Gearbox Shims

[Stirlingmoz]

Has anyone got any gearbox shims going spare they’re willing to part with ?

I’m looking for shim/s that will take up a clearance of between 0.577 - 0.627 mm

I can’t make the shims I have add up to the required total.

Thanks in anticipation

 

[Pukmeister]

If it can wait until next week, we have plenty of shim material at work in varying thicknesses. I can acquire a little if you have no offers elsewhere, assuming you can cut/shape it to suit your needs?

 

[Stirlingmoz]

Thanks for the reply @Pukmeister

The gearbox shims are circular ‘washer like’ in appearance.

Really appreciate the offer but I don’t think I could make anything similar out of raw material

 

[Pukmeister]

What dimensions?

I’d need to know Inner diameter/outer diameter.

I have a professional set of FACOM circular punches at work. Failing that I could possibly jump on the lathe and machine up some suitable punch tooling from scrap bar to punch them from shim brass or shim stainless.

If you know the exact size of shim thickness and dimension, I can also machine them up individually on the lathe from bar stock. What material would you need them made from ?? I could make one of exact thickness required or a range of shims to suit.

I’m back to work on 2nd Jan.

 

[Gelandestrasse]

I have quite a few of these, genuine BMW ones - please PM me and we can sort out which ones you need?

 

[Pukmeister]

Gelandstrasse to the rescue !!!

Saves me a job

 

[Stirlingmoz]

Saves you a huge job by the sound of it.

Thank you for the very generous offer and good karma to you.

 

[Stirlingmoz]

I have quite a few of these, genuine BMW ones - please PM me and we can sort out which ones you need?

You have PM

 

[Pukmeister]

It’s not a huge job for me, I could knock out some shims in my lunch break.

My offer stands if the ones gelandestrasse are not the ones you need.

 

[mikeyboy]

What is the size of shim stack you are after achieving?
The shims come in 0.50,0.40,0.30 and 0.20(nominally)
Try not to over think things trying to work to 3 decimal places.
Even if you are super accurate it all goes out of the window once the casing gets warm as it will expand far more than the clusters.
Out of interest ,what running clearance are you trying to achieve?

 

[Stirlingmoz]

Hi Mikey,

Working towards achieving a running clearance of between 0.1mm and 0.05mm.

I am recalling a conversation with Steve Scriminger and he advised to go for the higher end of the clearance range though I can’t remember why now.

I think a stack of 0.6mm would put me in a good place.

 

[mikeyboy]

I personally wouldn’t attempt to go to .05
The distortion as the end cover is torqued up will more than likely put preload on one or more shafts and you’ll end up pulling it apart again to reshim due to a tight shaft.

 

[Stirlingmoz]

Thanks again Mikey.

I have managed to shim the input and intermediate shafts to (theoretically) give me a clearance of 0.08mm.

Shooting for similar on the output shaft.