Gearboxes, what to look out for

Hi all!

I've lost reverse gear in my series 3, and all symptoms suggest something massively internally wrong. Shame because it goes in the other direction beautifully.

For a recon transmission I've had prices from £350 to £750, which scares me because you get what you pay for buying parts off suppliers and that's a big price difference.

I think the option within my budget is going to have to be a secondhand box, and coincidentally a 'man down the pub' has one kicking around and he wants £100 quid. Is there anything I can do to ascertain what condition it might be in before I buy it?

Any advice would be much appreciated.

the problem with secondhand boxes is there's very little you can do to get any idea of the condition of the innards, maybe drop the oil and see if anything falls out is really all

the only way to be 99% sure of the condition is to strip it before fitting it unless you know the seller really well

i bought one for a fiver and took a chance (gotta at that price) unfortunately the layshaft bearings collapsed within a month and it got noisy so i took it out really quickly before i damaged anything, it was a really nice gearbox so i've put it to one side with the intention of putting new bearings through it

Having rebuilt several of these units over the years, I would suggest going through the gears with the lever and see how positive the syncromeshs feel.
if they aren't too worn you should still feel a small amount of resistance on the stick and then a positive "click" as you engage each gear.
If it just "falls" into gear or feels sloppy when engaging then I would say the syncros are worn and probably so is everything else.

If you have a reasonable toolkit they are not hard to rebuild with immense satisfaction afterwards.

:5biagree:

All you can do is look at the oil and run through the gears checking engagement and rough turning. Won't tell you if it will jump out of gear though.

If the man down the pub is obliging , you could take the top off and see if the selector forks are very worn. But that won't really guarantee anything.