Hi all,
Ive got a 1998 XJ with a budget lift of roughly 3 inches. Grand cherokee springs and some coil spring spacers give the lift up front. AAL up back.
Tyres are 235/75/15 on factory rims. Diff fluid, t-case fluid and all front u-joints are in good shape. When Im in 2wd everything is totally fine.
When I shift the t-case into 4wd (hi or lo), a low whine starts up front. Driving in a straight line is fine (apart from the whine), but as soon as I try to steer (worse when steering to the right), theres a loud groaning sound from up front and the jeep starts to shudder. I know a bit of tire hop is to be expected in 4wd, but this is something else. The front end starts bouncing around and the engine starts to labour as if its about to stall out. At the same time the t-case lever starts rattling around. The jeep slows right down to a crawl.. stepping on the gas only makes it groan louder and lurch around more up front.
Ive checked and replaced all fluids-inspected the diff interior - replaced all bad u-joints-checked all mounts for the engine and transmision/t-case. A couple of my steering linkage bushes are a little bit worn, but nothing major. Could it be a major steering fault?.. Ive no clue - all opinions welcome!.

 

Sounds like the spiders in the diff are seized. You are OK until you lock in that right axle when in 4WD.

If in 2WD you applied vacuum to the right port on the actuator, jacked up I bet both front wheels will be locked together at the diff. when you turn one.

 

Thanks DFlinstone.
What could I do about that.. would stripping down and rebuilding the diff gears sort it, or do you think it capoot?.. replacement parts required.. hope not. Appreciate the response - it gives me another angle to look into.

 

I would check to make sure you have the same gear ratio in your axles. Someone previous might have swapped one axle out and now you have miss matched ratios.

Also your 98 won't have a vacuum disconnect.

 

Thanks veeb0rg - didnt even consider that - appreciate it!

 

Would locking the front diff help or make matters worse?. Sorry if this is a dumb question but Im new to the home mechanic thing - loving it!, but still learning. If I lock it up would it solve ratio issues?. Ive just spent a fair bit of money and time replacing several u-joints, bushes and engine mounts, and would like to resolve this as easily and cheaply as possible

 

Thanks VeebOrg. Motori, when in 4WD your fronts and rears are locked together and all need to go the same speed. A different ratio in a differential, or even ONE wheel that's a different size will cause it to bind up. DON'T DO THAT! Not good on gravel and REALLY not good on asphalt. Something will have to give when your moving, and could be something $$$. Your tires ARE all the same?

 

I had this same thing happen on a Yota. Check your front and rear gear ratios. They probably don't match.

 

How is your power steering fluid level? Low?

 

power steering fluid is fine.. all tyres and wheels are the same size. Steering box, pitman arm etc all look in fairly good order. Different front and rear gear ratios are starting to seem like a possible cause. I will look into that and give an update - let you know what I find!. Thanks guys - appreciate it.

 

Sounds like locked spiders or wrong gear ratio. I would go with the locked spiders since it only happens when turning.