Rear track bar contacting gas tank skid after tummy tuck

[Chris]

I got my Savvy control arms installed tonight along with the Tom Wood CV driveshaft. The pinion angle is dialed in correctly, but I'm worried about the rear track bar.

The upper portion of it (near where it attaches to the frame) is overlapping with the edge of the Rokmen gas tank skid. I worry that if the drivers side rear tire were to fully droop (meaning the passenger side rear tire was stuffed), it would contact the fuel tank skid.

I haven't cycled the suspension yet so I'm not sure this is going to happen, but I'm almost certain of it just based off what I'm seeing visually.

Here's a photo looking at it:

And here's a photo look at it on the ground facing up:

The track bar was NOT doing this before I started rotating the pinion angle up to match the CV driveshaft. I had to rotate the pinion up considerably due to the increased angle that now exists after the Rokmen transfer case skid plate (tummy tuck) install.

If I rotate the pinion angle down to be much closer to where it would be stock, this issue goes away entirely.

I can't shorten the wheelbase in the rear to bring it in more either, because my lower rear arms are adjusted almost all the way in already.

I'm a bit torn on what to do here. I can't be the only one who has experienced this issue, can I?

I can't blame this on the Rokmen skid or the JKS rear bar. I blame it on the extreme angle of the pinion in order to match it with the driveshaft and the tucked transfer case.

 

[Rob5589]

One issue begets another. @jjvw may have some insight since he has done some extensive mods to his TJ.

 

[Chris]

One issue begets another.

Tell me about it.

It seems like the solution would be moving the frame side track bar bracket forward an inch or so. Actually, that would solve the issue I think. But that seems like an unreasonable solution, because I'm sure I would have heard of other people doing such a thing if it was necessary.

Pushing the pinion so far up caused it to rotate the track bar back towards the fuel tank more. Hmmm... So maybe a track bar bracket with an even steeper angle than the JKS one. That seems like it would do it too.

I'm definitely open to suggestions as to what the right way to go about solving this issue is.

 

[Jeepaholic]

Do you have the bracket that jks says is required for double card an driveshafts? I believe that angles the track bar forwards?

 

[bobthetj03]

One issue begets another. @jjvw may have some insight since he has done some extensive mods to his TJ.

Yeah, he eliminated the issue by eliminating the rear TB.

 

[bobthetj03]

Tell me about it.

It seems like the solution would be moving the frame side track bar bracket forward an inch or so. Actually, that would solve the issue I think. But that seems like an unreasonable solution, because I'm sure I would have heard of other people doing such a thing if it was necessary.

Pushing the pinion so far up caused it to rotate the track bar back towards the fuel tank more. Hmmm... So maybe a track bar bracket with an even steeper angle than the JKS one. That seems like it would do it too.

I'm definitely open to suggestions as to what the right way to go about solving this issue is.

this is one of the issues I was concerned about when picking a TT. I hope you can find an easy solution.

 

[Chris]

Do you have the bracket that jks says is required for double card an driveshafts? I believe that angles the track bar forwards?

Yes, I have that bracket. That angle works fine for a 4" lift without a tummy tuck, but once you add that tummy tuck the pinion angle gets even more extreme.

this is one of the issues I was concerned about when picking a TT. I hope you can find an easy solution.

It makes you envy the JKs with their already flat bellies!

 

[Chris]

Apparently I'm not alone either, check this out:

https://www.reddit.com/r/Jeep/comments/4nt4m0/tj_rear_track_bar_hitting_fuel_tank_need_advice/

I'm also finding a lot of other Google search results with the same issue, yet no solid answer (well, not that I've found yet).

 

[bobthetj03]

Welcome to MY world. Sorry, doesn't help yours.

 

[glwood]

It makes you envy the JKs with their already flat bellies!

Yeah, but if you've noticed, the JK frame itself hangs lower than a TJ frame. I don't envy that.

 

[bobthetj03]

A TT in a TJ is a commitment.

 

[KMET]

Had this problem before relocating rear spring perch.

 

[Rob5589]

Reading around revealed a few different fixes; reversing the track bar if possible; bending the tb; relocating the axle bracket; running stock tb with custom brackets; removing material from skid for clearance.

 

[glwood]

Don't know much about LJs personally, but am wondering - is this not an issue with them due to the gas tank being in a different location? Or is it the same as a TJ...?

 

[Chris]

Had this problem before relocating rear spring perch.

How did relocating the spring perch solve it? In my mind I can't see how that would do anything.

Reading around revealed a few different fixes; reversing the track bar if possible; bending the tb; relocating the axle bracket; running stock tb with custom brackets; removing material from skid for clearance.

Yeah, I'm just trying to figure out which is the right way to go about it. Or perhaps there's more than one right way.

Don't know much about LJs personally, but am wondering - is this not an issue with them due to the gas tank being in a different location? Or is it the same as a TJ...?

I don't think the LJ would suffer from this issue to begin with, mostly because with the longer rear driveshaft, you wouldn't need to rotate the pinion up to such an extreme angle. I could be wrong, but that's what I think.

 

[glwood]

How did relocating the spring perch solve it? In my mind I can't see how that would do anything.

I don't think the LJ would suffer from this issue to begin with, mostly because with the longer rear driveshaft, you wouldn't need to rotate the pinion up to such an extreme angle. I could be wrong, but that's what I think.

Apparently they do, as @KMET did with his LJ; though, like you, I can't see how relocating the spring perches would solve the issue.

 

[Chris]

Apparently they do, as @KMET did with his LJ; though, like you, I can't see how relocating the spring perches would solve the issue.

Yeah, I can see how relocating the spring perches would solve the bowing issue with the rear springs, but I don't see how it's going to move the track bar away from the gas tank skid.

I'll tell you what... With a tummy tuck, you end up getting a lot more than you bargained for... sheesh!

 

[JDS123]

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, which it isn't in the second photo you posted). 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.

 

[Chris]

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.

 

[David Kishpaugh]

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.