I have a t5 tran from a 84 ta and at 55 mph Im at 2100 rpm what rear end gear do I have? I did a search but could not find a answer.thanks.

 

There should be a metal tag that is under one of the rearend cover bolts. that should tell you what you have. Or you could check the RPO codes for your car ( they should be in the center consol or in the trunk on a sticker) and this will tell you what came in the car.

 

already looked for the tags ,there gone. also no sticker.

 

well that sucks! if some one on here has the ability to tell you what rearend gears you have by what you have stated in your first post, then by all means someone give this guy the answer! The only thing i can tell you do do is pull the cover and see what is stamped on the ring gear.

 

i used to have a program to figure the rear end of a mustang with t5 or auto with nothing but rpm at given speed guess you dont have one for these cars.

 

you don't really need the program, math is not that bad if you know your exact wheel diameter and the ratio of the 5th gear, I could do it if you give me those numbers.

But your biggest problem is that you have to rely on your gauges to give you an answer. How accurate do you think that speedo or that tech is? You could do the math and come up with something like 3.31, then what?

Best bet is to pull the cover off. It'll take you 15 minutes, you probably need to change the fluid anyway and it'll be a learning experience.

 

Just pull the diff cover and count the teath. Thats the most acurate way. ring tooth count divided buy pinoin tooth coumt will tell you what gears you have. Its a good exscuse to change the gear lube any way.

 

Check tech section of thease boards . looks to me if it is a stock rear end it should be 3.23's or 3.73's
Tech section

 

Pull the cover, and check the gears, its the only way to really tell.

 

pull the cover and look, the oil needs changed any way since you don't know what you have.

 

thanks