AWD System Clutch Pack Wear/Longevity?

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Toyota hybrid AWD uses an electric motor in the back for AWD operation. No clutch packs to worry about

Most longitudinal Audi Quattros uses a torsen differential in the center to distribute power front and rear. Newer Audi Quattros have an in-house “Crown differential” that does the same thing.

Transverse Audi’s are Haldex-based. And the newer Quattro with “ultra technology” are electronic clutch pack based also

 

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The weak point on several AWD systems in fords and Volvos, is the 90 degree PTO shaft off the transmission. I think these are probably one or two related families of aisin. The bevel gear and shaft sits in its own fluid and often isn’t serviced.

haldex units also are prone to be overlooked and neglected. They can sometimes be resurrected with hands-on care. As mentioned above, honda’s AWD using dual pump systems is hard on fluid. They work fine if you even half reasonably maintain them, but in a $5k car, I doubt the 2nd or 3rd owner cared.

What’s neglected on a Haldex is not the fluid, but the pump screen on the pump that is rarely cleaned (as it gets caked with stuff). Remove the pump every other fluid R&R and inspect the screen and clean if necessary will keep the pump operating properly. Also the front and rear bevel boxes (VW terminology) needs fluid replacement also. No issues using Amsoil SG 75w90 on my old Tiguan