2nd opinion on my diff whine
couple of suggestions
did they reset pinion height/preload??, pinion height on a P38 can only be set to the bearing face, the common method of measuring to the pinion face 'cannot be used', pinion face is not machined!. So how was the pinion height set.??
If the Trans shop is used to re-building hypoid diffs then it is possible they tried to use the same method on your spiral bevel gear. Set up adjustments are different for the two types!! With a spiral bevel you adjust the backlash to move the pattern from toe to heel, with a hypoid you move the pinion to move the pattern from toe to heel. Can cause confusion!
One of the biggest problems I have found with these P38 diffs is too much pinion pre-load (even from factory), I realise that because of the design with the two bearings close together pre-load is important but too much causes excessive heat build up and premature pinion brg failure.
Hope this helps
Regards Ian Ashcroft
2nd opinion on my diff whine
Hi JC I agree unless there is a pinion brg issue, leave it alone, the only variable then is the backlash, if replaced as was and it was quiet it should still be quiet. Having said that we still get caught out, sometimes, even using blue there can be problems.
It is not unusual for a 'P38' diff in the back of a 110 to fail, usually teeth strip off the crownwheel
The 'thin' crownwheel is subject to debate, I have never seen a crown wheel split ,yet, not saying they won't, just never seen one. I have seen many with the teeth stripped off.
With regards to matl spec, we did quite a lot of research on materials recently in prep for our new range of C&P. Whilst Rover was better than all aftermarket (including ours) we upgraded our spec to exceed Rover, time only will tell.
I think the Rover P38 diff is just not up to the job in the rear axle of a 110, whether it is , tooth profile, crown wheel thickness, or material spec I really don't know.
We have opted to change tooth profile, thicker teeth, and up the mat'l spec on the new range just launched. Could be we also need to look at a replacement set for the P38??.
Regards Ian Ashcroft