auto diffs in manual ?

Couple of questions
First up whats involed in swaping diffs in a manual to auto


And second is it worth it
I dont want an auto box just the lower ratio diffs

I think they will bolt into your axle fine but I don't know if the spline count is the same to use your shafts. If they differ, just get the shafts from the donor vehicle with the diffs.

If you have a Rocklobster I doubt you'll need to lower your diff ratio's really though, and if you don;t, it will be a better way of getting lower gearing.

Kirkynut

Rocklobster is on its way
So not realy worth it if fitting the lobster then ?

Try it with just the lobster and decide but I doubt you'll see the point.

If you are planning lockers you could get auto diffs if you can pick them up cheap enough and the shaft spline count isn't an issue, you could build the lockers into the auto diffs and then just swap the diffs over.

You then don't lose the use of the car whilst building up the lockers and you'll have lower ratios.

If you're not planning on lockers I wouldn't bother. A Rocklobster completely changes a Zuk!

I'm not sure how much it will affect your speedo, if at all. Someone more knowledgable might come along and clear up that and the spline count question.

Kirkynut

The spline count on all the diffs is the same regardless of ratio, although of course front and rear are different. I think for the small difference it makes its not worth the cost and effort of changing to 'auto' diffs as the difference in ratio is small. If you want to fit lower ratio diffs to a pre 05 car get some from a VVT manual as they are 4.3:1 ie a difference of about 10%. I have fitted these to an early car and although they should be a direct fit, we found that we had to grind a bit of the axle casing away on the front diff as the crown wheel wouldn't fit into the opening. Not a lot but enough to prevent it from sliding in. The rear fitted without problem.
As regards the speedo, best to correct when all mods are made (!) and fit an electronic corrector. This does then allow scope for future alterations. It is particularly necessary for cars with an auto box and changed gearing, bigger tyres etc. From experience the gearbox was confused and changes were at the wrong speed.