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aerobod
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That, too.

James

ScottR400D
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Thanks, James.

ScottR400D
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Anyone know the torque settings for the diff to the diff bracket on the latest iteration of the bracket for the BMW diff? 2 M12 bolts forward and a bolt and nut top rear. 

My manual gives figures for an older bracket.  

Got my diff back from R and R today. Broken Bellevilles, broken carbon plates, bits in the pinion shaft bearing, a few miles away from a catastrophic failure, according to R and R. Complete rebuild needed.

After only 8000 miles. Not impressed. 

ScottR400D
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And does anyone know how much oil to put in? 

CC say 1.2L, RR 0.8L

kiloromeo
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When I built mine with BMW diff (2018/19) the build manual stated 0.8L.

As the general thinking was 'fill it til it runs out' , I actually put the supplied 1L in and it would have taken more (perhaps 1.2L ?). So I checked with Derek at Caterham and he said leave it at 1L.

 

ScottR400D
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Thanks k. I’ve always filled to the hole which has been about 1.2L. 

I’ll go with 0.8 on the basis of what you said. As far as I know the reason for the lower amount is because 1.2 will cause leaks through the side seals, though I never experienced that  

 

 

Geoff Brown
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Some output seals leak some do not. I found that the original output seals on my diff were not set far enough into the casing allowing the rotational variation of the shafts to impinge more on the seal lip. They leaked after 3 years & 10000 miles.

Opinions vary on the oil level because of the differences in build manuals but the current advice of 0.8L is about right to negate any leaks from the output seals.  I must admit the level of my diff has always been 'until it runs out' even after the seal change with no problems. That statement of course is a harbinger of doom!

QUESTION: when did CC implement the fitment of carbon plates?

ScottR400D
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Thanks Geoff. 

Yes, the question of when carbon plates were fitted from still remains. 

My car was supplied as a kit in December 14, and it had carbon plates. 

Talking to Phil at RR he said that the carbon plates worked well for a long time then something changed, maybe an adhesive or something else in the process, when they began to fail after a short time and were replaced by the sintered plates. 

To be honest, it’s a concern to me. If the diff can get into the state mine was in in 8000 miles, and it wasn’t just the plates that had failed, how are they supposed to be fit for purpose? 

ScottR400D
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Well that’s all very disappointing. All back together with completely rebuilt diff and the tapping noise on overrun is still there. 

No noise even with the slightest bit of throttle, just on overrun. You can hear it with car jacked up and spinning wheels, as soon as you stop, tap, tap, tap..........

aerobod
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That's annoying.

Slip-stick under preload of the replacement sintered steel plates, perhaps? Supposedly one advantage of the carbon plates over the sintered steel ones is lower operating noise.

Is it running 75w140 oil? I found that weight quietened down my diff somewhat, although mainly reducing whine.

James