cookie sti

Hi there my wifes uk 2000 turbo has a TY752VB4AA gearbox thats f**kd the ratios on the box are
1st 3.454 2nd 2.333 3rd 1.750 4th 1.354 5th 0.972 reverse 3.416 T.R is 1.000 and F.D is 4.111
Ive been offered a TY752VB3BA gearbox the ratios on this box are
1st 3.454 2nd 1.947 3rd 1.366 4th 0.972 5th 0.738 reverse 3.416 T.R 1.000 F.D is 4.111
What id like to know is will this box match up to my existing diff or would that need to be changed? looking at the figures both boxes seem to be simular ratios apart from individual gears gearing looks better for acceleration but its like losing 5th gear by the looks of things am i correct in this deduction?

fastmike

iTrader: (4)

the final drive ratios are the same so no need to change the diff

cookie sti

cool that saves quite a bit of work getting the diffs out of both the cars and the extra money to buy a diff. ill have to watch out tho the ratios on the replacement box will make the wifes car a bit quicker off the line she may even beat mine at that rate lol

Splitpin

Something doesn't seem to add up here.

Are you sure this is a UK car?

That's not a UK Turbo gearbox - to the best of my knowledge UK boxes (P1 apart) were all "VN". So either your wife's car is really an import, or the box in it has already been changed at some point in the past?

Also, according to the SPDA here, your info on this box is incorrect. They have the ratios down as: 3.454 2.062 1.448 1.088 0.825 with 1:1 dropgears and 4.1 final drive.

Again according to the SPDA chart, the ratios you quote there are again incorrect. 752VB3BA on there has 3.454/2.333/1.750/1.354/0.972 , so either the SPDA info is wrong or the source you're quoting from is.

Assuming your wife's car has the box you think it does, there would be no need to change the rear diff. However there appears to be so much grey area here about what ratios are coming out and going in, seems like you should be checking a little more closely on what you're taking out and replacing here.

Aside from anything else, a shorter fifth won't do your cruise economy any good.

cookie sti

I wrote it down wrong its a TY752VN6AA the TY752VB4AA is the box in my STI so your right on that but the ratios are still the same as mentioned allegedly except i got them round the wrong way well noticed and pointed out.
the main thing is that the box will fit and diff is ok in it

Splitpin

Provided the final drive ratio and dropgears are the same then you won't have any problems with fitting or reliability. However, the shorter gearing (assuming that's what you're going to end up with) won't do car any favours.

cookie sti

it will lose on top end agreed but it should be quicker up the strip the way i read it the 5th gear on replacement box is the same as 4th gear on original box just as long as the car doesnt top out on the strip which the power its running defo wont then thats fine with us. besides its her w/end toy not a daily driver