Triumph Pre-Unit Gearbox Assembly/ Rebuild

This is a 1937 Triumph T70 Gearbox which was rebuilt due to a failing bronze bush on the main shaft. I've seen online a few people expressing difficulty in regards to the cam plate position which allows you to selects all gears correctly. Failure to line up your datum's means multiple strip downs (Which no one wants!)
I hope this video will help you in every way !
Regards YoungOldJoe
P.s - Upon rebuilding I soaked all the gears and bushes in good quality SAE 70-90 oil to ensure smooth lubed running from the get go!

[@alistairbernard9574]

A Great Video. Excellent Build of the Pre Unit Gearbox with easy to follow and correct methodology. The Guy who built my 58 5T messed it up totally that it had to come out again and again. 🤦‍♂️ Finally a Mechanic friend of mine put it right. 🙃😁

[@BPantherPink]

Beautifully explained and illustrated...Thank You

[@sooperzero4087]

Thanks for taking the time to share your knowledge. Cheers

[@brustar5152]

Then there is the 1958 pre-unit introduced Slick Shift transmission which was an available option until 1962 I believe. I had a 58 TR6C with that and the lucas compi mag and rode that thing trouble free for years until trading it in for a new 1968 TR6R. Love your vids.

[@leemelling443]

You made that look easy!!

[@slaapstad]

Enjoyed this - thanks! Noted that marking neutral while stripping makes life easier in the long run!

[@alangillard7026]

Wot if you don't mark them or you have to reassembly gearbox from a box of bits with no marks on them

[@slaapstad]

@@alangillard7026 I would imagine that it would be best to follow the instructions in the Triumph workshop manual if you're assembling from parts.

[@peticiclo]

Thanks for the video. my gearbox is exactly the same, but when I disassembled I didn't put a mark on the neutral of the camplate, so now the gears usually come loose and it stays in neutral. I have to disarm again. Oh my God!

[@Oscar-776]

Nice one Mate! Very informative! Where did you get that neat vice and mallet? 😅

[@Motocicloman]

Great vid but i was really looking how to pre tension the kick start spring whilst putting the outer cover back on.

[@youngoldjoe3026]

Hi, have you sorted your kickstart spring assembly yet? Sorry I didn't video it. From memory I wound the spring back with the kickstart dowel on the centre case then pushed the outer case flush against it with the kickstart held downwards (compressing the spring) a BSA will be the same so It may be worth looking up a gearbox assembly video for that 🙂 ATB YoungOldJoe

[@AskingForAFriend]

Where can I fine measuring tolerances of gears and shafts? Can’t find anything

[@wreckrat1]

Excellent video but could you explain the difference in gear selection with the gearshifter in the position you have it...ie you have it in the 1 up 3 down direction, typically the shifter is the other way resulting in 1 down 3 up...if that makes sense...

[@youngoldjoe3026]

Hi @wreckrat1, I see what you mean, I would imagine if the gear shifter was the other way (pointing forward) when you clunk down to go in to first you would select second, meaning when you clunck up you would find neutral ect ect it's hard to imagine but I'm fairly sure it would work out that way 😉 you could always try it to be 100% and see what you prefer

[@jumpfortyfour9965]

could you please do a video of unit tr6 triumph please

[@youngoldjoe3026]

Hi Jumpfortyfour, Im afraid I don't own a TR6 engine/gearbox so I cant, However if I come across one ill be sure to do a video!

[@jumpfortyfour9965]

thank you very much for your reply