I run on a smallish indoor carpet track (20m x 10m) and I've just bought a 2nd hand TC6. It came with a spool in the front and a diff in the rear and was a pig to drive (back end kept breaking away coming out of corners).

I'm running 17.5 blinky with 40wt oil all round and 2 hole pistons. Silver springs front and green rear.

As I've never been able to get on with a spool, I've bought a gear diff. Is it better to use this at the rear and move the diff to the front or run the gear diff in the front and keep the rear diff as is? What weight oil should I use in the gear diff?

Thanks for any advice