DIY gearbox overhaul?

[dekhelia]

Not sure what gearbox I have, but it's a factory diesel LHD 5-sp ... AAP?... anyway: it whines in pretty much all gears except 1st, and I was wondering how difficult of a job reconditioning it would be. I'm a competent mechanic, having done just about every job on this van and many other cars. Just never rebuilt a gearbox. I realise that some specialist tools would be required, but generally speaking, is this the kind of thing that is beyond the home mechanic? The prices I've seen quoted around and about seem high - and I'm guessing that this is because it's labour-intensive rather than parts-expensive.

Any thoughts?

[CJH]

I can't answer for how difficult a job it is, but I was surprised just how little of my bill was for Aidan's time. I won't go into details, but the parts bill was by far the biggest part of the bill.

[dekhelia]

Hm, that's interesting. Thanks. What did you have replaced, internally?

[Aidan]

I fully support anyone having a go them selves; the information is in the manual which is available online, most of the tools can be fashioned; Brickwerks JK and Heritage between them carry most of the parts, I can help with stuff they don't have
You'll be replacing the pinion bearing, the mainshaft bearing, the input bearing, seals, gaskets, some circlips and depending on what you find other bearings, synchro rings, synchrohub, etc..

[CJH]

Hm, that's interesting. Thanks. What did you have replaced, internally?

Too many things to list, but that's because Aidan returns these boxes to as close to new condition as it's possible to get them. Loads of new parts (seals, gaskets, bearings etc, which mount up surprisingly quickly, as well as big ticket items such as the Weddle 3rd/4th synchroniser) or excellent used parts were fitted, plus some engineering work. As Aidan says, it depends what you find. The current state of your gearbox will determine how much of it can be re-used, how much needs replacing, which bits need sleeving etc.

I personally couldn't contemplate spending all that money on parts (even if I knew where to get excellent used parts) and then making a mess of the rebuild through lack of knowledge/experience for setting up the various tensions, backlashes etc - for me it was one of those jobs that was best left to the experts, even if you do have to plan well in advance. Plus it came back with a guarantee.