Rear track bar contacting gas tank skid after tummy tuck

[Chris]

So if I'm understanding this correctly, when you rotate the pinion back, the track bar is getting "rotated" along with the axle and then interfering with the gas tank. I'll be honest, I've never messed around with my rear track bar personally, but to me, it would seem that the mount for the track bar on the axle side should be on top of the axle (or at least the track bar should be parallel to the axle). I would think you'd have to relocate the axle side mount forward, moving the track bar forward. If you moved the frame side mount forward, you'd have a pretty good angle on the track bar relative to the axle.

Again, this is just wild speculation on my part because I've never had to do it myself.

Correct. If you rotate the pinion back (or upwards) it's causing the track bar to be rotated back with it. This is causing the upper portion of the rear track bar to contact the fuel tank skid. If you did what you are describing though and had the axle side bracket for the track bar facing straight up (instead of the angled bracket that it has now), then you'd bring the other side of the track bar more in contact with the gas tank skid as well.

 

[bobthetj03]

Is there a possibility you got the wrong TB per application? Something else to look into.

 

[JDS123]

Correct. If you rotate the pinion back (or upwards) it's causing the track bar to be rotated back with it. This is causing the upper portion of the rear track bar to contact the fuel tank skid. If you did what you are describing though and had the axle side bracket for the track bar facing straight up (instead of the angled bracket that it has now), then you'd bring the other side of the track bar more in contact with the gas tank skid as well.

Maybe on top isn't the best way to describe it. If you made the track bar parallel to the axle, would it clear? Your idea of moving the frame side mount forward makes sense to me. I don't think there is a way to fix it on the axle side (I had which way it was angled reversed in my head).

 

[David Kishpaugh]

Got off the phone with Jeff at Rokmen. He said this is definitely not normal, and he's seen other TJs like mine with the same mods, same skid plates, and same amount of lift that haven't had this issue at all. He said usually the issue is that they didn't have the angled CV bracket for the rear track bar, but I mentioned I have that bracket. He said if that's the case, I shouldn't be having this issue.

He said he's going to take a look at my photos and let me know what he thinks. He said that given that I'm only at 4" of suspension lift that this is not common by any means.

I disagree. It is very normal to see especially with a 4" lift and tummy tuck with a stock tranny mount.

 

[bobthetj03]

This will be good intel for your TT thread @Chris. That is, once you get it sorted out.

 

[Chris]

I build weld on relocation brackets with a brace to solve this issue. The angled bolt on brackets still smash the track bar into the crossmember with shocks matched to a 2" bumpstop. Guys with 15" and longer collapsed shock lengths in stock mounts don't have enough uptravel to hit it, but the axle end bolt can still dig a hole in the tank if the lower short arms are 16" or longer.

Moving the frame side spring perches won't help the track bar clearance a bit. It puts the track bar bolt into the spring and still doesn't land the bumpstops square, which is why I prefer rotate the lower perches unless I'm building a triangulated 4 link.

The compressed length on my rear Rancho shocks is 15.063", so maybe I'd be just fine... barely?

Rear lower rear control arms are 15.75" right now, so I'd be fine in that department as well. But is sounds like the solution is your weld on rear track bar bracket. I assume it has much more of an angle than the JKS rear track bar bracket I have on there right now?

I need to find a way to get my Jeep to you... and get home!

 

[Chris]

Is there a possibility you got the wrong TB per application? Something else to look into.

Maybe, but it was just fine before I had to rotate the pinion angle up to such an extreme. What would solve this is if the JKS rear track bar bracket had a more extreme angle to it.

 

[Chris]

I'm going to have @David Kishpaugh pick it up for me and do his magic on it. Clearly I've done all I can do as a DIY home mechanic. This is going to take the work of a professional to get right.

 

[David Kishpaugh]

The compressed length on my rear Rancho shocks is 15.063", so maybe I'd be just fine... barely?

Rear lower rear control arms are 15.75" right now, so I'd be fine in that department as well. But is sounds like the solution is your weld on rear track bar bracket. I assume it has much more of an angle than the JKS rear track bar bracket I have on there right now?

I need to find a way to get my Jeep to you... and get home!

It's not more angle. I move the mount forward. The angle of my bracket is what a stock track bar needs with the high pinion angle to eliminate binding the bushing.

 

[Chris]

It's not more angle. I move the mount forward. The angle of my bracket is what a stock track bar needs with the high pinion angle to eliminate binding the bushing.

Ahhh, that makes sense! I can see how that would work too. Right now that JKS bracket isn't forward enough, so it's pushing the track bar back into the gas tank skid.

 

[KMET]

I'll try my best to explain.


@ 4", the coils compressed, force axle to rotate back towards gas tank skid, relocators bring the springs back to vertical, or perpendicular to the axle eliminating that force. Thats my best guess...

 

[Chris]

Oh crap... I got under the Jeep just a moment ago and looked upwards at my rear track bar and saw this:

Did I install the axle end of the rear track bar backwards?

 

[Chris]

Nevermind to the above. I verified that is the correct position for the rear track bar axle end.

 

[Chason]

How far out is your rokmen skid compared to the factory one? I have a LJ rubi with a 3.5 lift, tummy tuck & all that crap but no issues with factory skid.

 

[Blank]

strppers always make most things better

 

[Chris]

How far out is your rokmen skid compared to the factory one? I have a LJ rubi with a 3.5 lift, tummy tuck & all that crap but no issues with factory skid.

I didn’t measure, but visually it doesn’t appear to stick out and further than the factory skid.

 

[jjvw]

Fwiw, Several years ago, a friend added a Savvy tummy tuck into his 4" lift. He couldn't get the the pinion, control arms and track bar sorted out until several of us helped him cut and rotate all four control arm mounts and the track bar mount forward closer to the stock (unlifted) position. I forget the details on how this extensive of a fix was arrived at, but it seems to have worked.

 

[Chris]

Well, great news! The track bar doesn’t contact the fuel tank skid at all. Sitting on the ground, it really looks like it will. However, I cycled the rear suspension and I can confirm that even under full droop, it doesn’t contact. When the axle starts to drop, it obviously starts to fall down and forward at the same time. This is enough to pull the track bar away from the skid. So while it looks like it will contact, there’s maybe a little over a 1/4” of clearance between the track bar and the skid.

That just made my day! Now I just need to have @David Kishpaugh relocate these spring perches for me!

 

[bobthetj03]

Is he going to relocate the uppers or the lowers? Glad to hear about your TB clearance.

 

[Chris]

Is he going to relocate the uppers or the lowers? Glad to hear about your TB clearance.

I’ll go with whatever he suggests, but I have a feeling it’s going to be the lowers.

I’m going to get the exhaust lowered more today. That thing is way too close the floor pan after the tuck, haha. The buzzing is driving me nuts.