Boxerworks.com

Is the spring height within specification?

robtg wrote:Too much grease on the splines ended up on the disk.

The Spin Art was dry and I think just came from lube on the throw out assembly. It didn't seem to have made it to the friction surfaces.

bbelk wrote:

robtg wrote:Too much grease on the splines ended up on the disk.

The Spin Art was dry and I think just came from lube on the throw out assembly. It didn't seem to have made it to the friction surfaces.

On the disk, just inside the friction surface there is a lip that has some material buildup, is it dry powder or is it
greasy? Try heating the friction surface with a propane torch and see if moisture boils out---that would be grease.
The friction surface looks contaminated to me but photos can fool you.

How did you check for input shaft play? It only appears as the transmission heats up to operating temperature, usually over 150 F. Set up a fixture for your dial guage, then heat up the whole transmission including the rear too. Now remount the dial fixture and check for the play. Serious grab starts just over the factory spec which is .004 thou inch. We would shim a cold transmission down to about .001- .002" and go with that. At the time that the end play is measured, you want the case to be around the lowest temperature that it is going to see.

Of course room temp with .004" play is going to be much less at freezing. Unless we knew that the bike was going to Alaska, we shimmed it for our moderate weather, numbers above.

Avoid doing the measurements on a hot transmission and then it can be in a bind during cold weather and failing too soon.

George Ryals wrote:Is the spring height within specification?

I will be stopping at Harbor Freight on the way home today and buying some stuff to measure with. I suppose that would have been a good idea before starting this project.

George Ryals wrote:Is the spring height within specification?

I will be stopping at Harbor Freight on the way home today and buying some stuff to measure with. I suppose that would have been a good idea before starting this project.

Duane Ausherman wrote:How did you check for input shaft play?

I grabed holt of the shaft and pulled and pushed. There was no detectable movement on a Texas cold (65 degree) transmission.

Having neither a proper fixture, nor and measureing tool (yet - I may buy one this afternoon) I am not sure I will get a proper measurement. I do know beyond a shadow of a doubt that Colleen won't let me put that thing in her oven.

Having seen what you have seen, do I buy new friction stuff assuming I am:

A) Rich
B) Me
C) Poor

Diaphragm spring 95.00
Pressure plate 80.00
Friction disc 149.00
Pressure ring 200.00

In the shop we measured the spring height by a simple method not available to most. We tset he spring next to a new one. If it was lower by the amount of thickness of the metal, then it was replaced. This was so simple and fast that I have long ago forgotten the numbers.

My site has some clutch stuff on it.

bbelk wrote:Having seen what you have seen, do I buy new friction stuff assuming I am:

A) Rich
B) Me
C) Poor

Diaphragm spring 95.00
Pressure plate 80.00
Friction disc 149.00
Pressure ring 200.00

I got mine from Motobins - very reasonable prices and they were delivered to Oz within the week. I had no idea how light and smooth a BMW clutch could be. I didn't replace the pressure ring - it seemed 'ok' to me. You can test the spring with an inexpensive vernier caliper. Mine was more than a millimetre under spec and the fingers had chewed holes in the pressure plate.