VCU stands for Viscous Coupling Unit. It is the componant in the center differential (which is located in the transaxle) that resist uneven torque distribution (like when the front wheels are trying to spin faster than the rear wheels) between the front and rear axles. Jeff's site,
www.stealth316.com has excellent pictures of the inside of these transaxles and a good description of their operation although a bit heavy on math stuff for some members. Still check it out for more details and if you have any questions about it feel free to ask me any time.
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When asked what the best thing to come out of Italy is, most Italians will tell you Ferrari.... But if you ask me it was Super Mario Brothers. 
250 RWHP
If you want the exploded views of both 5 and 6 speeds or pics e-mail me at
SavagTiger@AOL.com.
94 VR-4 Panama Green Tan Interior
RPS II, gutted cats, flipped BPV, 3SX control arms, 3SX shift bushings, Red Line, Auto-Meter. Rebuilt TC, transaxle, steering rack, heads, and turbos. 360cc's blue printened with in 1%. New short block. RWD convertion and welded rear end.