The Stovebolt Site Forums The Shop Area Driveline SM420 shifting problems

So here's the backstory:

I have a 1954 Chevy 3100, which had a 235 in it. I swapped the 235 for a good running 230, and replaced the 3 on the tree with the SM420 (I know it has the same final gear). Before I put the 230 in, I put a new clutch kit on... disc, pressure plate, throwout bearing. Then it sat for 3-4ish months over winter as I worked on other things. I got the brakes sorted, got the driveshaft in... ready for a short test drive down the road... or so I thought...

I can't get it to go into any gear with the engine running and the wheels on the ground.

Engin off, no problem... shifts smoothly. Engine on, with the rear jack up... same thing... shift no problem.
Crawled under the truck to watch what happened when The clutch pedal was depressed. The throwout bearing comes in contact, and presses against the pressure plate, the pressure plate DOES release some of the pressure on the clutch disc, the clutch disc doesn't come off the flywheel at all. I CAN see some movement between the two layers of the clutch disc.

Its almost as if the clutch surface has frozen onto the flywheel over the winter?

Throw some ideas at me!


Thanks fellas

How much free play does your pedal have? Have you tried putting the truck in gear with the engine off to see if its still grabbing? Note: probably a good idea to take the coil wire off so the engine won't start when you try this.

The pedal has about an inch of free-play before I can feel it press against the pressure plate. I have tried putting it in gear, and then starting the truck (making sure to be in a clear area and not run into anything). The truck grabs and goes and wont shift out while the engine is on and we're moving

THESE are all farm tested practices:
Yes, the disk has set to the flywheel. TWO Person job
1. IGN OFF:have someone pull you in high gear. once you get going shove in the clutch and the effort to turn the engine should break the clutch loose from the flywheel.
2. Ign off in high gear:rock the truck back and forth while someone holds the clutch down.
3, More dangerous method, start in neutral, hold break and clutch down and grab high. Engine may die a couple of times. mike

If I was doing it I would adjust the clutch and take all the freeplay out. Then give it a try. Once it loose then re adjust the clutch. By taking out the freeplay you will get a little more movement on the pressure plate when you push the clutch in.

Got it all sorted out! MtneerMike's suggestion #1 was the ticket! Thanks fellas... never had that happen before (although I'm still new to the old truck world)