transmission determination - how to determine final drive ratio?

[gwahir]

Sometimes, with an older reworked Geo, there may be some confusion as to what transmission is actually in the car. I want a simple test to determine what transmission is in a Geo, and I need help. If we pull the plugs, place in 5th gear, and push the geo one full rotation of the wheels, how much crankshaft rotation would there be for a regular geo transmission, an xfi transmission and a suzuki swift transmission?

[cfg83]

gwahir -

Don't know how to help, but I do know that on Saturn S-Series, there is a serial number on the tranny that is matched to a serial number on the engine block. If the tranny or engine is swapped, the serial numbers will no longer match.

Are there any serial numbers on the Geo tranny?

CarloSW2

[MetroMPG]

I'll see what I can dig up tomorrow and post back.

[MetroMPG]

The gear ratios are all the same for these cars - only the final drive is different.

5th is 0.757

Final drives:

4.39 - 1.0L garden variety (1995 and up), 13 inch wheels
4.105 - 1.0L garden variety (1989-1994), 12 inch wheels
3.79 - 1.0L XFi (1989-1994), w/12 inch wheels
3.523 - 1.3L SOHC (1989-1994), w/13 inch wheels

So multiply 0.757 by each of those final drive numbers, and that's how many times the crankshaft will rotate for one full revolution of the wheel.

EG. 4.39 * 0.757 = 3.323 crank revolutions per wheel rev.

[gwahir]

Thanks. To me, very useful information.

[MetroMPG]

Good luck - let us know what you find out.