Need help with spur/pinion decision

[BrianG]

Using a plastic spur is not necessarily to provide a weak spot, it actually wears better. Plus, it's cheaper to replace if you do mess it up. Regular steel pinions are cheaper as well (and easier to get) than the needed hardened steel pinions.

However, when using steel on steel, make sure you have a perfect mesh your mount DOES NOT FLEX! This flexing is what eats up hardened pinions. And you do NEED to use hardened pinions on a steel spur. Not only are they hardened and wear better, the actual teeth a shaped differently.

Ideally, you'd want some sort of a slipper system to provide the "give" to protect the drivetrain. But really, a buggy/truggy drivetrain is quite robust already.

About the Torsen, I've heard people ONLY using them in the front. Otherwise, it just doesn't handle right. And, some have reported that they are not as tough as regular diffs, plus they are expensive. Personally, I would simply tune your regular diffs properly and let it go at that.