Gearbox backlash

You can talk about almost anything here

Moderators: John@sos, charlesp, Charles uk, RickUK, Petergalileo

Post Reply
Gannet
Posts: 790
Joined: Mon Feb 27, 2012 9:47 pm
Location: Cirencester

Gearbox backlash

Post by Gannet » Sun Jan 28, 2018 10:44 am

I am rebuilding a couple of the small 10:21 gearboxes of FV/LM/SJM model type and would like some advise as to how much gear backlash to set.
I have been advised in the past to shim the prop shaft so that the gear meshing feels 'nice'. Well, these gears are 60+ years old with some of the expected corrosion and pitting damage, so 'nice' is not what they feel. But apart from that there must have been a factory build and also agent rebuild instruction to set a specific backlash tolerance.
I have provisionally rebuilt them with 0.012 as measured on the end of the prop shaft.
But what is the correct specification? Can anybody advise me?
Thank you.

Jeremy

Post Reply