me and my coworker have been trying to figure out what is the gearing and how many splines of the rear of my 1994 Cougar with the 3.8L. any help will help. where not a bunch of sh*h heads, i do every thing on cars but tranys and rears, and he has built a few nice ruststang, but we cant figure it out.
http://www.tccoa.com/articles/gears/gears.html
It's 7.5"... Code Y or 5 I'd guess.
if you feel like changing the oil in the rear, it should say on the ring gear. but thats not a definate. if it doesnt, you can count the teeth on the ring and the teeth on the pinion and figure it out. but thats only if you feel like taking the cover off.
i want to put a different one in and my coworker has a few. but dont know if thay will work. there all for mustangs.
Are you talking ring and pinion, or the whole differential?
Remember, MN12's had IRS...a Mustang rear will not be a "bolt in' thing.
I *think* V6 (not including supercharged) MN12's had a 7.5 gear, all others had an 8.8 diff.