M42 crank thrust washer

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mark_i
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Tue Feb 08, 2011 11:07 am

Anyone know if the M42 crank can be upgraded with 2 additional thrust washers to avoid end float?

TIA
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Royalratch
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Tue Feb 08, 2011 11:16 am

Good queshteeyun - supposed to be a weak spot though cranks aren't usually an issue on these.
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mark_i
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Tue Feb 08, 2011 11:31 am

Thanks Ratch, hoping that Everett has tried this...
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tim_s
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Tue Feb 08, 2011 12:25 pm

The IS only has a thrust bearing surface on the upper main bearing iirc, you can use another thrust bearing from loads of other BMs in there, iirc you need to machine a tab on the main cap for it to fit. I did this on my 2.1 (think I used the m47 bearing), 360 degree oiling on the bearings too. This really isn't worth worrying about too much though imo, I've only seen wear on pretty high mileage engines, and it's not exactly hard to drop the sump off and fit a new set of mains 150k miles down the line if there's some endfloat :).
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Andyboy
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Tue Feb 08, 2011 8:28 pm

You'll need a new crank when you get excessive endfloat. Pressure from depressing the clutch pedal eventually wears through the white metal of the thrust washers and it starts eating into the crank. This was the problem with mine, and it also hammers the oil pump.
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mark_i
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Tue Feb 08, 2011 8:36 pm

Thanks for the replies.
replacing a damaged crank is what i want to avoid happenning, so any ideas on checking the condition of the existing thrust washers?
Andyboy
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Wed Feb 09, 2011 10:53 am

Yes. Measure the crank endfloat. Push the front pulley back as far as poss, and get someone to depress the clutch. Engine off of course.....
If if moves forward with a clunk, you've got a lot of play.
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tim_s
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Wed Feb 09, 2011 12:27 pm

How many miles had your knackered one done Andy out of interest? I pulled a 130k one a few years ago that had quite a bit of wear on the thrust bearings, but most I've pulled have been ok, doesn't seem to be much rhyme or reason behind it...
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bigdogcb
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Sat Feb 12, 2011 5:26 pm

Hi all, I stripped a 110k engine today and the thrust bearing had indeed eaten into my crank, so anyone who would like an m42 crank paper weight, give me a call!
If anyone has a good crank for sale, pm me, thanks guys
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