Re: Why don't they make new trucks with manual transmissions anymore?
Clutch wear is a matter of operation. If you start out hard, slipping the clutch, and slip the clutch with every shift, it won't last long.
I used to run old (1947 - 53) chevy 2 ton trucks. They came with a 6 cylinder and an 11 inch clutch that took both feet to disengage. Usually the clutch was worn out.
I'd replace them with a 9 1/2 inch car clutch, as well as the flywheel and the pressure plate. The clutch was soft, but would hold all the power the engine could put out. I'd start in granny, and match shift through all 8 or 10 gears after that, and I never wore out one of the little clutches.
Engines, however, were another thing. It got to where I could change out a chevy 6 truck engine, working alone, in under 4 hours.
On this issue, a manual transmission can and will invite abuse, especially in this age where most people have no feel for the machinery. A modern electric shift transmission will keep operating parameters within bounds under all conditions, including abuse, and thus relieve the manufacturer in the warranty area.
my 02
John