Shimming crank

Gator · 2026-09-30T03:18:57-0600

I am shimming the crank shaft on my G15cs and to save trashing bearings ive decided a different approach. Ive taken internal case dimensions (bearing seat to bearing seat) subtracted the crank (Cheek to cheek) to come up with bearing allowance. After the bearings have been subtracted i have allowance for shimming .007 on the timing side and .0192 on drive side. I believe the timing side should have the lease amount of play considering this was the intention of the original ball bearing on the timing side. These engines need an end play of between .005 and .010 . For some food for thought what is anyones logical thoughts on this and where would you place the shims and how many and why ? Shims are .003 thick

kommando · 2026-09-30T03:47:30-0600

Discussion on the Commando.

Thread 'Shim crankshaft, which side?'

Sep 12, 2026

Checked end float today on fresh superblends. Crankshaft is not oig to this engine. Both 750. Engine is 1971. Float measures .026-.027 repeatedly. I ordered 5 shims from Baxter, intending to need 4
If this works out, which side to shim? Or 4 ea side?

baz · 2026-09-30T05:07:15-0600

Gator said:
I am shimming the crank shaft on my G15cs and to save trashing bearings ive decided a different approach. Ive taken internal case dimensions (bearing seat to bearing seat) subtracted the crank (Cheek to cheek) to come up with bearing allowance. After the bearings have been subtracted i have allowance for shimming .007 on the timing side and .0192 on drive side. I believe the timing side should have the lease amount of play considering this was the intention of the original ball bearing on the timing side. These engines need an end play of between .005 and .010 . For some food for thought what is anyones logical thoughts on this and where would you place the shims and how many and why ? Shims are .003 thick

I wouldn't worry about shimming the crank tbh
But if you do then make sure you put them between the outer bearing and the crank case
Not between the bearing and crank as these can give trouble

Gator · 2026-09-30T06:00:35-0600

baz said:
I wouldn't worry about shimming the crank tbh
But if you do then make sure you put them between the outer bearing and the crank case
Not between the bearing and crank as these can give trouble

So you recon a .006 shim between the bearing inner and the case on the timing side ?

kommando · 2026-09-30T06:22:59-0600

Its shim between bearing outer and the case but only if you consider it required, I would not bother. The ISO shims may fit the bearing outer and case but may need some trimming but my memory could be off on that one.

baz · 2026-09-30T08:06:04-0600

Gator said:
So you recon a .006 shim between the bearing inner and the case on the timing side ?

Technically you should put an equal amount either side
But why bother?

Shimming crank

Gator

kommando

Thread 'Shim crankshaft, which side?'

baz

Gator

kommando

baz

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