Dolomite 1850 bell housing casting number ...

[Jon Tilson]

Sorry but without seeing exactly what you have its hard to tell....

So is your layshaft reuseable? If not then you can take advantage of the TR7 4 speed layshaft which is available NOS (genuine bits) from Rimmers at a decent price. 1850 layshafts are an arm and a leg...sadly

Then you need the right reverse idler and synchro hub combo to go with that layshaft, which should match exactly the ones normally used
in Spit 1500 and Midget boxes.

Sadly I have run out of suitable reverse gear bits now or you could raid my stock, but any 4 speed TR7 box will have what you need.
Moss also keep a decent stock of bits and Adam Chigwell will tell you what you need if you describe it all to him.

Jonners

[MIG Wielder]

Thanks for that Jon. I did drop in to Moss for some MGB bits, and thats where I got to compare that reverse gear. It looks like gearbox parts are getting a bit scarce.
Anyway to get the mainshaft out you have to remove the speedo drive cog. This was a real pain. And somebody has also been there before me. I was expecting a wire circlip to be retaining the nylon cog, but after a couple of hours of trying to extract the non-existant circlip I went for hack-sawing it off.
This was a big surprise. The white nylon cog had a steel bush under it ! And I had to resort to a chisel to remove that from the mainshaft. It was really tight.
And the next surprise is that there was no ball bearing retainer and no sign of a drilling in the shaft. No sign of a groove for a circlip. The steel bush was smooth bored. My guess is that is was just retained by Loctite ?
Is this usual for an 1850 non-O/D box ?
What do I need as a replacement ?
Thanks,
Tony.

[Jon Tilson]

Yes I have had some grief getting these off canibalising TR7 non o-d boxes for spare bits.

Cant offer a lot of advice other than asking Moss for a new one....

I guess back in the day they came off easilly with the churchill puller...

Jonners