View Full Version : Difference between 02 formula and 04 GTO T56?

05-02-2012, 10:50 PM
I have a 02 formula with the T56 and a 04 GTO T56. The only difference between the 2 trans that I can see is the tail housing.
Could I swap out the tail housings from the formula trans to the GTO trans and use it in the formula?

05-03-2012, 07:53 AM
the bellhousings are different however you can use the gto bellhousing from a gto as long as you use a gto starter. the tail housing can stay you just need an fbdoy shifter and shifter cup and your good to go thats it.

05-03-2012, 08:18 AM
The transmissions are externally very similar. Like redbird555 said, the shifter and shifter block. The starter area of the bell housing is smaller on the GTO. But if you have both the f-body and GTO T56 bell housing they will interchange.

Internally is where most of the differences are. The f-body T56 ratios are 2.66/1.77/1.30/1.00/.74/.50. The GTO T56 has a 2.97/2.07/1.43/1.0/.84/.63. The GTO also has triple cone synchros where as the f-body T56 has single cone synchros.

05-03-2012, 10:25 AM
Thanks. The only reasone I'm considering the swap is I had a vibration with the clutch pushed in and reving the motor. I pulled the trans out of my formula and tore it down and I could tell it was a fresh rebuild,so I didn't replace all bearings. The bearing on end of the counter shaft(5&6 gear)were it sits in the tailhousing was bad. I replaced it and the race,put it back end and two days later same thing. I have no idea what would be causing the problem.

05-03-2012, 10:31 AM
With the clutch disengauged nothing in the transmission is moving. I would start looking at your clutch/flywheel combo.