Where can I get shims for crank endplay?

Putting together a 750 and a Mk3, need to set crank endplay. Old Britts used to sell a set of shims that went between the bearing race and the case (not like the Norton shim that went behind the bearing on the shaft).
Who has them?

ace202 said:

Putting together a 750 and a Mk3, need to set crank endplay. Old Britts used to sell a set of shims that went between the bearing race and the case (not like the Norton shim that went behind the bearing on the shaft).
Who has them?

Click to expand...

McMaster Carr

ace202 said:

Putting together a 750 and a Mk3, need to set crank endplay. Old Britts used to sell a set of shims that went between the bearing race and the case (not like the Norton shim that went behind the bearing on the shaft).
Who has them?

Click to expand...

Out of interest how much float do you have !
My 850 came from the factory with 24 thou end float without any issues

everything is going together from parts so I don't know yet but Old Britts article said to shoot for .010 to .015.

Richard Tool said:

McMaster Carr

Click to expand...

I see they have 5 packs of 2.75 od by 2 id in .005 and .016 only
that'll do in a pinch but the Old Britts came with .002, .005, 010, and .015. Easy to get endplay without stacking up too many shims

ace202 said:

Old Britts article said to shoot for .010 to .015.

Click to expand...

That figure was later revised to 0.010" - 0.024" (Norton Service Release No. 68, Oct. '71 at the introduction of the two roller main bearings) although the change didn't make it into the factory manual until the 850 Mk3 copy.

ace202 said:

I see they have 5 packs of 2.75 od by 2 id in .005 and .016 only
that'll do in a pinch but the Old Britts came with .002, .005, 010, and .015. Easy to get endplay without stacking up too many shims

Click to expand...

Scroll down to the 18-8 stainless section, .001 all the way up to .09

Thanks, I was looking further up

For inside drive side case, Mcmaster Carr 2.75"OD x 2.0"ID, many thicknesses available.
.010 linked below part # 97022A409

McMaster Carr is fine for someone in the US, like the OP. They won't supply outside.

I had to go scurrying around to find VW crank thrust washer shims. I found them on eBay and used one to achieve what I wanted. The difficulty is that they are in two thicknesses only, and quite thick.

The thinner one is 0.25mm or just under 0.010" and the other is 0.3mm or just under 0.012". The sizing of a single shim is going to suit many, but if you need just a few (more) thou it could be difficult.

Febi Bilstein part numbers are 01738 (0.25mm) and 01740 (0.3mm).

IMHO those VW shims should be perfectly fine coz it’s just not necessary to get it within a few thou !

Fast Eddie said:

IMHO those VW shims should be perfectly fine coz it’s just not necessary to get it within a few thou !

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Conversely, part of the problem with the original shims is that being only in thin sizes, you can end up with a stack, and I think it is when you have a stack that the are more likely to shift or squeeze out!

Above post edited with a little more data.

IMHO, it's silly to check end-float and then decide to reduce it by shimming the drive side alone (or timing side alone). If you really want to shim, then here's the procedure as I see it:

1) Install the bearings you will use with no shims.
2) Install the crank with rods and torque the cases - no cam needed right now.
3) Install the cylinders with no pistons, don't have to be torqued just well tightened.
3) Push the crank all the way to the drive side and move the rods all the way to the drive side
4) Measure the distance from each of the small ends to the drive side cylinder bore, average the two measurements and record.
5) Push the crank all the way to the timing side and move the rods all the way to the timing
6) Measure the distance from each of the small ends to the timing side cylinder bore, average the two measurements and record.
7) Using those two measurements and checking end float, move the crank to the center and the rods to the center of the journals and repeat until the rods are centered in the bores and centered in the big ends.
8) From centered measure the end float in each direction.
9) Subtract 1/2 of you desired end float from each of those two numbers - now you know the required thickness of the shims on each side.

No, for a street bike I don't bother, and I don't shim. One customer insisted on a blueprinted bottom end for his 73 850 - I did as above. He specified .008 endplay cold and once steps 1) and 2) were done, he had .022". In the end, everything was fully centered with .004" on the drive side and .010" on the timing side to achieve .008" endplay. To me, this proves that just shimming the drive side is bad.

At a minimum, if you insist on shimming, split it in half and shim both sides!

Burnished witness patterns on the inner and outer races from the rollers/balls should reveal whether the crankshaft is laterally centered to determine which side to shim if necessary. My opinion is the outer races will self-center in the cases and stay there as long as they are not wedged in with shims as heat with a big rotating lump will find its sweet spot so they were probably fine the way they were designed and left the factory

Remember, measure before dis-assembly if possible, if that's not possible and old bearing with inner and / or outer race ground to allow easy fitment depending on the shims you are using ie, under the inner race or behind the outer race, will make the job a lot easier and quicker.

Not forgetting you can easily make your own shims using shimstock of the required thickness so only one shim is required.

Simply cut to size required.

I recently did this for a ( car ) overdrive which required the layshaft gear float shimming and the correct parts have been long time NLA

Shim stock, divider to scribe the diameters ID and OD, shears, drill, half round file.

Therapeutic

Does it need shimming, sometime I think most over think things with shimming end float/ play, I have rebuilt/assembled a few Norton motors including my own 2x and I have never checked the end float on the crank, new bearings and slap them together, the 3 motors I put together for mates and 2 motors for friends of friends (paid rebuilds) and all motors are still running without problems (well 2 were sold on but still going) all the rebuilds the owners got machine work and parts that was needed all I did was to pull them down and put back together when everything that was needed to be done.
Seems the factory didn't worry about end play, motor, gearbox, primary all seems to have built in end float/play of sorts, but once everything is button up tight, rotating parts with a bit of end float/play seem to find their sweet spot when running.
Well this is my thinking, and it has worked for me in the 47+ years of owning my Norton and helping mates as well a few paid rebuilds without shimming over the years, but I only done rebuilds/assemble for others in the last 20 years.
I am retired now and only work on my own Norton when needed, no more paid or mates jobs just too time-consuming waiting for owners to get things done or waiting for them to get the parts needed.

Ashley

A good rule of thumb. " They'll run loose but they won't run long tight.

"EVERYTHING needs clearance to move freely"