Gear/bearing noise on deceleration

[KennyBob]

Tried searching for something pertaining to this and couldn’t find anything that sounds exactly right. So I thought I’d see what the collective knowledge of mud has to say.

I’ve got what sounds to me like a gear or bearing noise coming from what seems to be the t-case or transmission whenever I initially let off the gas and the truck decelerates. It’s momentary and I can prolong it a little by keeping on the gas a little bit and slowing the deceleration.

So I don’t have to blindly pull stuff apart and inspect bearings and gears, has anyone had a similar sound?

 

[leonard_nemoy]

I have had the exact same issue for 5 years and 80,000 miles. My cruiser mechanic diagnosed it as either a front t case output bearing or front differential input bearing. I wanted him to fix it when I got the rig 5 years ago but he convinced me to let it go until it got noticeably worse to save money. The old don't fix it if it ain't broke philosophy. He said he has seen multiple lifted cruisers go along time with the vibration and no issues. So far it hasn't got any worse.

 

[b16]

Sounds like what my U joints sounded like after my lift.

 

[KennyBob]

Interesting. I didn’t realize that was a sound I would hear after a lift. Always heard it was more a growling sound.

 

[NLXTACY]

Interesting. I didn’t realize that was a sound I would hear after a lift. Always heard it was more a growling sound.

If you did a 4” lift then it’s the driveshaft

 

[inkpot]

Sounds like what my U joints sounded like after my lift.

That's where I would look first. Grease ONE joint well, then test drive. If no change then grease bvb the other one and test drive again.

 

[KennyBob]

I have a 50mm lift on my relatively light 91. It netted me 3” to 3.5”.

I recently greased all of my u-joints. This has definitely come up since I did that.

I’ll take a look and see if they are still well greased.

 

[leonard_nemoy]

Mine is a 91 also and greasing/replacing u joints never helped mine

 

[KennyBob]

If it’s u-joints and there’s nothing to do but grease them then I’m fine with that. My concern was that it was something wearing/worn out in the t-case that needed replacement before it grenades itself.

 

[retrofive]

Mine was u-joints as well. Ended up replacing.

 

[koifish]

This the sound? Happened to me last year. I greased the driveshaft and knuckles. It's been 5k miles, so far so good.

 

[KennyBob]

I’m assuming pulling the front shaft would help me pinpoint which u-joints are the culprit. I think I remember something about the “broken-w” configuration of the front shaft making it susceptible to the noise.

 

[KennyBob]

This the sound? Happened to me last year. I greased the driveshaft and knuckles. It's been 5k miles, so far so good.

It’s definitely not that sound. It’s more of like a loose, worn skateboard bearing sound.

 

[renago]

I would not do 10 km with that noise ,how can you accept 5000 !
But we are all different .

 

[KennyBob]

I would not do 10 km with that noise ,how can you accept 5000 !
But we are all different .

He’s saying it’s been 5k since he greased everything I think.

 

[koifish]

He’s saying it’s been 5k since he greased everything I think.

Correct, hasn’t happened since greased everything. Horrible sound for sure!

 

[Jgunner]

It’s definitely not that sound. It’s more of like a loose, worn skateboard bearing sound.

I have the same noise. I have a 3” lift and caster plates. went new ujoints, didn’t fix. Dc shaft, didnt fix. Rebuilt front axle snd made sure there was tons of grease on bushings, didn’t fix. To me it sounds like a bearing in my t case, but it keeps going and not getting worse. I need to measure my angles of my pinion vs tcase. Ive just been too busy.

 

[KennyBob]

I have the same noise. I have a 3” lift and caster plates. went new ujoints, didn’t fix. Dc shaft, didnt fix. Rebuilt front axle snd made sure there was tons of grease on bushings, didn’t fix. To me it sounds like a bearing in my t case, but it keeps going and not getting worse. I need to measure my angles of my pinion vs tcase. Ive just been too busy.

Yes! Exactly. Sorry to say I’m glad you’ve spent the time and money to try to track that noise down. Suppose the next step is to crack open the t-case...

 

[Jgunner]

Yes! Exactly. Sorry to say I’m glad you’ve spent the time and money to try to track that noise down. Suppose the next step is to crack open the t-case...

Exactly where im at. I just need some coin for high/low gears for it!

 

[KennyBob]

Exactly where im at. I just need some coin for high/low gears for it!

I was thinking that or a part-time kit would be a good excuse to crack it open.