Gearbox-how to work out diff ratio???

85wrx · Post by **85wrx** » Tue Oct 16, 2007 2:53 pm

I am in the process of purchasing an 5 speed AWD gearbox. The guy doesn't know what the diff ratio would be for the rear end. Does anyone know of a way to tell whether it is a 3.9, 4.11 etc?? Any help would be appreciated.
Darryl

Suby Wan Kenobi · Post by **Suby Wan Kenobi** » Tue Oct 16, 2007 3:47 pm

Undo the drain bung and count the crown wheel teeth

AlpineRaven · Post by **AlpineRaven** » Tue Oct 16, 2007 8:45 pm

Do you know what year the box and what car has it came out from?
Plus gearbox number might help?
Cheers
AP

85wrx · Post by **85wrx** » Sat Nov 10, 2007 2:58 pm

Sorry it's taken so long. Just recieved the gearbox today.

The numbers on the sticker are TY752VB3AA. Is from a 94 WRX.

Any ideas as to the ratio I will need for a rear diff.

Thanks regards darryl

PeeJay · Post by **PeeJay** » Sat Nov 10, 2007 3:57 pm

My *guess* would be 3.9

Point · Post by **Point** » Sat Nov 10, 2007 4:50 pm

a quick google reveals.......

JDM Impreza WRX MY93 TY752VB3AA 3.454 2.062 1.448 1.088 0.825 3.416 1.000 4.111

from http://spda-online.ca/modules/tinyconte ... tc_28.html

Point · Post by **Point** » Sat Nov 10, 2007 7:11 pm

if you read the link.....you will find the numbers are the gear ratios 1st thru 5th, reverse, transfer gear, then final drive. So from the numbers quoted....1.000 means there is no ratio change so the rear diff ratio will match the front. ie. 4.111

Point · Post by **Point** » Sat Nov 10, 2007 10:31 pm

no...i searched the gearbox id number

year numbers can be a little misleading sometimes....from the plates on my brumby it could be a 89 or a 90....

D3V1L · Post by **D3V1L** » Sun Nov 11, 2007 12:22 am

my rex is not a 4.111:P....lol...

Point · Post by **Point** » Sun Nov 11, 2007 10:18 am

what is the gearbox code?

SUBYDAZZ · Post by **SUBYDAZZ** » Sun Nov 11, 2007 7:05 pm

And hope to god whomever out that on the 'net got it right