Rear axle whine, what do you think of this pattern? (1 Viewer)

[GarlicSnake]

Had some rear axle whine at 55mph. Removed the rear driveshaft and whine was gone so confirmed it’s the rear axle. Pulled the diff and checked backlash and pinion preload, all in spec. Then I ran a pattern. Coast looks good, drive is at the root. I’ve heard on high mileage gears to pay more attention to the coast side because it’s not worn. What do you think? I recently bought this LC with 240,000 miles so I don’t know the history.

 

[Tools R Us]

Often whine is from a pinion bearing dying.

 

[GarlicSnake]

Correction, pinion preload was not in spec. I was reading the specs wrong on the FSM. It has 0.4 NM total. I took the diff out and measured just the pinion and it has basically nothing. So the PO probably replaced the pinion seal and didn’t torque it back down properly. I’ll try getting the correct pinion preload and see if that fixes it. If not, I’ll replace the pinion bearings.

 

[Cruiserdrew]

If it's apart, you should just rebuild the differential. 240K is a lot of miles.

I don't see a lot of out of place wear on the ring gear, so hopefully it can be reused but even if you replace, it's just $200 more $$. IF you want to save some $$, the front diff probably has very little use and you could swap front to rear and use the rear as is.

 

[I Lean]

If it's apart, you should just rebuild the differential. 240K is a lot of miles.

I don't see a lot of out of place wear on the ring gear, so hopefully it can be reused but even if you replace, it's just $200 more $$. IF you want to save some $$, the front diff probably has very little use and you could swap front to rear and use the rear as is.

Since this is posted in the 80 section, I'll assume the OP is working with an 80....front and rear diffs are not interchangeable like they would be for your 40's and 60's.

 

[GarlicSnake]

Since this is posted in the 80 section, I'll assume the OP is working with an 80....front and rear diffs are not interchangeable like they would be for your 40's and 60's.

Correct, it’s a 1995 Landcruiser.

 

[GarlicSnake]

If it's apart, you should just rebuild the differential. 240K is a lot of miles.

I don't see a lot of out of place wear on the ring gear, so hopefully it can be reused but even if you replace, it's just $200 more $$. IF you want to save some $$, the front diff probably has very little use and you could swap front to rear and use the rear as is.

There’s a good chance I’ll be regearing it in a few years so for now I just want to fix the noise and prevent a failure when I’m out in some remote location.

 

[bigredmachine]

your contact pattern looks good, I would just try to adjust the pinion preload and when the noise gets worse than do a rebuild.
tighten the pinion nut a little bit at a time so you don't over torque.

 

[bigredmachine]

just out of curiosity did you find any of the original pattern test paint on the gear set? I pulled my rear to install a locker and was surprised to still find the paint from when it was originally assembled after 150,something miles and 25 years of driving

 

[GarlicSnake]

your contact pattern looks good, I would just try to adjust the pinion preload and when the noise gets worse than do a rebuild.
tighten the pinion nut a little bit at a time so you don't over torque.
View attachment 1935084

Thanks! I appreciate everyone’s input. I’ll post an update after I get it back together.

 

[GarlicSnake]

just out of curiosity did you find any of the original pattern test paint on the gear set? I pulled my rear to install a locker and was surprised to still find the paint from when it was originally assembled after 150,something miles and 25 years of driving

Yes I was able to see some faint orange paint in the root of a few teeth. You really think this could be the factory original pattern check? Pretty amazing if it is!

 

[inkpot]

Did you check the joints in the rear shaft? Sometimes a dose of fresh grease will quiet them down.

 

[Tools R Us]

Correction, pinion preload was not in spec. I was reading the specs wrong on the FSM. It has 0.4 NM total. I took the diff out and measured just the pinion and it has basically nothing. So the PO probably replaced the pinion seal and didn’t torque it back down properly. I’ll try getting the correct pinion preload and see if that fixes it. If not, I’ll replace the pinion bearings.

As they age, it's not uncommon for the preload to go way. When we have diffs out, reset it. If there is a bearing dying, resetting preload wont help. Replacing pinion bearings is pretty easy, as long as the same shims are kept in the same places, no gear setup needed. Press the new pinion bearings, races, reset preload, put the carrier in, set back lash and preload, good to go. Have seen several pinion bearings die, other than a full grenade, debris getting to them, have never seen a carrier bearing die, they turn at a quarter the speed.

 

[bigredmachine]

Yes I was able to see some faint orange paint in the root of a few teeth. You really think this could be the factory original pattern check? Pretty amazing if it is!

I think that was the same color on mine as well and I know that the diff didn't have any work done to it or even been out of the axle. I was really surprised it was still there after all that time

 

[GarlicSnake]

Got the pinion preload in spec and the noise is still there. I ordered a set of pinion bearings so I'll try replacing those next weekend. The Land Cruiser is awesome, but I'm finding that nobody carries parts for it locally.

 

[Tools R Us]

Cruiser Outfitters

 

[GarlicSnake]

Got the pinion bearings replaced today. The sound is nearly gone. If I really try and hit the throttle just right at 55 mph, I can hear a faint whine. I'm gonna call it good and just assume its some gear noise due to the mileage on the gear set.
Thanks everybody for your input.

But now I have a new problem. I'll start a new thread about the noise my diff lock actuator started making...