Troublshooting Grinding Noise

I'm sure there are other threads about this, but I need to make this one specific to my Cherokee.

Right now I have a 99 Cherokee SE/Dana 30 high pinion/Chrysler 8.25/3.55 gears/231 transfer case/auto/RE 4.5 superflex/custom rear driveshaft with a SYE/and 31" BFG MT's.

Back when it was stock, I don't really remember having these problems, but I'm almost sure I didn't. Ever since I lifted it, I've been having trouble shifting out of 4WD and a low-level grinding noise on acceleration.

I started out with just the lift and the t-case drop kit. Then I got the SYE and rear driveshaft. The grinding was quite at first and got worse over the months. I removed the t-case drop kit and replaced the driveline with 3 different ones, thinking all of them can't be bad. Still got the noise. Replaced the t-case with another one with similar mileage. Still got the noise. Maybe it's a coincidence, but as the grinding got louder and deeper, it got harder and harder for my t-case to disengage from 4hi. When I jacked both axles up on jack stands and put it in 4hi and spun the tires, I couldn't really hear it on acceleration but did hear something coming from the t-case area.

So now I'm down to the front differential or something with the lift affecting the front angle of the driveshaft. What else am I maybe missing? Thanks for reading.eace:

Who's SYE kit?Also are you getting the grinding in 2WD?

maybe a bad cv joint?

I had a constant rotational grinding noise after my SYE also. I tried 2 different driveshafts from the junk yard, both of them were noisy. I was using stock front driveshafts in the rear since they had cv joints and slip in the middle. Turns out those cv joints cannot be greased. Not even the u-joints. It wasn't until I bought my new Tattons driveshafts that the grinding sound went away completely. The cv joints are 100% greasable.

What sort of custom rear driveshaft are you running?

I used the wack-and-tap RE SYE. And I'm only getting the grinding in 4HI and 4LO. 2WD is fine. After I had the jeep jacked up, I went under and listened to where it was coming from and it sounded like the front end of the t-case.

I'd hate to think that 3 driveshafts and 2 t-cases all did the same thing. I'm thinking it has to be something else.

I don't think it's the CV joint because I just got a new cv joint on my original driveline.


One more thing, one day I took the front driveshaft off and drove around in 4HI-I got no noise.

checked your hubs? can make a similar sound.
checked front pinion? roasted bearings can make that sound.
pulled the front diff cover and checked fluid and backlash/side to side case play? something out of spec there can indicate roasted diff bearings.

if you get no noise with no front shaft, the front axle would be what i looked at first - any parts that are powered in 4wd. good luck.

XJ Fever said:

I'd hate to think that 3 drive shafts and 2 t-cases all did the same thing. I'm thinking it has to be something else.

I don't think it's the CV joint because I just got a new cv joint on my original driveline.

One more thing, one day I took the front drive shaft off and drove around in 4HI-I got no noise.

Click to expand...

Clarify your post. 1)Are you still using the original front drive shaft ? 2)Have replaced anything else on the front drive shaft ? 3)Have installed a different front drive shaft and checked for noises ? 4) You wrote the CV is new , did you replace the centering ball assembly also ?

Since you have no noises with the front drive shaft off, 4) have you inspected the front diff ?

Worn slip yoke splines can make noises.

1998xj1985 said:

checked your hubs? can make a similar sound.
checked front pinion? roasted bearings can make that sound.
pulled the front diff cover and checked fluid and backlash/side to side case play? something out of spec there can indicate roasted diff bearings.

if you get no noise with no front shaft, the front axle would be what i looked at first - any parts that are powered in 4wd. good luck.

Click to expand...

Actually hubs are next on my list to replace, I was told they were worn, plus I can feel the sloppiness. The front pinion, not sure how to check that. And the I need to pull the diff cover off and check that soon. So, all that is on my list.

Tim_MN said:

Clarify your post. 1)Are you still using the original front drive shaft ? 2)Have replaced anything else on the front drive shaft ? 3)Have installed a different front drive shaft and checked for noises ? 4) You wrote the CV is new , did you replace the centering ball assembly also ?

Since you have no noises with the front drive shaft off, 4) have you inspected the front diff ?

Worn slip yoke splines can make noises.

Click to expand...

Right now, yes, I am using my original. I tried a couple other ones and they still made the same sound. So I took my original to a shop and had him look it over. He mentioned that the shaft probably was going bad. So instead of replacing I just had him replacing the joint with a new grease-able one(got some advice for that from a local jeep guy). I'm not sure one the centering ball assembly. Where is that located?

hubs are the likely culprit per your description.

check the pinion for sloppiness. it should not be able to wiggle in and out or side to side.

still though, hubs will most likely fix it. don't spend any more money until you have fixed things that you know are busted.

But if it were the hubs, wouldn't it make those noises during 2WD too? It makes no noises at all it 2WD.

XJ Fever said:

Actually hubs are next on my list to replace, I was told they were worn, plus I can feel the sloppiness.


I'm not sure one the centering ball assembly. Where is that located?

Click to expand...

The CV joint is 2 u-joints and a centering ball. You said the guy replaced just one u-joint ? The Tcase end u-joint ?

Next question, why are you installing multiple drive shafts and transfer cases to deal with a vague noise when you know your hubs are bad ? What if you replace the hubs and the noise goes away ?

I not trying to be an a$$, I just don't see the logic of throwing parts at a Jeep without discovering the root cause of a symptom or problem with a logical diagnostic process.

hub might be a little bad and worn to the point where power transmitted through them makes them grind? don't know. you said your hubs were worn. regardless of whether or not that fixes the problem, they need to get changed out because the vehicle is dangerous to drive with blown hubs

Tim_MN said:

The CV joint is 2 u-joints and a centering ball. You said the guy replaced just one u-joint ? The Tcase end u-joint ?

Next question, why are you installing multiple drive shafts and transfer cases to deal with a vague noise when you know your hubs are bad ? What if you replace the hubs and the noise goes away ?

I not trying to be an a$$, I just don't see the logic of throwing parts at a Jeep without discovering the root cause of a symptom or problem with a logical diagnostic process.

Click to expand...

I'm not sure if you can see everything but this is what he replaced.
lookint at t-case

looking towards axle.


I spent 30 on one driveshaft and 0 on the other. I had the time to put them on, so I tried it. The hubs are like 200 a piece. I figured 30 bucks was better then 200. The t-case was also free. More like a trade. So I tried that. I found out my hubs are worn AFTER all of this. Midas actually said they were bad, so they might just be trying to get me to spend money.

rockauto.com 90 a piece + shipping

if you're lucky, they should be a 20-30 min job/side to replace

XJFever said:

one more thing, one day I took the front driveshaft off and drove around in 4HI-I got no noise.

Click to expand...

That would really sound like a T-case chain,tear it apart,they are easy/cheap to redo! It could also be something as simple/cheap as fork pads.

Well, I got a free set of hubs from another jeep and put them on. It still grinds. I got them from a shop, the guy said they were good, otherwise he wouldn't have kept them.

I figure if I replace parts with other used parts, either the problem is fixed, gets worse, or gets better. It stayed the same so I figured thats not the problem. Although, I think it did fix my problem I was having when making tight turns. So what's next?

Edit: Oh I forgot, pull the front diff cover and check for anything unusual. What should I look for? The fluid was changed less than around 5-10k miles ago, so it's still fairly new

Update:

I pulled the cover and noticed the oil oozing like it was almost frozen(it's about 10 below here).

The oil was pretty dark but no metal shavings I could see:


So then I pulled both shafts out to look at the bearings and this is what I found.

Drivers side looked ok:


Passenger didn't:



So I replaced both of them, put everything back together, put new oil in, and took it for a drive. Maybe it's just stuck in my head, but I still heard some noise up there.

What would u guys check next?

ttt

no one knows huh?

So, the noise is worse in the sub-zero degree weather. Could the front driveshaft angle be an issue?