Differential Whine

[NikeCheck246]

I am trying to figure out a whine (coming from front) on the P38. Comes in after it is warmed up, highway, maybe 25% load. Can also hear it on takeoff and slowing to a stop, mostly below 10mph but I believe it has started increasing speed. Checked wheel bearings...no play whatsoever. Drained fluid in front diff, no metal, very clear. U-joints look ok, can't find any play.

My thought is front diff. Can a diff go bad with no metal in the gear oil?

 

[Jake1996D1]

I am trying to figure out a whine (coming from front) on the P38. Comes in after it is warmed up, highway, maybe 25% load. Can also hear it on takeoff and slowing to a stop, mostly below 10mph but I believe it has started increasing speed. Checked wheel bearings...no play whatsoever. Drained fluid in front diff, no metal, very clear. U-joints look ok, can't find any play.

My thought is front diff. Can a diff go bad with no metal in the gear oil?

yea bearings can go bad without losing a ton of metal which is what you're probably hearing. Its probably pinion bearings on there way out.

 

[NikeCheck246]

yea bearings can go bad without losing a ton of metal which is what you're probably hearing. Its probably pinion bearings on there way out.

That is my thought, just wanted to make sure Jake's thoughts were inline with mine.




In all seriousness, I just want to see what thoughts everyone has.

 

[Jake1996D1]

That is my thought, just wanted to make sure Jake's thoughts were inline with mine.




In all seriousness, I just want to see what thoughts everyone has.

If you think its the diff, pull it run a contact pattern, check backlash, inspect bearings, and you'll be able to see why.

 

[NikeCheck246]

I hate to pull the damn thing just to put it back in. If it was my Disco, I would be all over it, but the P38 is a nightmare.

 

[Jake1996D1]

I hate to pull the damn thing just to put it back in. If it was my Disco, I would be all over it, but the P38 is a nightmare.

Yea I hear ya. Only one way to find out whats going on in there. Or just let nature take it's course and you'll be certain it's worth pulling in a couple months

 

[NikeCheck246]

Yea I hear ya. Only one way to find out whats going on in there. Or just let nature take it's course and you'll be certain it's worth pulling in a couple months

I have been thinking alot about nature and it's course...especially what would happen if the front diff locked up. My thoughts are to replace it, and worst comes to worst, I will have a good spare diff for the rear.

 

[76FJ55]

Locker/ limited slip the rear, move the rear to the front and retain the front as a spare.

 

[NikeCheck246]

Locker/ limited slip the rear, move the rear to the front and retain the front as a spare.

I feel like that would be unneeded for a strictly street vehicle.

 

[Jake1996D1]

I feel like that would be unneeded for a strictly street racing vehicle.

I think it would actually work out great for your street racing P38

 

[NikeCheck246]

I think it would actually work out great for your street racing P38

Danger to manifold

 

[ccollins]

I have been thinking alot about nature and it's course...especially what would happen if the front diff locked up. My thoughts are to replace it, and worst comes to worst, I will have a good spare diff for the rear.

I had my front diff lock up while driving, not pretty. I would take the time to pull it and inspect it, you have the tools and a lift!

 

[Gordo]

My P38 has had gear whine since Ive owned it. 5 yrs or so. Not real loud but its there.Mines from the rear I believe. I live with it. Id check the wheel bearings first if I were you. If you really think its the diff, consider a used one and just change it while you are in there. By the time you replace the bearings/pinion and carrier and pay to get it set up, it will probably be cheaper. Even with new bearings it may still whine if the ring and pinion are the culprit.