When building the diff you need to set it pretty tight - when I build a diff for mine I tighten it all the way up until the spring compresses, then back it off as little as I can until it looses the locked feeling you get when the spring is bottomed out. Those big tyres are hard on diffs, you need it pretty tight to stop it slipping.
Also the tyres being bigger makes the diff feel looser compared to a buggy when adjusted the same, if you run it too loose you will spin all your power away to the inside wheel exiting corners.
Re the slipper, I've found you can't use the older white slipper pads on the T4 as they are a bit too low-friction. It makes it impossible to adjust the slipper properly, it's either too loose to the point where you start roasting pads/slipper plates or locked up and you kill diffs
A 9t brushless is pretty tame these days, to have something slipping a lot either the slipper or the diff must be
very loose! Is it a smooth/progressive scream when you accelerate that lasts a second or so, or is it a short sharp barking noise?
All of the above applies to the SC10 too
