Noise from Rear

[GP59]

Hey mud,
I recently had my rear pinion seal replaced and a new companion flange installed at Land Cruiser Heaven.

About 100 miles later I started hearing a whirring noise from the rear while driving:
- noise increases with speed and does not adjust to transmission gears
- when shifting to neutral while at highway speed, the sound stays the same

Things I've inspected
- jacked up rear end and put t case in neutral.
- removed rotors and calipers from equation, put wheels back on and spun and no noticeable noise
- no play in wheel that would indicate rear wheel bearings
- driveshaft is solid going into rear diff. No side to side or in and out.
- using a stethoscope and turning driveshaft by hand I do hear som grinding they seems to be loudest at the rear diff but I can hear it faint from other spots along the axle as well.

Any ideas?

 

[Rhetoric]

Hey mud,
I recently had my rear pinion seal replaced and a new companion flange installed at Land Cruiser Heaven.

About 100 miles later I started hearing a whirring noise from the rear while driving:
- noise increases with speed and does not adjust to transmission gears
- when shifting to neutral while at highway speed, the sound stays the same

Things I've inspected
- jacked up rear end and put t case in neutral.
- removed rotors and calipers from equation, put wheels back on and spun and no noticeable noise
- no play in wheel that would indicate rear wheel bearings
- driveshaft is solid going into rear diff. No side to side or in and out.
- using a stethoscope and turning driveshaft by hand I do hear som grinding they seems to be loudest at the rear diff but I can hear it faint from other spots along the axle as well.

Any ideas?

I am going to assume you had a leaking pinion seal? Did the person who worked on the rig note the condition of the gear lube they drained out when changing the seal? Did they verify how much lube was left vs what should be there if there was a leak?

 

[GP59]

I am going to assume you had a leaking pinion seal? Did the person who worked on the rig note the condition of the gear lube they drained out when changing the seal? Did they verify how much lube was left vs what should be there if there was a leak?

Correct leaking pinion seal. I confirmed level was not very low before taking it to shop. I dont believe the level ever got very low. I will have to see if they recorded how much came out.

 

[SteveH]

Go slowly. It's easy to misdiagnose rear axle sounds. I would lean toward wheel bearings, if the sound is no different under load or no-load - but some what you've tested might rule that out.

Being super safe, or having a shop with a lift do this - support the entire rear end, put it in gear, and listen by each rear wheel as the wheels turn in free air at a fairly slow speed. You don't have to have the speedo at 60 on the lift for this test - idling in 1st gear is usually enough speed.

 

[GP59]

Go slowly. It's easy to misdiagnose rear axle sounds. I would lean toward wheel bearings, if the sound is no different under load or no-load - but some what you've tested might rule that out.

Being super safe, or having a shop with a lift do this - support the entire rear end, put it in gear, and listen by each rear wheel as the wheels turn in free air at a fairly slow speed. You don't have to have the speedo at 60 on the lift for this test - idling in 1st gear is usually enough speed.

Wouldn't I need to have the front wheels up too?

 

[SteveH]

Oops yes - AWD. I've only done this on part-time 4WD trucks until now. Good point!

 

[Rhetoric]

Agree with Steve on taking your time in the diagnosis. Lots of bits that it could be, so be methodical about it.

 

[GP59]

Drained the rear diff. Looks like a lot of shavings but not chunks?

 

[Rhetoric]

Is that only with 100 miles on the gear lube?

What color / consistency is the gear lube?

In my pic below, the right shows brand new gear lube. The left shows gear lube with 3k miles on it that I drained after hearing a similar noise to yours in my front diff. I had a leaking pinion seal that did not get addressed in time…

 

[GP59]

Had a different sho inspect. They are telling me the preload should have been set at 12 or 1 o'clock, and it was set to 3 o'clock according to what they found and what is in the picture.

Not sure I fully understand.