Bearing noise on decel

Rob F · Jan 1, 2017

Hey all. I need some opinions. I have an 03 Sahara, NV3550 5 spd and 231 J t-case. I have developed over the last 2 months a very loud bearing noise when I let off throttle, in all gears. Even coasting in neutral it is there. If I throw the t-case in neutral when coasting, it goes away. Unfortunately that doesn't mean much. I have a 2" spacer lift that did cause some driveline vibes, installed about 10 months ago. I am thinking that driveline vibes mean damage somewhere, and maybe it took this long to wear out a bearing in the t-case. Any thoughts before I start all the expensive trial and error crap? Thanks.

Chris · Jan 1, 2017

Rob F said:
Hey all. I need some opinions. I have an 03 Sahara, NV3550 5 spd and 231 J t-case. I have developed over the last 2 months a very loud bearing noise when I let off throttle, in all gears. Even coasting in neutral it is there. If I throw the t-case in neutral when coasting, it goes away. Unfortunately that doesn't mean much. I have a 2" spacer lift that did cause some driveline vibes, installed about 10 months ago. I am thinking that driveline vibes mean damage somewhere, and maybe it took this long to wear out a bearing in the t-case. Any thoughts before I start all the expensive trial and error crap? Thanks.

It happens on deceleration but not on acceleration?

First thing I would do is get underneath the vehicle and look at the driveshafts to see if they're rubbing on any part of the transfer case skid plate (or if you can notice any wear marks in those areas at all).

Jerry Bransford · Jan 1, 2017

Noise/whine when decelerating is often caused by a bad pinion bearing. Drivetrain vibrations can definitely take out pinion bearings and seals which is why I always say you can't just live with vibrations... they'll eventually take out something.

http://fuelandfriction.com/weekend-warrior/understanding-rear-differential-noise/

Chris · Jan 1, 2017

Ahhh, Jerry makes a good point. It more than likely is your pinion bearing. Especially since you've been having drivetrain vibrations.

Rob F · Jan 1, 2017

Chris said:
It happens on deceleration but not on acceleration?

First thing I would do is get underneath the vehicle and look at the driveshafts to see if they're rubbing on any part of the transfer case skid plate (or if you can notice any wear marks in those areas at all).

Nothing there. All good.

Rob F · Jan 1, 2017

Jerry Bransford said:
Noise/whine when decelerating is often caused by a bad pinion bearing. Drivetrain vibrations can definitely take out pinion bearings and seals which is why I always say you can't just live with vibrations... they'll eventually take out something.

http://fuelandfriction.com/weekend-warrior/understanding-rear-differential-noise/

I have had pinion bearing issues in other trucks. It's not that noise. It is a very loud scratchy bearing noise. It is hard to isolate it.

Chris · Jan 1, 2017

Rob F said:
I have had pinion bearing issues in other trucks. It's not that noise. It is a very loud scratchy bearing noise. It is hard to isolate it.

I wouldn't be 100% certain just based off the noise / symptom you've had with other trucks. Bearings can make that noise (loud and scratchy), and it certainly stands to reason since those vibrations you're experiencing are harsh on the pinion bearings.

Rob F · Jan 1, 2017

Chris said:
I wouldn't be 100% certain just based off the noise / symptom you've had with other trucks. Bearings can make that noise (loud and scratchy), and it certainly stands to reason since those vibrations you're experiencing are harsh on the pinion bearings.

Thanks Chris. I'll have it on a hoist tuesday so hopefully I can figure to out. Happy New Years!

Chris · Jan 1, 2017

Rob F said:
Thanks Chris. I'll have it on a hoist tuesday so hopefully I can figure to out. Happy New Years!

Let us know what you find. I'll be surprised if it isn't the pinion bearing. But once you have it on a hoist I think it should be pretty obvious. You could put it in neutral and spin the tires while it's up on the hoist to see if it makes the noise. That would make it easy to track down.

Stinger · Jan 2, 2017

I also would suspect a pinion bearing-——-until you said it went away when you shoved the TC into neutral.
I would suspect the TC. I would attempted to isolate by first removing the front driveshaft and test it. Then reinstall it and try with the rear shaft removed.
Please tell us what you find.

Rob F · Jan 5, 2017

Stinger said:
I also would suspect a pinion bearing-——-until you said it went away when you shoved the TC into neutral.
I would suspect the TC. I would attempted to isolate by first removing the front driveshaft and test it. Then reinstall it and try with the rear shaft removed.
Please tell us what you find.

You won't believe what we found. I figured we would start with the pinion bearing first. The fluid was black and only about 5 months old. The bearing wasn't great but check this. While the Jeep was in the shop, I had the front ball joints in the back seat (drivers side was loose), so I said do it. When the guys got to the ball joint, it popped right out and so did a makeshift sleeve around it. It would seem that a previous owner replaced the joint before, and probably didn't have a press, or didn't know what to do. They honed out the hole where the joint goes, and made it too big, so they cut a sleeve around the top ball joint so it would fit. Now the new joint just falls into place. So guess what? Now I need a new axle housing. So far, 2017 sucks.

Stinger · Jan 5, 2017

Rob F said:
You won't believe what we found. I figured we would start with the pinion bearing first. The fluid was black and only about 5 months old. The bearing wasn't great but check this. While the Jeep was in the shop, I had the front ball joints in the back seat (drivers side was loose), so I said do it. When the guys got to the ball joint, it popped right out and so did a makeshift sleeve around it. It would seem that a previous owner replaced the joint before, and probably didn't have a press, or didn't know what to do. They honed out the hole where the joint goes, and made it too big, so they cut a sleeve around the top ball joint so it would fit. Now the new joint just falls into place. So guess what? Now I need a new axle housing. So far, 2017 sucks.

Now that just sucks! Would never have suspected that !

Chris · Jan 5, 2017

Rob F said:
You won't believe what we found. I figured we would start with the pinion bearing first. The fluid was black and only about 5 months old. The bearing wasn't great but check this. While the Jeep was in the shop, I had the front ball joints in the back seat (drivers side was loose), so I said do it. When the guys got to the ball joint, it popped right out and so did a makeshift sleeve around it. It would seem that a previous owner replaced the joint before, and probably didn't have a press, or didn't know what to do. They honed out the hole where the joint goes, and made it too big, so they cut a sleeve around the top ball joint so it would fit. Now the new joint just falls into place. So guess what? Now I need a new axle housing. So far, 2017 sucks.

Holy cow... Now that is what I call jury rigging.

You don't need a new axle housing though. @Jerry Bransford pointed this out before to someone else, but you should be able to get a new inner C (or whatever the technical term for it is) for the axle and have it welded on in place of the old one. I'll let Jerry correct me if I am wrong about that, but I don't think I am.

Jerry Bransford · Jan 5, 2017

Exactly. Have a 4x4 shop locate a junker Dana 30 axle and have them remove its inner-C and weld it on in place of your damaged inner-C.

Chris · Jan 5, 2017

Yep, that's it. No need to replace the entire axle housing as long as you can find a competent shop and another inner-C!

Rob F · Jan 7, 2017

It's not quite that simple, but it was a thought. I'm replacing all the control arms and front end stuff anyhow and lift. I've got a great Jeep Parts guy local and he has a complete housing, cheap. Since I'm unhooking everything anyway, it won't be a big deal.But I am seriously pissed about this. I have been back and forth from Toronto to Cincinnati while my son has been in hospital for 4 1/2 months. Not to mention my kids riding in the Jeep all the time before.

Chris · Jan 7, 2017

If he's got a cheap axle housing then you might as well.

Rob F · Feb 16, 2017

Hey guys. I just wanted to give a little update and thank all those who pitched in with advice. I went ahead and installed a Zone 4" suspension w/Nitro shocks and steering stabilizer. I also bought a SYE and double cardan driveshaft from Adams Driveshaft. Really nice stuff. I also swapped out my front axle housing and put my old 3.73 gears in. All new bearing and seals. Then I did the ball joints (remember my previous axle was honed out and the BJ's just fell in and out). Rubicon Express adjustable track bar. Freedom Offroad adjustable rear upper control arms and did the rear pinion bearing and seals. All new calipers, rotors and pads, e-brake shoes and kit. I did some LED headlights, 4" round LED tails, 2" reverse LED's relocated to the rear bumper and then license plate bolt lights, which I relocated under the spare on the rear. Smittybilt front bumper. I got a lot of stuff if not most, from Amazon and eBay, while I was in Cincinnati for my son's bone marrow transplant. I got it all back to London, Ontario, Canada with no issues and a friend helped me install everything at his shop. Thank goodness for that. After all this, I still have the nasty bearing noise, but it's a bad release bearing, which will be done next week, as well as a polyurethane tranny mount. Thinking about some 33" Deegan 38's. Phew. Done. Here's a couple pics. Thanks guys.