Despite nothing about this being LS or t56 I really feel this is the correct place to ask this question as I believe it to either be a hydraulic problem or a clutch selection problem that is equivalent to a SBC to T56.

Heres what Im working on:

1994 Chevy c1500.
2pc RMS 355 w/ 168t flywheel.
2000 Chevy s10 NV3500 w/ that same internal hydro throwout bearing as t56
Ford f350 7/8s master with homebrew adjustable rod
Hays Street/Strip clutch for standard small block chevy IE mechanical/fork style push clutch setup


Little history on whats taken place. Installed trans with stock master and -4 AN line. Clutch wouldnt disengage with the pedal down. Upgrade master cylinder to the 7/8s unit listed above w/ adjustable rod. Clutch disengages perfect, little adjustment, PEDAL HAS NO PRELOAD ON MASTER. So I think great, problem solved and go for a drive. Anytime I give it more than a tiny tiny bit of gas it just starts to slip to holy hell. As said brand new clutch, flywheel was cut, everything was cleaned and done proper.

So now Im trying to figure out my issue. I stick a boroscope in the bell and have the wife actuate the clutch. Clutch down, disengages great, release pedal pressure plate returns the bearing but it doesnt seem like its returning it enough...

Is it possible for the spring on the throwout to be engaging the clutch fingers too much? Could the slave be stuck at this extended point its returning to and not be fully collapsing causing the clutch to not fully engage? Did I just really goof by assuming a typical pressure plate was going to work with the HTO and really just need a shallower pressure plate?

I cracked the bleeder with the clutch engaged to see if maybe the master wasnt allowing fluid to completely return and there was no change, that doesnt seem to be the case.

And just for the record Ive had zero issues with bleeding. Im bleeding by gravity bleeding and then via a mightyvac from the top.

Please Help!

 

I don't have any experience with the 3500 trans but have swaped sticks into a few automatic cars over the years some requiring custom fab clutch pedal assemblies.

it sounds like the slave is keeping some pressure on PP.

since you harvested the 3500 might need to get a replacement clutch for the S10 as maybe that PP would sit slightly lower than the SBC HAYS. maybe just look at one at parts store and measure its height vs yours

is engagement very close to top of pedal?

 

Pedal engagement is spot on. The rod for the master has free play and the master is 100% disengaged. I actually found my old hydro throwout that came on the trans and collapsed it. After putting the boroscope in the trans again Ive come to the conclusion that the hydraulics are functioning fine and the HTO is 100% collapsed. The slave is simply bottoming out before the very tall pressure plate of the hays clutch can engage 100%.

Since Im into this clutch for $340 I started thinking outside the box with an older friend of mine. Hes been building hotrods for longer than Ive been alive. Based on the fact that the truck is drive able the preload caused by lack of space has to be super minimal. We're both thinking that using a block plate between the trans and engine would open the gap up enough to give the pressure plate the room to engage since it will add about an 1/8 inch between the slave and clutch, basically the exact opposite of shimming the HTO. Its either this or search for a shallower after market HTO. Im going to opt to try the block plate since it could possibly save me from pulling the trans all over again.

I plan on testing said concept by shimming the trans off the engine with some machine washers before I invest too much money or time into this idea. Ill take it down the driveway and see if it still slips and then replace with a block plate if it fixes it. The other thought is the pressure plate is simply defective and doesnt apply enough pressure.

 

spacing the tranny back with some washers 1/8" would effectively place the TO bearing further away, if that works than make a plate. only other direction to go is machine off .250 on backside of FW where it bolts to crank.....if there is enough material and there is enough space between FW & block. might need to shim starter if FW moves closer to starter though??

is the Hays clutch for a 2000 S10?

I would think a year/model specific clutch for the 2000 would work so compare whatever parts store replacement clutch is to yours in terms of PP/Diaphram height.

If the 1/8" space deal works it should be no issue as input shaft end and splines are long enough to allow that amount of spacing

I have a T56 swap into a 96 B Body with a McLeod Twin clutch. Had to shave off .250 from the clutch pivot stud to make it work. Stuff happens when you do these kind of drivetrain mods especially when parts are from diffrent model/year vehicle or your car was never manufactured from factory as stick cars like mine

worth it when you get it sorted out.

 

The problem with the correct clutch for the transmission is that the 4.3 flywheel has a different bolt circle than the typical SBC clutch bolt circle. I could probably go with an off the shelf clutch for a 305/nv3500 from a 96-98 C or K1500 as that is an internal hydraulic throwout nv3500 with a small block.

Like you said you could make the space up in other areas as well. I could probably even have 1/8 an inch cut off the flywheel depending on tolerance thats acceptable or even seek out and aftermarket thinner one. At the end of the day Im trying to get the thing back running w/ minimal investment in both money and time hence trying to make this clutch work. Its a huge lesson learned for the future though.