Chevy 6 speed

[esommer2500]

My boss has an 02 Duramax 3500 ext. cab with a six speed. He was really disappointed with the power after having 3 Dodge/Cummins trucks. This truck was a political move, as we pour a lot of concrete for the local Chevy dealer owner. Boss also REALLY likes the ride and interior of the Chevy. I picked up a SuperChips Micromax Tuner while at Schied's in August, and after sending it back to be reprogrammed once (different story) got it installed a couple of weeks ago on the intermediate "Tow-Safe" setting, about 40-50 hp added.



This woke the truck UP! No other mods, no air/exhaust, guages, etc. Truck has 58,000 miles. About a week later, the clutch appeared to be slipping, especially with trailer (~6K-10K) in tow. We're good friends with the Service Manager, and he put a new clutch in under warranty while we were in Michigan last week on business. Boss called me today and said the truck still seems to be slipping. I haven't talked to the Service Manager yet to find out the specifics of the old clutch, etc.



Anyone know any specifics about the Chevy clutches? I wouldn't think that adding a mild increase would turn the clutch so easily. Coincidence? Bigger problems in the transmission? Any thoughts, please let me know. TIA.



Eric

 

[RustyJC]

I'd give Peter at South Bend Clutch a call (800-988-4345). If anyone knows about Duramax clutches, I'd put my money on him!



Rusty

 

[J DeMaio]

I read where the stock clutch wouldn't take a whole lot. The Duraxax is about double the horsepower, ~120 ft, lbs of torque more than the older Dodge trucks. Add the power and it's decent power, the clutch just wasn't designed for that. I'll tell you what, the 6 speeds are hard to find uless you order one (I may this spring). Everything I've heard about them have been good. It's a ZF, Ford has used them behind the stroke for a while, not sure if this is what dodge uses behind the cummins or not. I'd call Peter@SouthBend or TST. Just start surfing the web, a lot of the links on here are not just for the cummins, they have parts for the big three.



John

 

[Gonzo 1066]

SB

Yes I would go South Bend for a clutch again in a heartbeat. The one in my 02 Dodge works great.

I would be quite wary of the ZF transmission. It is a aluminum case and under higher torque loads they have been very short lived. A friend of mine has 2 of them in PS trucks and has yet to get over 40,000 miles out of one. Seems the input bearing is a weak link. When the input bearing goes out so does the transmission case. $$$$$$$$$$. I personally find the shifting pattern confusing and narrow gated. I guess you have to pay extra for a lighter transmission with a shorter life. IMHO

 

[RustyJC]

Originally posted by J DeMaio

I'm not sure if this is what dodge uses behind the cummins or not.

Nope, Dodge uses transmissions manufactured by New Venture (I would have thought GM would as well since they were a party to this GM/Chrysler joint venture. ) Anyway, Dodge uses the NV4500 (5-speed) or NV5600 (6-speed) gearboxes behind the Cummins.



Rusty