I have a 04 Dually 3500 Duramax w/6 speed (49k miles) and tow a 38' goose-neck enclosed car hauler. My clutch pedal gets hard while I'm driving. When I feel the clutch starting to slip, I'll push the pedal in and experience a "hard" pedal". When I release the pedal it stays close to the floor and I have to pull the pedal up. Sometimes this happens on the highway, on a level surface under no load. At times pulling a hill and I'll feel the clutch start to slip, I'll push the clutch pedal in and its "hard". I read a lot of old posts to correct this problem and was wondering if anyone came up with anything recently to solve this issue.

My 02 did the exact same thing. I had a new south bend dual disc clutch put in and the problem stopped (doesn't slip at all). I'm assuming the heat from the slipping clutch boiled the hydraulic fluid, creating back pressure in the line.

Clutch is shot! My truck did the exact same thing before I put in my SB dual disk clutch. Then on a trip down to L.A. California, it would only get hard after a couple (3-4) hours of solid driving without any clutching but no slipping at all even with a PPE programmer on level 10. Ive been told to replace the clutch oil with DOT 5 oil and did so. I'm making another trip to L.A. in 3 weeks and I'll be able to tell you guys if the pedal still will get hard or not with the new oil..

Give Peter @ Southbend Clutch a call. He will advise the best solution for your application and needs.

Great guy to deal with!

You definately need a new clutch/flywheel as the others have said.

I was about to make my own thread on this but I figure I'd chime in here instead. This happened to me for the first time (clutch staying at the floor) this morning in to work. I was going about 45mph in 6th behind a semi and I went around him barely giving it any throttle. When I came to a stop about 500 yards ahead, my pedal moved about an inch and stayed on the ground until I pulled it up.

I've experienced the stiff pedal on highway driving/long trips before any programmer was installed. I spoke to a gentlemen at midwest transmissions and he thinks it's due to the clutch fluid getting too hot because these things have an internal slave assembly. So, I'm thinking, even if you upgrade to a SB clutch, the pedal thing will still happen.

My question is, when the pedal sticks to the floor, is that the clutch going bad or the fluid temperature problem, or both? If I replace my clutch will it not get stuck to the floor anymore?

Replace the clutch and the fluid. Give Peter a call and he'll fix you up :cool:

My question is, when the pedal sticks to the floor, is that the clutch going bad or the fluid temperature problem, or both? If I replace my clutch will it not get stuck to the floor anymore?

If your clutch is slipping, it will make things really hot in there......