Clutch interchangeability and alignment questions

Here is what I've learned, correct me if I'm wrong:

All 07-11 M8 primaries are replaced with the newer metric primary (p/n 0726-435), which came stock on the 10-11 M8's.

07-08 secondaries still use/replaced by the same ones (p/n 0726-274) and the 10-11 secondaries also still use/replaced by the one they came stock with (p/n 0726-304). The 09's however came stock with a different secondary from the rest (p/n 0726-282) and are replaced by the newer one (0726-304). The 09's also did not use shims behind the secondary to achieve proper offset where the others did.

The 09's are supposed to have an offset of 1.655" whereas the 10-11's had an offset of 1.507".


My questions, regarding my 09 M8:

Can you use the new metric primary with the stock 09 secondary? Or do you have to update to the new secondary, or have the old one machined, to achieve the 1.507" offset of the 10-11 specs?

Do the new metric primaries have a different fixed sheave, thereby changing the required offset?

What is different about the 07-08's that their stock secondaries are still available from cat, and why would they not interchange?


Thanks for any information. This stuff is driving me a bit crazy and I want to get it right.

You're referring to the clutch bolt that goes into the crank I assume. The bolt from my 09 just barely fit past the puller threads on the metric clutch. Had to jiggle it a bit to get it past, but once it's past it works fine. At least on mine.