Changing gear ratio from 9.3:1 to 7.75:1...What do I need?

[ChrisW]

This is for a Fury...

I'm wanting to change gear ratio from 9.3:1 to 7.75:1...

As far as the gear & pinion, I know I need to get a 12-tooth pinion and can continue to use the 93-tooth main gear....What other items do I need to finish this conversion? Do I need different clutch side-plates & motor mounts?

Thanks for your help!
-ChrisW

[Dr.Ben]

The Fury series does not support that gear ratio per se. It can be done using the 8.45 mounts and slottting the driver plates and frames. It's a cozy fit, but it does work.

I'm not sure what your goal is, but that gear ratio has proven to be too steep for at least the ST YS 91's for most applications, esp. in hot weather. 7.9 works far better. If you go this route, you can keep the same 11 tooth pinion, buy a 87 tooth maingear from Ricks, and end up doing very little slotting. Use the 8.45 mounts and shim as needed, or get the 8.18 mounts to decrease the amount of shims needed.

Ben Minor