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Posted
Friday, Mar 2nd 8:42pm [Edit] [Quote] [IMS] [View car] |
Post nr. 4
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I am getting a "grinding" noise from the back end. Mostly when power is applied. It seems to ease off when the accelerator is lifted. I changed the rear wheel bearings with no change, the rear brakes are good. I think it may be the centre bearing on the propeller shaft. Any Ideas? |
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Posted
Saturday, Mar 3rd 5:52am [Edit] [Quote] [IMS] [View car] |
Post nr. 1025
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More likely it's one of the bearings in the differential. Prop shaft bearing or center support as we tend to call it here usually ends up in clunking under your handbrake lever during low speed acceleration.
An easy way to diagnose a bad differential is to drain the fluid and look for metal. This is an excellent show of any wear that's been occurring, especially if it's relatively far gone. I've had both pinion and ring gear bearings go bad in various types of differentials- both have sounded relatively similar in my experience. If it's a ring gear/output shaft bearing you should be able to replace it pretty easily. The pinion replacement technically requires a fresh crush sleeve.
A local shop that I know of has actually had good luck reusing the crush sleeve in BMW differentials. He says that he carefully torques it down till it snugs up then goes just a little bit further to ensure it'll hold. Loctiting the pinion nut probably wouldn't be a bad idea either. Supposedly he's done a ton of them with no failures. I'm not certain but if it's not in the budget to have one rebuilt it's worth a shot.
I'd imagine the reused crush sleeve trick would only work if the size and placement of the new bearings are precisely the same as the old ones, down to the thousandth (or less!). Failing that I assume one could always add a small shim to "further crush" the crush sleeve in a BMW diff if you didn't want to wait for a fresh one to arrive from the Motherland.
Of course...there wouldn't be any reason to re-use any of the above if the ring and pinion weren't in absolutely perfect shape!
jamie |
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Posted
Monday, Mar 5th 1:10am [Edit] [Quote] [IMS] [View car] |
Post nr. 121
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This 'clunking' happend to me and I feel like a dick about it.........It was by no means a diff problem......It may not be your problem but I had to get the long wheels studs for my factory optioned BBS-MAHLE gold mesh wheels and they where about 1.2mm too long and where hitting the brakes in the rear hub.......I just ground them down a little bit......I found this out by using my spare (uses shorter wheels studs) on each of my rear wheels and it stopped......easy fix.....if it's your problem....And from the high cost of these machines I hope it's your problem too......Good luck. |
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Posted
Tuesday, Mar 6th 5:52am [Edit] [Quote] [IMS] [View car] |
Post nr. 5
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 Thanks Guys!
I changed the oil in the diff a while back, I only bought this car last summer, best $500 I ever spent. I have no idea how long it was since the last oil change but it was dirty, no metal.
I have BBS-Mahle gold mesh wheels so I will check the wheel bolts for sure. |
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