XJ Pulling to Left only in 4WD - Truetrac?

After running trail 12 at Tellico in January, and my '96 XJ sitting until last weekend, I found that in 4WD on the street, it pulls violently to the left. This is hardly noticeable in 2WD, if at all. I pulled the rear shaft and have driven with only the front shaft in and it made matters worse.

I've checked the obvious, brake calipers, bushings, broken parts, control arms, track bar, frame mount, U-Joints, Axles, everything seems to be okay. And again, it only happens in 4WD. I put the front on stands and turned both wheels manually. No noise, tires spin the same, same amount of effort needed to turn them from either side. I put the tranny in 4th gear and started the engine. Under power, both sides still turn the same. I blocked each wheel independently, and the other wheel still turned, although it did make a bit of noise, somewhat of a screaming noise, which definitely was coming from the diff.

I popped the diff cover last night and ran out of workable light before I could do much inspecting. The gear lube was in excellent condition (been in there for about a year) with no debris floating in it. Nothing was stuck to the magnetic plug either. No visible signs of anything wrong, after cleaning the TrueTrac and diff case with brake cleaner.

Hopefully, tonight I can lift the front again and move the wheels with the diff cover off to see if anything shows up.

Has anyone had this issue before? The only odd thing I found was that in removing the front shaft so I could have it balanced, I found that the slip yoke was stuck tight. I had to pry it out of the yoke with a small pry bar to free it. I doubt this had anything to do with the front end pulling, but nevertheless, it was there.

I thought about calling TracTech today to see if they can recommend anything, but I've never heard anything good about their tech support and the part is out of warranty, so they might not talk to me anyway.

Any advice or experience you'd care to share will be greatly appreciated!

Thanks!

did you check tire wear or tire pressure?

Yep. Sorry, forgot some of the checks I went through. Pressure is the same on both tires. I even swapped one from the back on each side, just to ensure it wasn't a belt separating or something. It's very odd.

Thanks!

hmmm..... interesting "scratches chin" :lecture:

I just spoke to tech support at TracTech. They suggested doing what I have already done, which is put the thing on jack stands and try various tests with each side of the vehicle, in and out of 4wd. He said that unless it was "busted up inside", that the TrueTrac would not cause this. He said to lock the drive shaft, then turn each wheel and make sure the two front tires were rotating in opposite directions, which I believe I have done with various other tests. He said I would have a "chunky" movement and that it would not be a smooth rotation. I will try again tonight, but I don't believe I am going to find this to be the case.

I have the same problem with my jeep but I have a lock right in my jeep, and in 4 wheel drive it pulls right. I can explain the reason yours pulls to the left is because the shaft is shorter on the left side just like torque steer in a front wheel driv., Plus the caster angle should be less on the left side which makes a car "counter" the right pull on a road. Now for my case, I really cant explain why mine pulls to the right im thinking it is because the caster angle on mine is less on the right side. I would probably call it a normal condition as us technicians at Ford say.

Thanks for the feedback. Just a curious situation. It has not done this in the almost 3 years I have had the TrueTrac. I wondered if the bent centerlink (tire rod connecting rod or whatever the technical term is) courtesy of my last trail ride, might have anything to do with it. I pulled it straight with my winch and a snatch-block. The bend is on the same side. But, without the thing in 4WD, it tracks pretty much straight. Hmmmmm.....

rtbarton said:

Thanks for the feedback. Just a curious situation. It has not done this in the almost 3 years I have had the TrueTrac. I wondered if the bent centerlink (tire rod connecting rod or whatever the technical term is) courtesy of my last trail ride, might have anything to do with it. I pulled it straight with my winch and a snatch-block. The bend is on the same side. But, without the thing in 4WD, it tracks pretty much straight. Hmmmmm.....

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Well just an Idea but with the front axle pulling it would be adding forces to the axle/CA's ball joints and such that are not there while in 2WD. I know if my front end gets a bite on something in 4wd (and locked)it pulls like crazy...like one side of the edge of a dirt road or something. Maybe you have a suspension component that is worn and changing geometry while in 4wd. It sounds like a CA is shifting under torque to me, but that is just a stab in the dark. Hard to tell just jacking up the front and not being able to apply torque to the wheels.