Diff back plate

[Derick Mills]

Were you running the stock bush on this?
What mileage and what engine?

Can materials like this suffer from ‘casting’ defect when made that causes these problems?
Mine is 22yrs old with 135k miles, the last 5yrs with poly bush and it hasn’t cracked yet - gets used properly too.

When I was looking at uprated diffs I spoke to a place that builds diffs for race and rally BMW cars and they don’t worry about the single ear diff mount - his experience was if they haven’t broken yet they won’t so he has race and rally cars using that design. Seems to be something in the build process as likeThe boot for issue- some cars rip the boot floor out with light use and others never do even with ‘proper’ usage?

My Z has 115,000 1997 2.8 and it had a stock bush in. I have had the car 2 years total rebuild needed. Before I had it the Z had been stood in a field for a couple of years, so as you can imagine a roadster it was soaking inside both seat motors were seized adjusting worm wheels were solid etc, all the work has now been completed except for the bushes and when they are done it's off for a respray and new top then I'm off to the rallies with you lot. The Z has been on blocks for the two years so I thought before I take it for the test I'll drop the diff and subframe and do the bushes then I know everything was new, the diff and subframe dropped a treat and the removal of the bushes from the frame was quite easy but the diff bush was solid so I had to hack saw it ,it took ages because I had to keep stopping to make sure I didn't go to far anyway I got it out only to find the crack at the opposite side to where I was cutting,personally I think it had been changed before and the crack was a result of that but I don't really know just guessing. I don't think the bushes really needed doing as their wasn't anything on previous test certs, I just wanted everything to be new and not have to strip the Z down again
Derick

 

[t-tony]

Look forwards to seeing your car Derick when we're allowed out again mate. We'll have to meet up for a natter either here at the Shed or out Retford way. Did you find out what the door lock issue was ?

Tony.

 

[Derick Mills]

Wasn't the door lock Tony electric windows, no not sorted yet as soon as the battery goes back on I'm onto it

 

[Derick Mills]

Yes Tony we will meet up again soon I'm going stir crazy not being able to get out

 

[Derick Mills]

Hi does anyone know the torque settings on the diff back plate bolts please

 

[t-tony]

Hey Derek, I replied to your post earlier.

On Bimmerforum Randy Forbes states he tightens them to 45NM.


Randy Forbes

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Originally Posted by MikeMvert
I have been searching for over an hour and have not found the information that I am looking for.

Does anyone have the torque values for the bolts that hold the rear differential cover on? I will be replacing the fluid in my differential soon and seem to have a small leak that appears to be between the case and the cover. I wanted to check the torque on the bolts while I was under there.

Also, do most agree that 52 lb-ft is the correct torque value for the fill and drain plugs? And yes, I do have new crush washers for both. $2.08 for three sets from BMW of Dallas.

Thanks in advance.

I use 45 Nm for the cover and the same for the drain/fill plugs (factory states 75 Nm for the plugs__waaay too tight).

Tony.

 

[Derick Mills]

Thanks Tony

 

[Chris Hunter]

Having just fitted a twin eared diff rear cover to my 3.0, I have a perfectly serviceable rear cover complete with poly bush, to suit a type 188 diff. It may help someone, as I believe they are not so readily available.
Blue skies
Chris

 

[Chris Hunter]

Diff cover

 

[Chris Hunter]

Diff cover