5 replies to this topic

[tom130691]

im buying a second hand gearbox this evening, with no history on it, what bearings ect are best to change just to make sure ?

obviously a gasket set will be required,

worth getting a central oil pick up and cross pin diff while its out ?

[bmcecosse]

2nd gear for sure and syncro rings for 1st 2nd and 3rd gears. All bearings - including laygear bearings and very probably a new layshaft too.

[Stevie W]

As Roy said above, plus probably worth while stripping the diff and replacing the diff pin for at least a hardened competition item and also fit new thrust washers.
This is a must if you're unsure about the history of the 'box. Wheel-spinning (particularly on one wheel) is a quick way to knacker the diff pin with nasty consequences if not checked!
Cheers, Steve.

Edited by Stevie W, 27 July 2012 - 01:13 PM.

[tiger99]

You should also check that the final drive ratio and speedo drive are correct for your car, and fit new parts as needed. Probably ok to re-use your old speedo drive in the new box, as both gears can be changed in situ if they do fail prematurely, but I would always use new final drive gears.

A new gearbox output bearing, the one behind the final drive gear, is an absolute must. Very bad things such as suddenly and totally locked front wheels, happen if that one fails.

Don't forget the diff output bearings, and the plain bushes in the diff side covers. They may not need replacing, but do need checking. Take the oil seals out (you will be replacing those) and try a pot joint for size. Does it wobble?

Reassembly is the time to fit the anti-leak kit to the gearchange rod, not when it leaves a pool under the car, but I expect you have thought of that one already.

[tom130691]

is it likely to be cheaper to send it to guessworks
i have my old box (diff failure) which chewed the casing, ever had anyproblems getting gears ect from this one, is i abit pikey to swap the gear sets over and use mine knowing my syncros where fine,
but then ive only had the car 4 months and it had a 1275 dropped in so no real history on the engine/box on the car,

[tiger99]

It may well be cheaper, when you add up the cost of all the parts which you would have to buy. I imagine that Guessworks gets a quantity discount on them, while you will be buying single parts. Ask him to quote.