I'm working on a 86 Trans Am SE and would like to find out what gears it has. I know it is supposed to be on a tag somewhere. Where should I look and what numbers mean which gears? Thanks in Advance.

Brett

 

Pull the cover and check the ratio stamped on the ring gear. The rear probably needs a fluid change anyways and you will be positive what ratio it is and not some speculation.

 

Block front wheels, put tranny in neutral, release e-brake, jack up ONLY one rear wheel off the ground. Make a mark on the wheel and one on the driveshaft (it'll be clear why shortly).

Rotate the wheel EXACTLY 10 revolutions WHILE COUNTING driveshaft revolutions (and fractions of revolutions).

Take driveshaft revolutions observed and multiply by 2. Divide the result by 10 and that's your rear end ratio. It won't come out perfect becuase of observation errors and the slight slop in the drivetrain but it will be plenty good to figure out if you've go 2.73s, 3.08s, 3.23s, whatever.

 

The only way to know for sure is check the ring gear. 2.77, 3.27 and 3.45 were the common factory ratios. Ratios to 4.10 are now available for the 9 bolt.

More information is available at www.9bolt.com

Miles
Diff Solutions