I'm curious - how long are the clutches for the common 5-speed manual trans for the 4.2 lasting? Anyone replaced one? What can the rest of us low-power guys expect?

 

Depends on the driver, and many other variables.

I've seen clutches last 50k to 300k on these trucks.

If you drive it like a granny, it might last well beyond 300k.

Also, if you regear the rear end, to say 4.10's... you don't need to rev the truck to get it rolling. So that extends clutch life a lot.

 

My 1990 with a straight six still has its original clutch. My new '08 is effortless in comparison. I wonder if its lighter duty, or if they've just refined the mechanism to make it easier to operate.

 

Don't know about the mechanics, but that's impressive! You're looking at 20 years soon!

 

The slave cylinder will start leaking before the clutch is worn out.

I've heard that as long as the slave doesn't leak, you can expect about 150k out of the OEM clutch.

 

my slave leaked as soon as i rolled over to 168,000 miles. not 1/10th mile past, truck breaks down. so when they tore it down, the said the clutch was a good 4/5 into its life span, so i told them to go ahead and replace it. $1300. when i got her back, she was REALLY touchy on the clutch (i chirped the tires backing out of the lot and not even touching the gas. spun them when going into first, again not even touching the gas. it scared me for a second!) but a few days later it wore in.

M5OD 3.55 Non-LS