MTFCA Forum

Are there any differences in the coupler to connect a TT rear end to the driveshaft? We had a coupler in a working snowmobile with a ruxstell and Watford come apart .we had a spare stock rear end so we took the coupler off of it but it won't fit? Splines seem off.splines on rear end drive gear could have a twist I guess but look ok

There are 3 different splines for the worm gear / coupling / drive shaft and they don’t interchange; Early TT, Late TT, & Model A

Thanks for the info Adam

Here are specifics on the TT variations:

1920:


Then, by 1924, they realize the mis-match causes problems and tell you not to do it!

1924:


The couplers began to be “marked” late 1924…

Later in 1924:

2 different depths of splines. I think you can use a deep coupler with a shallow splines shaft, but definitely not the other way around.

tom_strickling wrote: ↑

Sun Mar 22, 2026 12:21 pm

2 different depths of splines. I think you can use a deep coupler with a shallow splines shaft, but definitely not the other way around.

I think maybe that's the other way around. The deep coupler has a minor diameter smaller than the minor diameter of the shallow spline shaft.