nutcase wrote:Layshaft/cluster gear shaft are the same thing? This is why I'm thinking we're talking about different parts perhaps?

I'm referring to this shaft (although this is for a late box):

yep, lay shaft and cluster gear shaft are different names for the same thing, they are also both 20mm on 4spd and 5spd, the 5spds is just a bit longer but you can cut them down to use for a 4 spd.

So perhaps the 79 case doesn't need machining? Although from what I can see the layshaft is the same part for -78 (i.e. drop gears) and 78- (chains)?

nutcase wrote:So perhaps the 79 case doesn't need machining? Although from what I can see the layshaft is the same part for -78 (i.e. drop gears) and 78- (chains)?

I'm still not sure exactly which part the original poster was saying needed to be machined...
I think we need a picture.

I think you have to machine the main case to use the new gearset. 1 or 2 mm. Inch?
Messure from the top of the case to the edge of the lay shaft hole.

Luke wrote:

nutcase wrote:So perhaps the 79 case doesn't need machining? Although from what I can see the layshaft is the same part for -78 (i.e. drop gears) and 78- (chains)?

I'm still not sure exactly which part the original poster was saying needed to be machined...
I think we need a picture.

That was me via Rob Walden. I'll take a pic this weekend and some measurements.

http://www.uksaabs.co.uk/UKS/viewtopic. ... 9&start=30

Is this what we're talking about?

Ah that may make sense. I've probably read that thread a million years ago to...