P38 Gearbox whine?

Hello all,

Once again I call upon the expertise in this forum.

The auto box in my 1999 p38 2.5 dse started to whine. I recently did an oil change (about 1300 miles ago). But on the way to work the other day the gearbox or transfer box started whining. Usually while decelerating and sometime on gear changes. Initially it was whining constantly in top gear while cruising too. But that seems to have stopped now.

Over the last couple of days I've noticed a slight change, it really only does it while decelerating. She's also holding first gear a long time until I hit about 3000 rpm with moderate acceleration. The whine doesn't seem to be related to road speed but engine speed. If I put he car into neutral while decelerating the noise stops. And in low range it has the same symptoms.

I've checked the oil level and all is well although a leak does seem to have developed in the last 1300 miles.

I was hoping someone could help me to look in the right place for the fault. Is it a problem with the gearbox, transfer box, diff or many be a bearing?

Cheer ole

Check the pinion bearings on the rear differential. Sounds like that could be your problem.

Thanks for the reply wammers. Can I check that without taking off the rear prop? How?

olesmokie said:

Thanks for the reply wammers. Can I check that without taking off the rear prop? How?

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Get under it and check for up down, sideways movement in the flange. There should be non at all. Noise on over run is classic of diff pinion bearing wear. Noise comes when crown wheel is driving pinion off throttle, worn bearings allow angle to change pinion to crown wheel. That is when you get the noise. If it is whining on throttle it really is getting ready to do something about it.

There doesn't seem to be any movement in the rear prop at the diff. The front has a tiny bit but I could be feeling some play in the uj.

Would that also explain it hanging on to first gear for so long?

olesmokie said:

Would that also explain it hanging on to first gear for so long?

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No not hardly how could it? Stick some Lucas in it, a sticky valve would do that.

olesmokie said:

There doesn't seem to be any movement in the rear prop at the diff. The front has a tiny bit but I could be feeling some play in the uj.

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Should not be any play in the UJ sort that out. You are looking for up/down sideways movement in the flange.

Just an update. Play in uj sorted. But the whine problem seem to be the gearbox or transfer. Hard to tell which even with a stethoscope while the car is running jacked up over a pit. So thinking of getting a secondhand 4hp24. Just gotta do some searching to find exactly what I need to get to do the swap.

Cheers for all ya help so far

olesmokie said:

Just an update. Play in uj sorted. But the whine problem seem to be the gearbox or transfer. Hard to tell which even with a stethoscope while the car is running jacked up over a pit. So thinking of getting a secondhand 4hp24. Just gotta do some searching to find exactly what I need to get to do the swap.

Cheers for all ya help so far

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Just the box from a P38, the 065 version is better. You need the bell housing from your old box and maybe the oil pump, otherwise it's a straight swap Good idea to fit a recon torque convertor while you are at it.