[Waternut]

So after a ton of time debating and researching a 4 link rear, I decided to pull the trigger. In 2 afternoons after work, I was able to strip everything off the frame and axle. Figured I was making quick and solid progress but the tricky part is starting now.

The basic plan is to keep the stock fuel tank but maximize as much wheelbase as I can muster without going off the deepend. If I decide I need more wheelbase later, I'll lengthen the links. I am using Fox 14" coilovers and will be using square links made of 2" x 0.25" wall steel. Most of the brackets came from Barnes4WD and the joints are 1.25 Trailgear Creeper joints.

Things I've already learned so far...
1. I've spent months researching and hours under the Jeep measuring and planning but that's already going out the window.
2. At full bump, there is NO room under the jeep for any parts.
3. Speaking of room... I've got an engine hoist holding up the back of the jeep so I can raise it high enough to roll the axle out and jack stands under the frame for when the engine hoist needs to move to get the axle out of the garage. Then I've got a jack under the trans to hold it up since I need behind the skidplate and a jack stand under the pinion to hold it up. There's no room for me under there either.
4. Consumables are getting consumed at an alarming rate. I've used 4 flap discs, 5 cutoff wheels, and 4 plasma cutter tips already.
5. With a plasma cutter, welder, grinder, cutoff wheel, and a fan for cooling me, the wires are always tangled.
6. The frame angles outboard under the skidplate so even a 20° fitting and maxing out the joint flex will not get my links pointed to the center of the axle so on to plan H at this point...haha

 

[wizekrakr]

Can't wait to see all of that go together. I used the Gen Right kit to link the rear on my 89. Some lessons I learned. I was able to move the axle back 1 inch. I figured that by checking clearances at full stuff. What I didn't take into account was that the rear axle will probably never be at full stuff on both sides at the same time. If one side is at full stuff the other side is in droop. I could have moved the axle back another inch or maybe more and still not hit the stock tank skid. Also I wanted to keep my E-brake operational. Had to completely redesign the brackets and cable set up for that. With the rear axle out, now is the time to fab and build a skid plate for it if you want one. So much easier than when under the jeep. Looking forward to see the progress you make.

 

[Waternut]

What I didn't take into account was that the rear axle will probably never be at full stuff on both sides at the same time. If one side is at full stuff the other side is in droop. I could have moved the axle back another inch or maybe more and still not hit the stock tank skid.

I'll look into that but I always figured the axle rotated about the center so even stuffing one side still puts the diff in about the same spot. Although, I guess if it's even an inch lower, that will give some additional clearance with the angles of both parts. Either way, this is how I'm currently positioning the rear axle at full bump. Once everything is in place, I'll adjust the link lengths slightly as needed. I'm probably going to cut off that little roll in the tank skid as well since it's almost 1/2".

 

[Waternut]

So I had to modify my plans for the upper frame link mounts due to the angle of the frame where I wanted to mount them. I suspect most people mount everything further back where the frame is straight. Mine are basically over the last skid plate hole. Since I was trying to maximize link length, I figured the best way to push the frame mount angle out enough was to box the frame around the mount to get the angle I need. That caused the lower mounts to get pushed more inboard to make room for the joints. This actually ended up being a good thing for roll axis angle but reinforcing that lower mount is going to more critical. I'll probably add another piece to reinforce it once I get it positioned. There will be a lot of load on that lower link which is translate into a lot of torque on the frame.

I also learned that mounting the lower axle mounts as far as I could outboard backfired a little. I couldn't get the bolts in. I debated cutting the tack welds and moving them inboard but decided to just cut the dust shield on the axle instead since everything else was positioned pretty well. I thought that would be enough but I'll have to take the brake rotor off anytime I need to pull that bolt since that was in the way as well. Hopefully, I won't have to mess with those bolts that often though.

 

[Waternut]

Well I've burned through about 4 lbs of welding wire so far and got forced to stop since all the stores are closed. It's coming along nicely though. There have certainly been several hiccups but so far nothing the plasma cutter and some new welds can't fix. The diff does lightly touch the gas tank skid but that is also with both tires at full bump. I'm more concerned with bottoming out on the tub so I'll probably set my bump stops here, shave the tub support slightly and let the bumps squish a bit.

 

[Randonexplosion]

Are you planning on tying the link bridge in anywhere else? All of that torque can wreak havok as the pinion tries to climb. Ive seen people 1/4" plate trusses warp.

Along with my Artec Truss I used their pinion support that bolts on the flat spot with 3 holes next to the pinion snout.

Sent from my SM-N960U using Tapatalk

 

[87TPIYJ]

Are you planning on tying the link bridge in anywhere else? All of that torque can wreak havok as the pinion tries to climb. Ive seen people 1/4" plate trusses warp.

Along with my Artec Truss I used their pinion support that bolts on the flat spot with 3 holes next to the pinion snout.

Sent from my SM-N960U using Tapatalk

I was just about to say the same thing. Make a bracket that will tie those holes into the truss. If you dont you are more than likely going to rip the truss off. There is a ton of force on those uppers. Also, on your frame side like brackets the fillet weld that runs up along side the mounting holes looks cold. Might want to double check that one weld. Other than that looks like you are off and running. Good start.

 

[Waternut]

I was originally going to add some gussets to the truss on the front and back of the axle tube but I guess tying it into the holes on the diff housing would make more sense.

Impressive eye on the cold weld. I thought that one looked funny too so I welded the other side rather than just plopping another bead on top of it.

 

[StanF]

...The diff does lightly touch the gas tank skid but that is also with both tires at full bump....

Do you have a 1" body lift? If so, it looks a 1" gas tank lift would give you a enough clearance between the diff and gas tank. And give you more ground clearance for the gas tank, which is always a good thing.

I've rolled backwards off a large ledge before after a failed climb, and managed to hit full bump on both sides. It's definitely a rare occurrence, but it can happen

There's several threads on gas tank lifts. Here's one:

https://www.jeepforum.com/forum/f12/yj-gas-tank-lift-1520623/

 

[Waternut]

Do you have a 1" body lift? If so, it looks a 1" gas tank lift would give you a enough clearance between the diff and gas tank. And give you more ground clearance for the gas tank, which is always a good thing.

I've rolled backwards off a large ledge before after a failed climb, and managed to hit full bump on both sides. It's definitely a rare occurrence, but it can happen

There's several threads on gas tank lifts. Here's one:

https://www.jeepforum.com/forum/f12/yj-gas-tank-lift-1520623/

Interesting... Yes I do have a 1" body lift. I'll look into the gas tank lift because that would be a very valid option, if possible.

 

[Siva283]

I'll look into that but I always figured the axle rotated about the center so even stuffing one side still puts the diff in about the same spot. Although, I guess if it's even an inch lower, that will give some additional clearance with the angles of both parts. Either way, this is how I'm currently positioning the rear axle at full bump. Once everything is in place, I'll adjust the link lengths slightly as needed. I'm probably going to cut off that little roll in the tank skid as well since it's almost 1/2".

That roll is the straps for the gas tank. You can just take the straps off to get rid of it but then you will need to find another way to secure tha tank.

 

[Waternut]

That roll is the straps for the gas tank. You can just take the straps off to get rid of it but then you will need to find another way to secure tha tank.

Thanks for that info. I'll have to drop the tank to figure out a tank securing solution because I cut that roll off not understanding it's purpose. Guess I'll be doing the gas tank lift for sure now. I could probably weld that roll back on if the tank is high enough but we'll see.

 

[Siva283]

Thanks for that info. I'll have to drop the tank to figure out a tank securing solution because I cut that roll off not understanding it's purpose. Guess I'll be doing the gas tank lift for sure now. I could probably weld that roll back on if the tank is high enough but we'll see.

I had to replace mine because My Jeeps PO thought things like that and washer fluid and seatbelts werent necasary. I got replacement straps from Autozone for $30. They didnt have that roll. They were flat T's that sit much more flush with the Skid that might solve both your problems.

 

[Waternut]

I had to replace mine because My Jeeps PO thought things like that and washer fluid and seatbelts werent necasary. I got replacement straps from Autozone for $30. They didnt have that roll. They were flat T's that sit much more flush with the Skid that might solve both your problems.

Could weld that strap to the inside of the skidplate too since I've got to drop it anyway. Thanks for the insight.

 

[Randonexplosion]

It's a little late but is there a reason that you didn't want to go with something like the Artec truss and mount the link brackets horizontally? I'm guessing it was the flexibility of being able to put your axle end vertical separation the way you wanted it.

Hopefully you will have enough room for the coilovers between the frame and tire with the wheel spacers. It gets tight very quickly.

 

[87TPIYJ]

Almost forgot. The 12 ton HF jack stands and these were a life saver for doing my suspension.

Sumner ST-881 Hi Fold-A-Jacks with V-Head https://www.amazon.com/dp/B002N2I3BG/ref=cm_sw_r_cp_api_i_b6jlDbF029AQV

 

[Waternut]

It's a little late but is there a reason that you didn't want to go with something like the Artec truss and mount the link brackets horizontally? I'm guessing it was the flexibility of being able to put your axle end vertical separation the way you wanted it.

Hopefully you will have enough room for the coilovers between the frame and tire with the wheel spacers. It gets tight very quickly.

Cost was part of it, flexibility was the main part though. It looked like most 8.8 trusses were designed to mount in a specific location and with the SYE, that location wouldn't work for me without modification. I figured if I have to modify something, I might as well make it from scratch since it'll be a lot cheaper and usually takes the same amount of time. It wouldn't function as a true truss but I hadn't really read anything that said the 8.8 really needed one either.

Almost forgot. The 12 ton HF jack stands and these were a life saver for doing my suspension.

Sumner ST-881 Hi Fold-A-Jacks with V-Head https://www.amazon.com/dp/B002N2I3BG/ref=cm_sw_r_cp_api_i_b6jlDbF029AQV

Yeah I looked into some 12 ton jackstands but I also figured that would be $100 for one job and then I'd have to find a place to put them in my tiny garage. I do like the concept of the screw jacks though... it's a bit late for this project but I may look into getting a set of those things.

 

[Waternut]

So the links are in, skid plates back on, and the axle is centered. I only checked full up and full bump last night but I've got enough travel to accomodate the travel on my 14" shock pretty easily. I did have to cut slots in my flat skid plate to accomodate the lower frame mounts. I also added a link truss support down to the diff housing. It's just welded for now but since the diff is cast, I plan to drill holes as well.

I did a test fit on the rear angled bump stop and it will fit very well on the frame and once I move it and drill new holes, it will contact the lower link nicely. I'll outline that later.

I'm really worried about that exhaust though. That looks like it's going to be a bear to route it and it's way too loud dumping underneath the jeep.

Just for sh*ts and giggles, I looked at what I've consumed during this process prior to mounting shocks and frenching in the shock towers:
6 - 4.5" flap discs
8 - 4.5" cutting wheels
5 - plasma cutter tips
5 lbs of welding wire :eyebulge:

 

[daddyjeep87]

Oh yeah.... looking good. Exhaust can be tough with long arms. Can you sneak it between the links there on the passengers' side? you won't want it too close to the joints so you don't heat them up, but there may be just enough room there. I ended going over the upper link right after the tub steps up. You can kind of see what I mean in this pic.

 

[Waternut]

Yeah I was thinking between the links might be tricky. I may just stick a downturn tip on it until I can figure it out but depends on how things play out and the amount of time I have.

Sent from my Pixel 2 using Tapatalk