Clutch slave spring mount

[TRybas]

Does anyone have a picture or diagram of the clutch spring mount. I see no good way to attach it, can’t find anything in the manual or the forum. I assume a bracket got lost in the shuffle. If that’s the case I’m in the market if anyone has an extra.

Thanks, TJ

[Funky61]

Do you mean this one?

[TRybas]

Yes thank you. My spring has a much larger diameter and does not fit to that hole in the frame. I assumed a bracket attached by that frame hole. And the spring mounted to that.

[Funky61]

Your welcome TJ

[James]

Here another link:
https://6066gmcclub.com/showthread.php?t=49176&highlight=clutch+spring

[Jim A]

As long as you are spending time on your slave cylinder, would you check to see if the piston travels all the way to the snap ring?
I've finished rebuilding my clutch ('60 1500) but still can't get an adjustment setting that gives me free play and release.
That is, when I get enough travel to let the disk to turn, the throw out bearing is under a lot of pressure.

[Jim A]

There is a 1/2" +/- hole in the frame just opposite the inlet end of the cylinder that woks well.
I think we used the inlet hyfraulic line for a while, too.

[TRybas]

Jim. Mine was at 7/16th before it reached the snap ring. I tightened up the slop in the peddle (extend the pushrod at the master cylinder) and it now reaches the snap ring under no load. Under a load it still does not reach the snap ring. No good way to measure that distance.

I had my sm420 completely rebuilt while everything was apart. New forks and synchros. I know they are clunky but I’m having a lot of trouble shifting. I’ve tried everything; running through the gears, double clutching, ect. And still have a terrible time getting into first and reverse. The only way I can do so without blood curdling grinding is by shutting the motor off. Anyone have any ideas or is that just the world we live in?

[Jim A]

That grinding in reverse and granny is what I began experiencing a few years ago and have been fighting ever since.
It is caused by the failure of the pressure plate to fully release the driven disc and the tranny gears continuing to rotate.
It can be "adjusted" away by lengthening the slave control rod to give the throwout bearing more movement, hence earlier and greater disc release.
This solves the grinding problem in the non-synchro gears, but at the expense of never fully freeing up the t/o bearing, making it in continuous contact with the release levers (or diaphragm) and turning continuously. Sort of like the worst "riding" the clutch possible.
Eventually the t/o bearing fails and takes the levers, the big main lever and the pilot bearing with it.
See my posts in related threads.
Clutches and parts are not available anywhere I could find and I had to replace the release levers with some I got from the trash barrel of a reman place.
I think I may have gotten one of two "long style" t/o bearings in existence from National through O'Reilly for about 70 bucks.
It has been a big job and one I still have not fully solved, with the lack of balance between free play and disc release still existing.
I still hope that the folks here have a fix.
Two things that don't help are "hydraulic clutches don't need adjustment" and "why don't you just put a 12" clutch in it."

[AZKen]

We all know we have to bleed the slave don't we? Just thought I would mention.

[TRybas]

Yes. We all know.

Thanks Jim. Squeezed in a quick ride after cleaning up the travel last night; left a tiny bit of play so the throughout is not engaged at the rest position but it’s 100 percent better. Going to get some miles under the belt and may try to tighten it up a bit more so the slave reaches the snap ring while under load.

[Jim A]

Ken: We have bled the system everyway we can and do it every time we start over trying to get enough travel to release the pressure plate while trying to leave free play for the throw out bearing.
Do you have a special or favorite technique?
Thanks

[Jim A]

We finally found a sweet spot yesterday where the two necessary settings exist. It is a small one and perhaps fragile, but works.
Even though I have owned this truck for over fifty years and have never had anyone work on any part of it, I have a feeling that the interior clutch linkage is not stock.
As it is, the upper control rod runs out of threads long before it pushes the master piston half way in or less. I have a 1" extension on the end (inside the piston) that barely gives enough movement.
What would be helpful is if any of you have the opportunity to look at the geometry
of the clutch pedal arm and the control rod arm. Mine seem almost parallel. This means the rod starts movement forward too far back to reach the master cylinder.
If it is supposed to be maybe 30 degrees or more advanced of the pedal arm. it might work better.
The clamp system for the right end ( the control rod end) is not worn and clamps tightly. The other end of the connecting shaft (pedal end) has a weird fresh looking welded blob making the position. Fresh looking as in fifty years!
This is convoluted post, but if makes sense, please let me know your ideas.

[Jim A]

It looks like that was the problem and a modified top control rod clamp seems to have made the fragile fix solid.
Details on request.

[Jim A]

I learned yesterday that the counterweights on the internal clutch levers/fingers are to increase the pressure plate squeeze on the disc at higher RPM's. They work centrifugally.
Here is an interesting discussion on a good website:
https://ramclutches.com/clutch-university-chapter-2/

With the trouble I have had in getting free play at the t/o bearing, I wonder if this action will reduce it.