dieselfuelonly
Member
I put a new clutch in one of our C6500s. This was the one I got - https://www.phoenixfriction.com/p-4...k-topkick-66l-v8-diesel-81l-v8-gas-13-in.aspx - Worked great for just short of two months or so, then the other day one of the guys said the truck was stuck in gear when he tried to leave the lot. I managed to get it out of gear, and when I did I noticed it seemed like the clutch was not completely disengaging explaining why he was having such a hard time getting it out of gear.
This truck has a cable (no hydraulics) from the pedal linkage that pulls the lever that moves the fork to push the release bearing against the pressure plate fingers. I checked everything I can think of to make sure nothing was binding. Cable didn't seem like it was stretching. Release bearing is separated slightly off the pressure plate fingers when the pedal is out so it's not spinning all the time and wore out already.
This is where stuff gets weird - I found that if I disconnected the cable from the fork lever and moved the lever back and fourth a couple times (moving the release bearing back and fourth way further than it would normally be) , then hooked it back up, when I would push the clutch in and start the truck (and kept the clutch pushed in) I could shift it into any gear no problem.
Then, as soon as I let the clutch out in neutral, then pushed it back in to try to shift it into a gear, no dice unless I really forced it in gear. I swear you feel more pressure at the bottom of the pedal after the initial push/release.
If I started the truck up again with the clutch pushed in a second time, no luck, wouldn't go in gear. But every time I would get down under the truck and wag the release bearing around I could get it in gear no problem on that initial start.
I pulled the trans back out today separating it at the bellhousing (pulling the housing on these trucks is more involved since its used as a mount for the rear of the engine AND the transmission) and to my surprise the release bearing looks fine. Fingers on the fork look fine. I don't see anywhere there are signs of the bearing getting stuck. No broken fingers on the pressure plate.
The only thing I can figure (and this is really stretching it here) is the clutch disk can slide freely on the input shaft when the engine isn't running, but once the load on it is there as the engine spins it's getting stuck on the input shaft and is staying jammed up against the pressure plate? But that wouldn't explain why when I pull the cable and wiggle the release bearing around it works fine on the first try.
Any ideas? Really scratching my head on this one.
This truck has a cable (no hydraulics) from the pedal linkage that pulls the lever that moves the fork to push the release bearing against the pressure plate fingers. I checked everything I can think of to make sure nothing was binding. Cable didn't seem like it was stretching. Release bearing is separated slightly off the pressure plate fingers when the pedal is out so it's not spinning all the time and wore out already.
This is where stuff gets weird - I found that if I disconnected the cable from the fork lever and moved the lever back and fourth a couple times (moving the release bearing back and fourth way further than it would normally be) , then hooked it back up, when I would push the clutch in and start the truck (and kept the clutch pushed in) I could shift it into any gear no problem.
Then, as soon as I let the clutch out in neutral, then pushed it back in to try to shift it into a gear, no dice unless I really forced it in gear. I swear you feel more pressure at the bottom of the pedal after the initial push/release.
If I started the truck up again with the clutch pushed in a second time, no luck, wouldn't go in gear. But every time I would get down under the truck and wag the release bearing around I could get it in gear no problem on that initial start.
I pulled the trans back out today separating it at the bellhousing (pulling the housing on these trucks is more involved since its used as a mount for the rear of the engine AND the transmission) and to my surprise the release bearing looks fine. Fingers on the fork look fine. I don't see anywhere there are signs of the bearing getting stuck. No broken fingers on the pressure plate.
The only thing I can figure (and this is really stretching it here) is the clutch disk can slide freely on the input shaft when the engine isn't running, but once the load on it is there as the engine spins it's getting stuck on the input shaft and is staying jammed up against the pressure plate? But that wouldn't explain why when I pull the cable and wiggle the release bearing around it works fine on the first try.
Any ideas? Really scratching my head on this one.
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