Gearboxing

[350matt]

Hello chaps Does anyone know how many variations of back axle exist for a wedge, as I''ve recently fitted a new rover gearbox as the original was well past it, unfortunatly the new top-gear ratio isn''t as high as the old one, so I''m now looking to either replace the diff ratio with a higher one or squeeze in a larger diameter wheel tyre combo. Whats the largest overall diameter that will fit? Or what sort of crownwheel and pinion combo''s are there? Ta Matt

[Greenv8s]

Sounds like you got the Sherpa box instead of the Vitesse one, D'oh! Sure you don't want to swap the box instead? Peter Humphries (and a green V8S)

quote:Hello chaps Does anyone know how many variations of back axle exist for a wedge, as I''ve recently fitted a new rover gearbox as the original was well past it, unfortunatly the new top-gear ratio isn''t as high as the old one, so I''m now looking to either replace the diff ratio with a higher one or squeeze in a larger diameter wheel tyre combo. Whats the largest overall diameter that will fit? Or what sort of crownwheel and pinion combo''s are there? Ta Matt

[350matt]

I've had the bl##dy box in and out 4 times now (addmittedly getting good at it) first time to rebuild it myself, 2nd time to get someone who knows what they're doing to rebuild it. 3rd time to return it to the so-callled experts after they'd fitted the incorrect snychro's, 4th time to replace now very k'ned box, with this brand new box found at a SD1 swopmeet(receipts to prove from Rimmer's and everything). If it is a Sherpa box that may prove to be a bonus as weren't they supposed to have shot-peened gears? In any case I thought the car was a little undergeared before I fitted this new box, so I'd still be intrested to hear if anyone has geared up a wedge and by what means. Matt

[jmorgan]

Is the box an engine out job or can it be done in situ? Mine's guess work as to which gear it is in. Have to be careful at the lights so I don't bend the car behind.

[350matt]

You can do it with the engine is in situ but you still need a crane to support it as you have to slide the engine foward about 6" then you can drop the box out from underneath. Matt

[shpub]

1. It is either engine out or support engine and move it forward. As clutches have been declared a consumable on the 520 (3rd fitted since April), Tower View modded its chassis so the gearbox can be dropped from underneath. Needed addition chassis strengthening and a special cradle to get the propshaft alignment correct but it does make clutch/gearbox work a lot easier. 2. Gearing can be changed by replacing the diff with a SEAC spec higher ratio. Effectively turns first into second and you need a lot of torque to get the car off the line. Hard to find as it was an option. There is an excel spreadsheet on my web site (www.tvrbooks.co.uk) that you can use to play what if games: plug in diff/box ratios, wheel and tyre sizes and it will work out revs/mile etc. Steve www.tvrbooks.co.uk