Differential Ratio

How I can know differential ratio of 7M-GTE engine.Because my cars was change engine from cougar to 7M and diff. can not match with transmittion.

Thank for your answer.
Somkeat.

[suprra_girl]

hey
to check the ratio of the diff the way i've always checked them is......

place a chalk mark or something easy to see on the driveshaft end of the diff and a chalk mark on the top center of one of the side axles on the diff

see how many times it takes to turn the driveshaft end till the chalkmark on the axle bit comes to the top again...
generally 7mgte diffs 86-88 are 3.9 lsd and 89-92 are 3.7 i believe...

so generally you would have to turn the driveshaft end of the diff 3 times and almost one more rotation to get the ratio

let me know how you get on or if my instructions totally don't make sense lol

also.. what do you mean you can't match it with the transmission?

thanks

[MA70-1JZ]

Have a look on the build plate of the car..various differential codes mean different ratios..Once you know the code on the build plate look it up on the net. I am sure that you will be able to find it out from here

[suprra_girl]

lol
the engine and diff is a replacement for a cougar lol
if it has the transaxle code for the 7m in it i'll be highly surprised :P

[mrnickleye]

Speaking of Diff ratios....has anyone swapped a diff from an N/A into a turbo ?? I believe I read on some website that the '89 N/A (mine) has 4.33/1...and the turbo had 3.7/1. I wonder if it would give the turbo version a better 'holeshot' on the dragstrip ?? or just be too low??

[suprra_girl]

well it has been done.... and out of the hole it is really good... but you may run out of legs
it should go alrite