Special tools for early gearbox strip down

[rolesyboy]

Would somebody be able to advise me what tools I need to tackle a 3 synchro Cooper box strip down and rebuild please? I have done a 4 synchro box but have a feeling that the tools are different in some way? Cheers. Mark

[ricardo]

The exact same tools will do.

You'll need:
- the normal socket tool set for the diff nuts + oil pickup pipe, gear levers, etc.
- 1 1/2'' socket for the big nut double roller bearing side
- 28mm/29mm (don't remember the imperial correct size) socket for the first motion shaft side nut
- breaker bar
- hammer + a few thin bars or screwdrivers of different sizes help to reach to some items (reverse shaft, fork plungers, etc)
- something to pull the first motion shaft out is ideal
- clips to pull the plungers to take out the gears

[rolesyboy]

Thanks for the information. Any clues what I need to pull that 1st motion shaft???

[ricardo]

It's the same as in a 4 synchro box. You can use a sliding hammer or some home made stretcher tool. The idea is to pull the first motion shaft evenly out of the casing. The big bearing will come with it. You could do it from inside the case, but it's very easy to hit and damage the case and/or first motion shaft teeth... pushing it out is a better bet. Mentioning this I forgot that you will need a good (big!) circlip pliers for the first motion circlip and a smaller one if you want to replace the idler bearing. If you need to remove the reverse arm, then you'll need another one as the circlip needs to be opened up, as oposed to the others.



In order to remove the outer roller bearing from the first motion shaft, you'll need a puller. However I've managed to do it a few times without one in the following manner:
- Remove small circlip
- Remove rollers from bearing and cage
- Undo the big nut until the thread ends - this will push the inner race of the bearing out
- Fit the nut again until there's space for one of the roller pieces. Fit 3, well distributed and undo the nut until it starts to push the inner race out again
- By the time the thread ends again, you should manage to push the rest by hand or with little effort

[251 ENG]

The first motion shaft nut is 1 1/8" AF

[251 ENG]

Also if you have a very early 3 syncro box the centre mainshaft bearing is smaller on the outside diameter and the " horse shoe " won,t fit