Nuffield Leyland 10 speed gearbox circlip replacement

[jackiejoyjacobson]

Will be trying out my newly backyard-manufactured circlip replacement in the 10 speed Nuffield box, before making the final one that's got to be case hardened. If that circlip design isn't planned obsolescence, I don't know what it is. Or really bad engineering? Impossible to access, remove, replace, throw away the tractor.

If the engineer who designed that box is still out there - hullo, there's no excuse for your design.

Anyway, I had to hunt for a space between the overlapping reverse gear and the main output roller bearing that's ineptly restrained, by a 2 mm wide circlip. This pathetic circlip is supposed to stop the roller bearing inner from sliding along the drive shaft. When the circlip breaks (not if) it blocks reverse gear and two gears get selected simultaneously (wonderful!) I'm hoping i'll be able to sneak in a boltable retaining plate (see photos). I've seen posts where people actually WELDED the roller bearing inner to the shaft. Yes well, OK, but ....
If anyone has the same problem, let me know and I'll post an update.

[jackiejoyjacobson]

Making some progress on in-situ circlip replacement repair.

The gearbox main input bearing outer circlip has ears that project into the space of the main bearing rollers when they drift into the gearbox. They do that thanks to a totally inadequate small circlip that lets go on the fluted main shaft. When that pathetic little circlip breaks, which seems to be a common problem,, the rollers run into the ears of the outer circlip. Not a pretty sound, and you don't go anywhere.

Anyway my original attempt to replicate the circlip restraining the inner of the main bearing was a no-go because I didn't realise how far the large ciclip ears projected into the space.

So I've taken out the large circlip which is 110mm dia and 4mm wide, with a relaitvely cheap Trojan circlip remover. I've shaped two halves of 4mm bisalloy steel to fit into the space left by the circlip. I'm hoping to assemble them with two halves of 3mm steel bolted to the front of the bisalloy, similar to my original inner circlip design (see previous photos).

If it all works out I'll post some photos with dimensions etc. for others so they don't have to throw away a perfectly good machine due to a two dollar circlip.

[Rick Cobley]

Hi, This is not a problem I have come across before, I am trying to work out what's happened, have you a few pictures please?

Regards Rick Cobley