Has anyone here rebuilt a TuffTorq transaxle?

[nomail]

My Countax C600H mower is losing drive when warm and struggling with slopes. Replacing the belts has made no difference so it seems that it's the transaxle - a TuffTorq K46 (judged from the parts diagram). Mr Google seems to think that it's a common problem, there's a good overhaul write-up here:

but the overhaul kit is quite pricey and needs to come from the US. Has anyone here had any experience of overhauling these transaxles?

[newshound]

I had a (very old and battered) Laser ride-on mower, the one axle problem I had was (I think) corrosion on the gear change spindle. In the end I dropped the whole unit out and got it to free up with much wiggling and penetrating oil. However as far as I could tell there was not much drag in the gears. After layup for the winter, the gear change seized up again and I replaced it with a towable motorised topper. So no help, really, except to warn you to clean up the gear change shaft at the same time.