Timing Side Main Bearing Washer/Shield

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thunderbolt

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Can anyone tell me how the timing side main bearing washer (Part # 067526) should be mounted on the crankshaft? Should it be a tight fit in the timing side crankcase cavity or should it be a tight fit on the crankshaft and spin with the crank and timing pinion, etc. If so what is the solution if this washer is a tight fit in the crankcase cavity (hole)?

Thanks
Don
 
Thanks Les,

Bugger - I was afraid of that. The disc/washer/seal that came off originally was a firm fit in the crankcase and the new one I have purchased is .018" bigger in OD. Is it normal to have them this tight in the crankcase? Any issue with the steel disc wearing away the alloy of the crankcase as it spins or should there be a small clearance between the two?

What is the best way to fix it? Try and take some metal off the OD of the disc or is it permissible to remove some aluminium from the ID of the large hole in the crankcase?

Opinions welcome.
 
thunderbolt said:
What is the best way to fix it? Try and take some metal off the OD of the disc or is it permissible to remove some aluminium from the ID of the large hole in the crankcase?
Click to expand...


You could do either. I would say the most logical option is to reduce the diameter of the washer if the bottom end has already been assembled and maybe reuse the slightly smaller old washer if it's undamaged.
 
The crankcase halves are still apart. Waiting on new conrods as my little ends had too much play in them. I might remove the superblend outer and with a large half round bastard take a little from around the ID of the case till the new disc fits neatly.

The old disc got damaged when I was removing it as I couldn't get the half time pinion off the crank before I split the cases and had to prise it off with tire levers once I had it in the vice.

Thanks Les
 
thunderbolt said:
The crankcase halves are still apart.
Click to expand...

That's ok then, Mick Hemmings does mention in his engine restoration video about checking that the crankcase doesn't "grip" the washer before assembling the cases.
 
L.A.B. said:
thunderbolt said:
The crankcase halves are still apart.
Click to expand...

That's ok then, Mick Hemmings does mention in his engine restoration video about checking that the crankcase doesn't "grip" the washer before assembling the cases.
Click to expand...

Does he really!!! I have the video but have never noticed him saying that. I had better re-watch it.

Thanks Les
 
thunderbolt said:
Does he really!!! I have the video but have never noticed him saying that. I had better re-watch it.
Click to expand...

Disc 1, 42:33.
 
dynodave said:
I have 6 disc's right behind me on the table
They range 1.8685" to 1.873"
Click to expand...

That's only .0045" difference, which is not that much. The new one I purchased was .018" larger - that's a lot in my mind. My issue is how to reduce the washer/shield to the correct size and take off an even amount all the way round - I don't have the luxury of a lathe or other fancy equipment. Maybe I can use my angle grinder mounted in the lathe and slowly rotate the washer around taking off small amounts and taking lots of measurements with the vernier to get somewhere close.
 
Buy the right disc. If yours is too big, send it back. It should fit snug on the crank and go tight when crank nut is tightened. It should not rub on the crank case but it should be fairly close. It is a baffle to stop too much oil getting on the primary chain from the crank case.
Dereck
 
kerinorton said:
Buy the right disc. If yours is too big, send it back. It should fit snug on the crank and go tight when crank nut is tightened. It should not rub on the crank case but it should be fairly close. It is a baffle to stop too much oil getting on the primary chain from the crank case.
Dereck
Click to expand...

Do you mean primary chain driving the clutch??
 
Its job is to stop too much oil from the timing chest flooding the main bearing, which could cause the bearing to skid.

Martyn.
 
Sorry. I did mean timing chain, and it knew it was supposed to stop too much oil passing, but forgot which way. Too much oil can cause havoc with roller bearings.
Dereck
 
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