Gearbox refurb?

Where local (Sheffield) can i go for a gearbox refurb, my diff is no good,
Thanks.

think you will find somewhere if you google it, mine just gone aswell so been looking into it but looks cheaper to get a new box (i got quoted £50 just to take it to bits then parts and labour for whatever needed doing)
cheers
jamie

googled a few up but they dont give much info mind, probs be easier to buy a new box but this is my second box now so aha ill have a nosey round again anyway at weekend when i get a min