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Crankshaft thrust washers

Posted: Sun Dec 14, 2014 7:35 pm
by Theo_NL
Assembling my new crankshaft in the new block, I mounted the thrust washers that were delivered with the reconditioned crankshaft. The upper ones first, crankshaft easily turns, no clearance. Assembled both end bearing caps, crankshaft can turn with very little effort. After assembling the center bearing cap (with the lower part of the thrust washers), a lot of effort is needed to turn the crankshaft. According to the Haynes manual a clearance of 0.003" should be kept between thrust washer and crank.

Obviously the lower thrust washers are too thick, although the crank mounted with only the upper thrust washers had no play either.

How can I solve this? Do I need another washer (thinner), or can I carefully grind them (backside) until i have the clearance of 0.003"?

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Re: Crankshaft thrust washers

Posted: Sun Dec 14, 2014 7:41 pm
by panky
Does the crank turn freely with bearing caps in place and no thrust washers?

Re: Crankshaft thrust washers

Posted: Sun Dec 14, 2014 8:45 pm
by bmcecosse
Yes ^^^^ that's a good point.... And is the cap on right way round.... If all ok - then try two of your old thrust washers - put them on the flywheel side of the centre main..so the new thrusts are taking the clutch load. Also double check that there is no dirt/preservative on the back face of the shells. All else good - yes you can remove a small amount from the back face of the thrusts.

Re: Crankshaft thrust washers

Posted: Mon Dec 15, 2014 8:28 am
by Theo_NL
Does the crank turn freely with bearing caps in place and no thrust washers?
Yes, it does.
And is the cap on right way round
Yes, it is

I will check if the old thrust washers are thinner than the new and try mounting both old top and bottom washers at the flywheel side first.

Re: Crankshaft thrust washers

Posted: Mon Dec 15, 2014 9:11 am
by bmcecosse
Aim for 3 to 5 thou end float.

Re: Crankshaft thrust washers

Posted: Mon Dec 15, 2014 12:17 pm
by M25VAN
On your new thrust washers you may find that the marks stamped into the back (part no. etc.) may be standing proud. I have recently replaced some and had to smooth these off. I used a bit of fine emery on a flat surface and slowly worked the back of the washers on this until flat. Don't forget to clean them before putting back.

Re: Crankshaft thrust washers

Posted: Mon Dec 15, 2014 4:57 pm
by Theo_NL
M25VAN, I checked, they are flat at the back, no marks. Thanks anyway.

Checked the dimensions of old an new. Difference 0,05 mm (0.002"). Old ones had only little traces of wear, so mounted them. Problem solved.

Thanks for the help.

Re: Crankshaft thrust washers

Posted: Mon Dec 15, 2014 5:58 pm
by bmcecosse
Good. ALL the old ones - or just one pair ?

Re: Crankshaft thrust washers

Posted: Tue Dec 16, 2014 6:44 pm
by Theo_NL
I used all old ones. With the new ones I had trouble getting the crankshaft in and it was really hard to turn it. Now maybe the clearance still will be small, but it turns freely now.

Re: Crankshaft thrust washers

Posted: Tue Dec 16, 2014 7:07 pm
by bmcecosse
Wise decision...