Broken Diff Pinion Bearing (Z3M)

[Lee]

Not what I always do on a friday evening. I haven't driven my girl in a week so I took her into work. Noticed a little vibration in the rear when i lift off the throttle.

What i found was a knackered Input shaft bearing (aka pinion bearing) bad as it sounds its not the end of the world. The LSD is intact need to replace the bearing prop shaft side.

Time to get my hands dirty again.

 

[Lee]

View: http://youtu.be/JPsb_YQc44g

 

[t-tony]

How do you go about setting the pre-load on a Z Lee?

Tony.

 

[Lee]

Unless i can find out what pre-load is needed i will have to seek professional advice. Luckily i have a transmission place near me.

 

[t-tony]

I will see if we have any data at work then Lee.

Tony.

 

[Lee]

Removed the Diff this morning, took about 50mins. Was quite a fiddly job because the bolts holding the diff are on top of the subframe.

On closer inspection it looks like its lost the preload on the pinion bearing. Lucky i have caught it now before it does any damage. I will drop it off to a company during the week.

Lee

 

[t-tony]

Hi Lee, no info on Carweb or Autodata for Diff pre load. Too specialised a job I expect.

Tony.

 

[Lee]

I have dropped the Diff off to a specialist in Basingstoke, Luckily there is a lot of company's that deal with diff's. Parts for the diff's are very hard to find but I found two websites that sell everything (Clutch plates, Crowns, Bolts, Bearings)

www.Driveandtraction.co.uk

www.bimmerdiffs.com

The guy has quoted me £240 all in for the rebuild.

Lee

 

[Aceman]

Interesting read Lee something else to look forward to with mine.

I have mine in bits at the moment with the induction side of the engine stripped down due to a inconsistant idle which I think was due to the throttle bodies have a gum line build up so cleaned them all and will be reassembling it all tonight. I am also contemplating having the vanos done by Mr Vanos who have quoted me £825 all in including retiming of the cams and valve shims plus they come to me which I didn't think was too bad. I have been reading up on doing it myself but the more I read about the more a I talk myself out of it so think I am going to dig deep and get it done.

 

[Lee]

Yeah it's another big job I can tick off. The Vanos is the last item. I will go down the same route for that reason. Mines on it's second Vanos (Bmw Built) and has had a change of seals a couple of years ago.

Lee

 

[Lee]

Update: Collected the Diff on Friday and fitted in the evening with the help of Gaz, Quite fiddly getting everything lined up but a good 2 hours later I was out test driving her.

First impression: The power delivery seems more instant you almost have to be a little more careful bringing up the clutch. But most important of all the CLUNK and gone entirely. She does whine a little but nothing to be worried about.

For £240 I got all the bearings replaced and new seals, he also checked the LSD was healthy. He turned this around in 3 days for me.

Case closed

 

[Brian H]

On closer inspection it looks like its lost the preload on the pinion bearing.

Was there any mention of this from the specialist @Lee?

 

[Lee]

Was there any mention of this from the specialist @Lee?

Yeah it had starting losing its preload due to wear in the taper bearings.