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Diff Bearing

Posted: Fri Sep 09, 2011 11:14 pm
by David53
Well, after replacing the uni joints and having the propshaft balanced (the new bearings threw it right out and it vibrated badly), I now realise the original wup wup wup noise is coming from a loose front bearing on the diff. Unfortunately, having the older style split rear axle means replacing this entails removing the entire rear axle from the car.....sigh....Any MM owners have any experience of this?

Re: Diff Bearing

Posted: Fri Sep 09, 2011 11:27 pm
by mike.perry
Read the instructions in the workshop manual then leave it alone :(
Have you tried tightening the pinion nut?

Re: Diff Bearing

Posted: Sat Sep 10, 2011 12:05 am
by David53
That bad eh Mike? Which nut is the pinion nut? (not near the car at the moment to look).

Re: Diff Bearing

Posted: Sat Sep 10, 2011 12:14 am
by bmcecosse
The big one - hidden under the prop shaft flange.

Re: Diff Bearing

Posted: Sat Sep 10, 2011 1:46 am
by David53
Thanks Roy. A box spanner job?

Re: Diff Bearing

Posted: Sat Sep 10, 2011 1:59 am
by David53
I'm assuming No:26 in this diagram - Looks like it's inside the flange, no need to remove the flange....Just tighten as hard as I can?

Image

Re: Diff Bearing

Posted: Sat Sep 10, 2011 8:26 am
by bmcecosse
Worth a try!

Re: Diff Bearing

Posted: Sat Sep 10, 2011 9:50 am
by mike.perry
That's the one. If there is any sign of oil drips then you can change the oil seal at the same time, undo nut, pull off propshaft flange, remove oil seal

Re: Diff Bearing

Posted: Sat Sep 10, 2011 10:16 am
by David53
Thanks Mike. No oil drips so seal must be ok. Will give it a jolly good tighten before I refit the propshaft.

Re: Diff Bearing

Posted: Sun Sep 11, 2011 2:58 am
by David53
Tried to tighten but clearly there was no slack there as my strongest efforts only resulted in the back wheels straining to go forward, pushing past the handbrake and moving.

I refitted the shaft and it has made a huge difference (see seperate post). I still have a slight "wup wup wup" noise, especially at low revs in top gear, going up a slight incline etc. It must be the diff as it does increase a little as the oil heats up and thins. Would there be a problem in increasing the viscosity of the oil? Currently using 80/90. What if I used a 85-140?

Re: Diff Bearing

Posted: Sun Sep 11, 2011 9:03 am
by MarkyB
What if I used a 85-140?
It would increase drag from the diff and sap a little power, not a good idea given how much you have to play with :)

Re: Diff Bearing

Posted: Sun Sep 11, 2011 11:57 am
by bmcecosse
Just turn the wireless up.........

Re: Diff Bearing

Posted: Sun Sep 11, 2011 12:10 pm
by David53
A wireless??? My car has none of those new fangled inventions!