Transmission Shim measurement

[DonW]

Hello All, I have 3 trannys apart, all the bearing checked or replaced, ready to go back together. Soooo... I have to shim the damn things. I have a tool to measure the depth, but my ability to accurately use it didn't work so well last time.

I also have some "mold-a-gauge" from Cycle works, and will try that.

Here's the question- I saw here- - a way to use soft solder as a measurement gauge for shims. Anybody done this? Suggestions? Seems like it would work great, and take the guesswork out.

Don

[ME 109]

Gidday Don, several people have done it over on ADVrider, 'olds cool'-'airheads'

With the correct diametre solder, about 2mm, and soft enough like resin core, there is a good chance to get a close enough measurement.
Aim for min/max clearance .1mm or 4/1000

[Roy Gavin]

Only problem with the system is that the measurement should be taken to the inner race when it is uncompressed.

Someone compared the difference between readings, one the correct way on the uncompressed inner and one with the compressed solder on the outer, and it varied between between 7 and 10 thou on the 3 shafts, so this should be taken into account.
You wont notice much difference immediately if you get it too tight - I pulled a box after 30 km after the PO had it professionally rebuilt which had 25 thou preload on the output shaft and it took that long to destroy the shaft and cases, so with 7/10 thou too much you might get 50/60,000 km out of it, depending on the lube - I was using M1synth.

[ME 109]

If there is no end float on one or all of the shafts, it can be felt at the input shaft by hand.
There is a distinct difference in ease of turning the input shaft when there is no end float.
When I rebuilt my tranny recently using a cycle works plate, there was a difference in measurement from the inner to outer bearing. Surprising, but it was there. Considering the shims are placed under the outside of the bearing, I don't understand why the inner measurement is considered, unless it is suggested that the outer is 'dropped' and the true position of the bearing is indeed the inner.

The input shaft is really easy to turn when the box is assembled and there is end float. If that is not the case when everything is buttoned back up, do not be satisfied with it. Fix it, or you will be fixing it soon enough.
To give further insight, I could tighten most of the rear cover retaining bolts while maintaining a free turning input shaft. When I snugged the last three bolts near the output shaft, I lost the free turning. It is that easy to loose it.

[Roy Gavin]

That was the only way old Brit boxes were checked - you just added shims till you could feel some drag, the went back to the previous setting.

No reason it wouldnt work on an Airhead, but an old box with with the bearing pockets opened out a little would make it easier.

[ME 109]

I wouldn't want to rely on 'another' rear cover to ascertain shim measurements.
Considering end float is ideal @ .05-.1mm or 2-4/1000" or the thickness of 1-2 cigarette papers, I doubt machining tolerances were that consistent.

It is critical to ensure the shafts (front bearings) are fully seated in the front bearing pockets.
80-100 celsius at the bearing pocket area, and tapped in with a copper/plastic mallet.
Not preaching to you Roy, rather general information.

[Garnet]

I still follow these threads whilst working up the nerve to find out what exactly is whining in my box.

[Major Softie]

I still follow these threads whilst working up the nerve to find out what exactly is whining in my box.

Do you know where your wife is????

[ME 109]

Do you know where your wife is????

Does Garnet have a box?!

[Garnet]

Does Garnet have a box?!

Several: One that clunks, one that clunks and whines, one that snicks, and one in the living room that I spend way too much time looking at.