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Gearbox rebuild vs swap

Posted: Tue Jan 15, 2013 1:10 pm
by Beddo88
Hi all,

So I've come to the decision to keep my Rocco for the time being, I was a little on edge for a while.

On this basis, I'm going to replace the gearbox as the synchros in mine are on the way out, and I'm hoping to do a few sprints/hill climbs in it this year. I can source an identical (barring 100mm output flanges) box with close cut ratios which should be ideal for sprinting, but trying to weigh up fitting the box as is or getting it stripped and rebuilt.

Obviously it'll be difficult to judge what condition the box will be in until stripped, but based on replacing 1st/2nd synchro hub and an 020 rebuild kit which includes diff bearings and most of the bearings/seals on the box, I'll be looking at around £100 on parts.

I know someone locally who rebuilds boxes professionally who will do me a good deal on labour @ around £200, I'm just wondering if it's worth doing it this way or sourcing a 'rebuilt' box online?

Does anyone have any experience with boxes supplied as 'rebuilt'? Tyring to weigh up buying a rebuilt box vs rebuilding one vs fitting a cheapy...

Cheers
Dan

Re: Gearbox rebuild vs swap

Posted: Tue Jan 15, 2013 1:44 pm
by the edmundator
I'd have it done for yourself - that way you know exactly who did the work and what has been done, which means you also get somewhere to take it back to if there are any problems. I'd say this is even more important if you're doing motorsport events in the car, which will put more stress on the components.

Re: Gearbox rebuild vs swap

Posted: Tue Jan 15, 2013 2:20 pm
by james butler
i am running a 1.4 mk4 polo gearbox which only caught my attension as it was an o2o gearbox with a strange semi cable semi rod shift box. the engine had gone bang in it but it had an aluminium sump so was one of the first of the new type 1.4 16v engine but had an old gearbox :dunno:
got the gearbox for 50 quid and its great. 1st 2nd the rocko will spin up the wheels and its only a carbed 1.8. 3rd is a bit of a gap but i suppose in a 1.4 you would have to thrash it through first and second and then cruise up through 3rd and 4th

Re: Gearbox rebuild vs swap

Posted: Tue Jan 15, 2013 2:23 pm
by james butler
i just had a look on google pics on mk4 polo gearbox and they do still use the rocko gearbox.
meant to say aswell my rocko with this gearbox does 3600rpm to do 70mph so may need a longer 5th gear.

Re: Gearbox rebuild vs swap

Posted: Wed Jan 16, 2013 7:28 pm
by Beddo88
I have to agree on getting it rebuilt, I send a lot of customer work to the guy I've got in mind so I trust him! And like you say... if it does go tits up..

Currently mines running at about 80mph at 4000rpm, so not too badly geared. The replacement will be identical ratios.

The FD in mine currently is 3.89, I've been offered one with a 3.68(ish) which while better for motorway cruising, wouldn't be as good for sprinting. I'm planning on getting the engine ancillaries checked over /replaced at the same time.. so hopefullly this will loosen up the horses a little... I'm not expecting miracles, don't worry!

This is all based on me having the spare cash of course... no mean feat in itself in the current climate!