Hi, I just finished up a 5.3 swap into my 95 rcsb with a factory nv3500. I can shift the truck with the motor not running but not when its running. if I start it when it's in gear it isn't grabbing hard enough to move the truck but its obviously turning the transmission input shaft a little bit. I double checked the slave cylinder and it looks like it is working properly and i'm getting good movement from the throw out bearing.

I used the sachs 1050 flywheel and a clutch for my 95 5.0 and nv3500. I also used the special pilot bearing and it slid on the transmission input shaft nicely before I pressed it into the flywheel.

anyone have any ideas? weld an 1/8 inch to the slave cylinders push rod?

thanks

 

1st gear, level ground, clutch pedal down, engine held at 2500rpm, does the truck move? If yes, you need to troubleshoot what's dragging.
Clutch should be the right height, but since he engine and flywheel changed, seeing if the slave cylinder needed a shim still applies to the CSC slave models.
The trans. pilot tip should be just right with the big pilot bearing, but just in case, you can space the trans out with washers between it and the bell to troubleshoot.

 

the truck wouldn't move with it in gear, it was just barely dragging. I think i may have gotten it sorted out though. I found a mold ejector pin that was about a 1/4 inch longer then the slave cylinder pushrod and bolted it up with that in it. It was still hard to get it in gear and the rear wheels would spin in the air as i tried putting in gear but at least now it would go. I dropped the truck to the ground and rolled it into the street and just started driving it, it took about 50 gear shifts before i could get the transmission in gear from a dead stop. today i'm going to put the original pushrod in and see if it will shift with that one now. I've replaced alot of clutch's and have never had this problem before. I'm suspecting the clutch just may have needed a little worn off and the new flywheel just smoothed out a little bit to stop the dragging.

so now I have a new question, when the slave cylinder goes in it is pushing on the fork before the slave is fully seated against the transmission. is it normal for the throw out bearing to be running against the pressure plate fingers all the time on this tranny? it's not moving the fork but it has spring pressure pushing the bearing against the pressure plate.

 

Nope, the throwout should not be touching. It's going to wear out very quickly if it does.

 

Will the truck roll when in first gear and no pressure on the clutch? (Engine off.. )
If the TO bearing is riding on the cover release forks they will fail eventually.

 

I don't know on your question. Old stuff ran an air gap.
New concentric throw out bearings are lightly loaded against the PP with a spring, and spinning with it. Look at a diesel of the same year truck, or the LS cars' slave cylinders.

 

thats what I thought, the throw out bearing that I removed was going out too but i'm not sure how long it was in there. I have only put about 2000 miles on the truck since I bought it.
I can't understand how the slave cylinder won't put pressure on it though, the push rod is spring loaded. during my diagnosics of my shifting problem I made a tool to block in the slave cylinder all the way and depressed the clutch pedal and had a good firm pedal. I also held the push rod in my hand and had a friend depress the pedal while I put the push rod in different positions and everytime it would immediately push back against me. it is almost like it is designed that way to take up the wear in the clutch disk. otherwise if it was a set amount of travel it would require shims I'd think.
but if something is wrong i guess it would explain why the syncros are junk in the first 3 gears and the throw out bearing being junk.
I wasn't able to drive it today since I was trying to figure out why the pcm wont command my fans on. I'll go back to testing/diagnosing the clutch tomorrow.

thanks for all the input

 

what exactly did you do to fix this issue? I’m having the same exact issue!

 

Me three. 95 k1500 nv3500. 08 4.8 with 6.0 flywheel and still using the old 305 clutch. I know the 96 and newer have internal slave cylinders. Do they have more travel? Any help would be welcomed