Hi everyone,

About a year ago I went through a streak of bad wheeling trips, 3 nearly back to back ones. What I mean by bad is, just plain bad luck. I broke and bent suspension parts doing easy trails. My engine and transmission are still not running properly. Being a student I had to put up wheeling for a while and save cash to fix and service everything.

I got the truck running again but a vibration under suspenion articulation started. I took it to 3 shops (2 of them off-road specialists) and no one could diagnose the problem. It would vibrate (similar to the sound and feel tire rubbing in wheel well) when you go over something as small as a speed bump at an angle.

I lived with the problem for the past year as it did not affect daily driving. Recently I was in for an oil change and while my truck was up on the lift I was checking as much as a could from behind the yellow line and I noticed fresh rub marks on the side of the gas tank. Getting a closer look it looks like when flexing the driveshaft is getting pushed over and hitting the gas tank, thus causing the noice and vibration.

During all the carnage last year I broke my left rear shock and my rear lateral bar (panhard bar). I replaced the lateal bar with a new one from Joe (Darlington Off-road), who IIRC made it a little longer to accomadate for the lift and tires.

Does it makes sense to think that it might be too long and actually shifting my rear axle over?

Thanks in advance for your input!

Ashby

Does it makes sense to think that it might be too long and actually shifting my rear axle over?

Yes. But it is a tradeoff. The panhard bar locates the axle laterally. A longer one is needed if you want to maintain "center" when the vehicle is lifted. It also allows for more travel before things bind. But...this means that as the suspension is compressed it is moved laterally (in your case, left) farther than it would be with the stock bar. In otherwords, when the axle is compressed to the point of the original ride height, it is no longer in the exact same location. Hence, rubbing.

Just clearance what you need to and be happy.

Michael

Thanks for the response. I got the first part of your post, makes sense. What are you suggesting though? By clearance what do you mean?

Thanks!

By clearance what do you mean?

Make it so the two pieces that are interfearing with eachother, no longer do so. Is it rubbing on the tank or the skid plate? Either cut/grind the skid as needed, or maybe massage the tank a bit to make room for the driveline? It will depend upon how much interfearance we are talking about here.

Another thing to do is to make sure that the rest of the suspension is tight/straight. If you've bent things, maybe something is still tweaked. Without seeing it in person, it is hard to give you any more advice than that.

Good Luck,
Michael

by massaging the tank, I take it you mean a hammer <img src="/forums/images/graemlins/notooth.gif" alt="" />

Hi Ashby

I am glad to hear that you are not quitting the wheeling... As for the vibration, I am not sure it's related to anything you mentioned:

1. My pahnard rod is also very long. My current suspension setup gives me huge flex. But I have no vibrations under any condition.

2. The rear driveshaft on my Rodeo also made a deep depression/cut into the gas tank skid plate, but I never noticed when and how this happened. No vibration.

Ahsby, may be something shifted in your rear suspension and it must be re-aligned (although I have no idea how the rear alignment can be done). Other than that, I have no idea.

Thanks for the responses.

If Oleg's is not hitting then it must be something else.

Ashby

Ashby, your tires are bigger than mine, and your shocks are shorter than mine. May be, this is the reason why your tires can rub. May be, you need some bumpstop spacers. I installed 2" bumpstop spacers on my vehicle, I got them from Darlington. But I am not sure that this is the problem you have.
Is this possible that you bent something in the driveshaft ?

speaking of driveshafts, are you running a one piece or the carrier bearing type shaft. I know my carrier bearing was wearing out and would cause vibes when the rear axle moved around.

For all intents and purposes, and assuming that signatures are accruate, a 265/75-16 is a 31x10.5 (I am assuming this is what Oleg has). So, I doubt that is the issue. As for shocks, the bump stop should be limiting compression, not the shocks. So that should not be an issue. I guess it *could* but 4Play said it was not a tire rub issue.

As for a "rear" alignment. I do not think there is much to misalign on these rigs. Either a joint or bushing is worn out or something is bent. My guess is it really is the panhard bar shifting things far enough to cause a problem.

I do suggest reshaping the tank for clearance, instead of the self-clearance method. Letting it rub runs the risk of wearing a hole in the tank. If you thought vibrations were bad, a flaming ball of fire is marginally worse.

Good Luck,
Michael