their free length was not correct. The rears are obviously a little longer than stock, have an extra coil in them, and have significantly higher rate.

Front Springs


Rear Springs


I estimated spring rates of the stock springs as well as the BDS springs using diameter, number of coils, and wire diameter. Spring Steel is almost universal in composition (for automotive applications), so we can compare them directly. These are estimates based on wire diameter, number of active coils, and diameter of the spring.

Stock Front: 161 lbs/inch
BDS Front: 264 lbs/inch (64% stiffer)
Stock Rear: 217 lbs/inch
BDS Rear: 297 lbs/inch (37% stiffer)

[edit] BDS has commented on this thread that both front and rear springs are actually 240 lbs/inch. I am leaving my estimates up there because the comparison vs. stock is still accurate (the same error was made on both calculations so the percentage will still be VERY close).

Spring Isolators
This section is a new addition. My lift wasn't quite as high as I wanted and I had inconsistent lift height all around. After seeing what new isolators looked like, I was certain that mine had really collapsed. The results are perfect. The conclusion I can make: collapsed spring isolators another real source of WJ sagging. Upper isolators are not as much the problem. My uppers were distorted but not totally junk. The lowers were really quite collapsed.

Here's the part numbers you need:

Upper Front: Mopar: 52088 257AB, Moog: K160040, Raybestos Professional: 5771-704
Lower Front: Mopar: 5208 8401, Moog: K160041, Raybestos Professional: 5771-705
Upper Rear: Mopar: 5208 8346, Moog: K160061, Raybestos Professional: 5771-716
Lower Rear: Mopar: 52088 402AB, Moog: K160042, Raybestos Professional: 5771-706

Here are some pics illustrating the collapsed old isolators and the new ones. I didn't post the upper pics because I am limited to 20 pics per post. They are on Page 3.

Lower Front


Lower Rear


I went with the Raybestos Professional line over the Moog due to warranty, price, pictures, and reputation. The total cost for spring isolators was right around $100 for all 8 from RockAuto If you are looking to save some coin, just get the lower ones. They are the most important and were far more deformed. I REALLY recommend it so you don't have to do this job twice.

As a side benefit, the level of road noise is also greatly reduced and pothole impacts are much softer. Again, I really recommend replacing these, even if you are just getting a budget boost. You will see better results from any lift or even no lift at all - this will put you back to stock height.

The Shocks
I got Bilstein 5100s from Kolak here on the forum. He gave me a price that could not be beat as well as a free shipping promotional offer. This beat out Summit Racing by about $40, which is pretty significant. In addition, I got to support a great forum vendor!

Bilstein's 5100-series are high-pressure-gas-charged monotube shocks specifically valved for lifted applications. More info to be found here. I have used their Sport and HD-series shocks in the past and have always been happy. In addition, they have a lifetime guarantee "as long as it has not been used off-road".

If you purchase Bilstein shocks, you will need to provide some additional hardware. The OEM front shocks have studs welded into the bar pins where the mount to the axle. The Bilsteins just have holes. I tried to remove the studs but it was apparent after several heavy hammer blows that they were not pressed in (like I thought) but actually tacked in place.

Stock


Bilstein


The hardware you will need is 4 5/16-18 x 1-1/4" bolts Grade 5, 8 small 5/16" washers (grade 8), and 4 5/16" Grade 8 nylock nuts. All of these were available from Lowe's. I used Grade 5 bolts because the Grade 8 were not available in the right length, and honestly they will not be under that much strain anyway. The Bilstein shocks come with the appropriate bushings and hardware for the body-mount side, so no worries there.

The Install
The BDS Springs came with a 1-page instruction sheet which I glanced over for pointers, then I dove right in.

Front Axle

1)Loosen Lug Nuts. I discovered that the tire shop put them on "OMG TIGHT".

2)Pop hood and loosen top shock nuts. This is much easier when the rig is still on the ground. One the driver's side, there is a vent hose on a little plastic clip which attaches to the top of the shock. It is stubborn. The vent hose disconnects easily and then the plastic clip can be threaded off.

The offender


Removed


The nut on top is a 15mm and you will need a deep socket to remove it. I put a few drops of MultiOil (my new favorite penetrant) and zapped it off with a 12" extension and an 18v Impact Driver (not an Impact Wrench). This is my favorite tool and many suspension jobs would have been much harder without it. The passenger side is easily accessed. Use the same socket and extension. Pull up the small rubber bushing and washer from the top of the shock.

Passenger Side


3)Jack up vehicle. Be sure to jack in a location that allows you access to the frame rails because you will need to put jack stands there to support the body. Go as high as you can. I recommend at least a 3-ton set of jackstands, although I use a 4-ton usually.

4)Remove wheels/tires from vehicle. With the shocks already disconnected, the axle can droop MUCH more than normal. You may have to jack the body as high as possible, then support the axle with a jack to remove the wheels.

At this point your axle will look like this


Note that the shock is dangling and the spring has already unseated itself from the upper seat.

5)Remove shocks from the vehicle. This is just 2 13mm nuts on the bottom of the axle. Impact driver takes em off in a hurry. The shock lifts right out with no real drama. Throw directly in garbage.

Shocks removed


6)Remove sway bar end links. This will allow more axle droop. The BDS instructions said to also remove the track bar. I did not find this necessary. It's a lot more work and you shouldn't have to do it. The bolt is a 15mm head and the nut is an 18mm head. Due to torsion on the bar, there may be some load on the bolts. You might need to drive them out from the backside or jack a little on the axle to release the preload. You don't need to completely remove the end links, just unbolt from the axle. This gives you more travel if you need it.

7)With your dominant hand, grab the top of the spring and push down/pull out. It is loose enough at this point it pretty much just pops out. If you don't have enough room, then push down on the axle with your foot and you'll gain several inches of clearance.

7a)If you choose to replace the spring isolators, they just pull right off. They may be kind of crusted on there, so pry them up with a screwdriver or something and then clean off the mount. As mine is a West-Coast car, there is not much rust to speak of. For you East-Coasters, I'm sorry but you will probably have LOTS of rust here and you'll at least want to get out a wire brush and some Hammerite/Rustoleum to encapsulate and neutralize the rust.

Spring seat with spring isolators removed


7b)Install spring isolators with tab going into hole on spring seat. The bottoms have a tab on both front and rear axles, but the tops just pop into place.



8)Installing the new springs comes next. They are much stiffer though and a little harder to get in. Make sure the end of the spring lines up with the stop-tab in the rubber isolator at the bottom. Step on the axle again as you push down on the spring and push it in there. I'm only "average" strength and got it in there without much trouble.

Springs installed


9)Install end links. Again, may need to do some jacking to get the axle in the right position. Torque spec is "pretty darn tight". I would say around 70 ft-lbs would be good. I'm not big on torque specs except for critical areas (wheels, bearings, engine internals, crank pulley nut).

10)Install shocks. On top, place one of the included "cup" washers facing up as well as one rubber bushing. Slip this into the open hole in the body and drop the base into the receptacle in the axle. Then, use the new hardware you just bought to bolt it all together. It goes "Bolt, washer, bar pin, axle, washer, lock nut". Torque spec is 21 ft-lbs.

Shock installed


Bottom of hardware (a little fuzzy)


11)Look over everything you have touched to make sure it is tightened.

12)Put wheels back on. This required me to jack up the axle so I could fit the wheels on.

13)Put the truck on the ground.

14)Go back into the engine bay and finish off the shocks. Place one rubber bushing face down, one cup washer face down, and the new locknut. The Bilstein locknuts were 17mm (again, you need a deep socket). I rattled it down with the impact driver, but the correct torque spec is 26 ft-lbs if you care. Re-attach hose and plastic clip on top of driver's side shock.

15)Don't forget to torque your wheel nuts to 100 ft-lbs.

Rear Axle

Unfortunately, I was getting hungry so I wanted to wrap up quickly so I didn't stop to take pictures much for the rear. My apologies. It is easier than the front axle, so once you've done that, the rear is easy.

1)Loosen lug nuts.

2)Jack rear end up. Again, you will need the frame rails for your jackstands, so jack in an area where you keep access. If you have the skid plate back there, I've successfully jacked from it with no drama. If you have the "brush guard" I wouldn't recommend it.

3)Remove wheels.

4)Support axle with jack.

5)Remove shocks from vehicle - both top and bottom bolts take a 15mm socket. The axle will want to droop a lot at this point which is why you have a jack under there.

6)Remove rear sway bar end links - this will make the axle want to droop even more.

Ready to droop. In this pic, I hadn't removed the shock yet.


7)Lower axle with jack.

8)Pull out springs in the same manner as the front. If you need more clearance, you can step on the axle or jack up the OPPOSITE side of the axle (your side will droop even more).

Springs out


9)Remove bump stops from receptacle. They should just wiggle out. You can also use a pry bar or big screwdriver to pry them out. Clean up the dirt on the bump stop and in the receptacle. It will be much easier to re-install.

10)Put some grease around the lip of the receptacle for said bump stop.

11)Inserting the rear springs is a little tougher than the front, but still not that bad. First, jack up the opposite side of the axle to give you max droop. Slip the bump stop up inside the spring. Insert the top end of the spring over the retainer. Align the bottom of the spring to line up with the stop in the lower spring isolator. Then you'll need to wiggle that bump stop back into its home in the axle. I used a big screwdriver to pry it into place.

12)Jack up the whole axle again and install shocks. Top bolt torque spec is 80 ft-lbs, bottom is 85 ft-lbs.

13)Reattach sway bar end links. You'll need to jack up on the axle and maybe jack one side a little to set the preload and actually fit the bolt through the hole. Torque spec same as the front. "Pretty darn tight". 70-75 ft-lbs.

14)Reattach wheels.

15)Put truck back on the ground

16)Torque lug nuts to 100 ft-lbs.

The Results

The overall install only took me 3 hours start-to-finish including a trip to Lowe's to get the shock bolts and stopping to take these pictures for you. If better prepared, I could do it in 2 hours. I would say it is a pretty easy job, maybe 4 on a scale of 10 with wiper blades a 1, radiator replacement a 5, and rebuild of engine a 10.

The ride is firmer than stock, but not harsh or bumpy. Body motion is well-controlled by the Bilstein shocks. The overall stance is much more aggressive. The handling and steering response is greatly improved. As it has only been installed a few hours, I can't comment on off-road behavior, but I have a trip planned for Feb 5th to try it out off road.

The steering wheel was only off-center by maybe 5º to the left. I test drove it and it was barely noticeable. Nonetheless, I fixed it. Loosen 2 15mm nuts on the drag link, shorten drag link 1/4 turn, then re-tighten nuts. Problem solved.

Measurements
Front Fender-to-hub Before: 17-3/8"
Front Fender-to-hub After: 19-3/8" (net lift 2")
Rear Fender-to-hub Before: 18-1/4"
Rear Fender-to-hub After: 20-1/4" (net lift 2")

[edit]After New Spring Isolators Installed
Front Fender-to-hub After: 20" (net lift from isolators 5/8")
Rear Fender-to-hub After: 21" (net lift from isolators 3/4")

[edit]Added 3/4" spacers to the front springs to level it out
Front Fender-to Hub After: 20-3/4"
Rear Fender-to-Hub After: 21"

Measurements were taken with vehicle empty, one car seat in back, one 40-lb tray of recovery gear in hatch area. Fuel tank 1/4 full.

I was surprised that I didn't get more than 2" lift from it based on my sagged springs. At 17-3/8" Fender-to-hub, I had assumed that it was the spring that had sagged over time. Revelation: It may be that the spring isolators are the real culprit for typical WJ sagging. I plan on replacing the spring isolators as well as adding a 3/4" spacer to the front to level the vehicle. See newly-added "Spring Isolators" section for more info.

[edit] I recently read over my build sheet and found that I did in fact have Upcountry suspension on my Overland, so I was sagging from both springs and spring isolators. The total amount of sag from worn-out parts was 1-3/8".

Pictures

Before


After


With 3/4" spacers added up front.
 
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21
#30 ·
Lastly said:
Sounds good! Thanks so much for the offer. I was originally planning on waiting for summer to do the lift, but got a bigger than expected tax return so thinking about doing it soon. The shocks need to be replaced anyways, so sounds like a good excuse to me! You might be hearing from me soon! LOL.

After the lift I'm going to put a set of rock sliders on from here:
http://www.jcroffroad.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=WJSL

My buddy moved from here out to Michigan and got hooked up at this fab shop with a job. They make sweet stuff. I like the class III's because they kind of angle up around and look cleaner.

PS I work in Redmond too, you a MSFT'er?
 
#33 ·
If you plan on running 245/70/17's on JK rims. Be prepared to do some trimming of the splash shield and re-adjustment of the front bumper mounts. I ended up taking the bottom clips out of the bumper facia and pulling it out. And then drilled new holes for the clips. Also had to remove the factory mud flaps. It may not be as bad with a less agressive tire, but the Duratracs still seem to make contact on large dips at full speed. I may end up going to 3" coils. Cheaper than new tires.::facepalm:
 
#36 ·
Well my spring isolators took 2 days to ship and are on 3-day shipping. ETA on them is 01/24 which means I WON'T be doing them this weekend as planned. I'm sure glad I paid extra for rush shipping!

[edit]RockAuto get them to me on Friday instead of Monday. So, I was glad to get them on time and got the job done this weekend.
 
#37 ·
Well my spring isolators took 2 days to ship and are on 3-day shipping. ETA on them is 01/24 which means I WON'T be doing them this weekend as planned. I'm sure glad I paid extra for rush shipping!
Could you explain real quick what the spring isolators are? I've done lifts and leveling kits on stuff before and have never run across that term. Should I be considering replacing them as well when I do my BDS lift?
 
#42 ·
@Bowhunt - the replacements were $102 +/- and I overpaid for rush shipping which won't be here on time. Frown. That's a better price than O'Reilly though, so I guess there's that.

@Metalhead - I can already fit mostly under there already. Well enough to change the oil even using a creeper The extra 2" lift will help.

@MYGrandcherokee - I provided DIRECT links to the places I purchased the springs from. Do your own clicking. Also, there is a 10% discount link from BDS in my original post. Go click it.
 
#43 ·
Well, I did not expect this, but the RockAuto order came on Friday 01/21 instead of Monday 01/24. So, I will be installing all the new isolators, updating the thread with part numbers, and providing before/after pics/measurements. And also teaching the fiancee a little about cars! :)
 
#44 ·
Man I put 31x10.50x15 BF Goodrich KM2's on with the OME coils and I had to cut an *** load of my bumper away and I am still rubbing on something when going over snow bumps. 3" of lift and beefy 31's=plenty of trimming.
 
#46 ·
Original thread has too many pictures so I am putting pictures of the upper isolators. They were less collapsed than the front, but easy to replace.

Upper Front


Upper Rear


Assembly with new isolators


Installing the spring isolators requires essentially doing the entire job again (other than completely removing the shocks). So I made my fiancee do it! She has never done ANYTHING to a car other than add oil and gas...never turned a wrench. I made her do everything and SHE did the work in 2 hours. I told her what to do and gave her the tools. That's right, a GIRL with ZERO EXPERIENCE did this. So, get out there and DO IT!

 
#47 ·
Wow that one isolator looked like HELL! I am seriously hoping mine don't look like that. Thanks for the pics now I know what you look for.

I have one question - the bushings that come with the front shocks, does the "bulge" on them face away from eachother or toward eachother? I'm looking at mine now and I can't tell how they'd go. Same question for the "bulge" on the washers too.

BTW she's a keeper. If I told my wife to do that kind of work she'd tell me where I can shove my torque wrench!
 
#49 ·
Wow those look pretty bad. Hmm. I'm going to gamble and not order the parts until I know it is necessary. But those pics don't instill any confidence!

One more question - would the use of spring compressors make this portion of the job any easier? I'm just thinking down the road if I have to replace the isolators, would it save me any time? I already have them.

Thanks again for all this info and answers, I'll be referring to it often once all of my parts arrive!
 
#52 ·
I posted the new dimensions in the original post. But, you are correct. The spring isolators ARE the source of normal WJ sag. Here is the new info that I added to the original (for all those who are subscribed to the thread).

Spring Isolators
This section is a new addition. My lift wasn't quite as high as I wanted and I had inconsistent lift height all around. After seeing what new isolators looked like, I was certain that mine had really collapsed. The results are perfect. The conclusion I can make: collapsed spring isolators are the real source of WJ sagging. Upper isolators are not as much the problem. My uppers were distorted but not totally junk. The lowers were really quite collapsed.

Here's the part numbers you need:

Upper Front: Mopar: 52088 257AB, Moog: K160040, Raybestos Professional: 5771-704
Lower Front: Mopar: 5208 8401, Moog: K160041, Raybestos Professional: 5771-705
Upper Rear: Mopar: 5208 8346, Moog: K160061, Raybestos Professional: 5771-716
Lower Rear: Mopar: 52088 402AB, Moog: K160042, Raybestos Professional: 5771-706

I went with the Raybestos Professional line over the Moog due to warranty, price, pictures, and reputation. The total cost for spring isolators was right around $100 for all 8 from RockAuto If you are looking to save some coin, just get the lower ones. They are the most important and were far more deformed. I REALLY recommend it so you don't have to do this job twice.

As a side benefit, the level of road noise is also greatly reduced and pothole impacts are much softer. Again, I really recommend replacing these, even if you are just getting a budget boost. You will see better results from any lift or even no lift at all - this will put you back to stock height.

Added to instructions:
7a)If you choose to replace the spring isolators, they just pull right off. They may be kind of crusted on there, so pry them up with a screwdriver or something and then clean off the mount. As mine is a West-Coast car, there is not much rust to speak of. For you East-Coasters, I'm sorry but you will probably have LOTS of rust here and you'll at least want to get out a wire brush and some Hammerite/Rustoleum to encapsulate and neutralize the rust.

Spring seat with spring isolators removed
This image has been resized. Click this bar to view the full image. The original image is sized 1024x768.


7b)Install spring isolators with tab going into hole on spring seat. The bottoms have a tab on both front and rear axles, but the tops just pop into place.

This image has been resized. Click this bar to view the full image. The original image is sized 1024x768.


Complete list of measurements/results:
Measurements
Front Fender-to-hub Before: 17-3/8"
Front Fender-to-hub After: 19-3/8" (net lift 2")
Rear Fender-to-hub Before: 18-1/4"
Rear Fender-to-hub After: 20-1/4" (net lift 2")
[edit]After New Spring Isolators Installed
Front Fender-to-hub After: 20" (net lift from isolators 5/8")
Rear Fender-to-hub After: 21" (net lift from isolators 3/4")
 
#56 ·
This makes me want to put new isolators in as well. I would like to know how your Bilsteins hold up to some rough roads. I have already been through 2 sets of shocks now with these coils. And I can't seem to find a happy zone. We have some TERRIBLE roads here in the midwest ,so daily driving is like a washboard. I blew out another front shock the other day. The RC nitro's are like riding in a Radio Flyer being pulled by Ivan Stewart through Baja!
 
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