Slave Cylinder Saga

1000hpOdyssey

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I recently installed a McLeod twin disc Meba lined clutch to get the truck ready for the blower that Justin will be installing shortly. Actually, my time line on installing the McLeod was advanced due to my Centerforce piece of crap failing after less than 2,000 miles (and no drag racing). When the Centerforce was installed I also installed the upgraded Viper slave and master cylinder. I thought that the upgraded Viper slave and master would work just fine with the McLeod since Dom had ran that set up with his monster truck. I was not as lucky as Dom. After less than 100 miles the upgraded Viper slave went to pieces. See attached pictures. The plastic collar that holds the throw out bearing must have overheated causing the plastic to get brittle and break into 10 to 12 pieces. The shim at the back of the candle stick, and the candle stick itself practically welded itself to the shaft.

I figured that the McLeod was just too stout for the upgraded Viper slave so I ordered the McLeod slave. Big mistake. The McLeod slave is a bear to space properly. :mad: It is not attached to the transmission and the only thing that keeps it from spinning is the hydrolic lines. The spacing is done with a screw out collar that does not even have a set screw to keep it where you place it. After being off and on several times and speaking with McLeod, they said you need to change out the master cylinder to make it work properly because the fluid hydrolics of the McLeod slave are different from the Viper slave. I then spoke with several highly competent mechanics that confirmed that even the slightest change in volume of hydrolic fluid, length of hose ect. will change up the pressure in the lines. Long story short, I blew out one of the O rings in the McLeod slave trying to make it work and never got it right. :mad: IMHO the McLeod slave should be avoided, unless you have a lot of time to play around with it and do not mind taking the transmission out numerous times. IMHO, you would also need to cut an inspection hole in the bell housing so you could see what was going on during the set up.

Final solution, a friend of mine, Greg Good (Greg Good Cylinder Heads in Houston) made a new spacer and a new part to replace the plastic collar in the upgraded Viper slave. See pictures attached. This part is pretty trick. Greg machined it out of aluminum. It has multiple grease grooves on the inside of the collar with an O ring on the end to keep the grease from coming out. It also has a small lip on the end to keep the throw out bearing from coming off. He also machined a proper spacer with grooves on both sides to seat properly against the transmission and the candle stick. We also did away with the Dodge spring. It seems like all it does it keep the throw out bearing and plastic collar up against the clutch fingers to keep the rattling down. With a precision made aluminum part, you do not get any rattling, therefore, you do not have to have the throw out bearing resting against the clutch fingers. That just wears them out prematurely.

The piece works great. Shifts great. Stock pedal height. A little stiffer than stock, but that is due to the McLeod clutch. :rock: :rock:

Sorry I could not get the pictures to line up in order. You guys will just have to go through them out of order. Hopefully you will be able to figure things out from the narrative description. I attached a lot of pictures. I hope they made it through the server and got attached. I know this thread is worthless without pictures.

Special thanks to Greg Good for bailing me out of this jam.
 

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Is he willing to sell this in a kit form? I'm pretty sure a few of us would be interested.
 
Chuck B said:
Is he willing to sell this in a kit form? I'm pretty sure a few of us would be interested.

I do not know. He did this on a lathe as an R&D project and as a favor to me, but it was very time consuming. He likes doing R&D on Viper stuff (including Viper trucks). This would need to be done on a CNC machine to be economical. He also built my motor and did some trick stuff, including some special mods to address the oiling problems on the rod journals, and you would be surprised to see how much he got my heads to flow. :rock: :rock: :rock:
 
If he was willing to make one more someone like Stinker could drop it off to someone who can convert to CNC language.
 
FATJACK said:
I would order the piece today, having the same problem.

IMHO anyone using a stout twin disk racing clutch with the upgraded Viper slave should consider modifying the Viper slave to get rid of the plastic collar. It is a problem just waiting to manifest itself. When it goes it really does a lot of damage, I am lucky that I was able to salvage the shaft by filing it smooth and polishing it with sand paper. When it blew I was slowly approaching a toll booth. I am glad it did not let go under acceleration.

Greg Good came up with a heck of a fix for this weak link. I wish I had a spare to send you, but I only have the one. I can't speak for Greg but since I watched him make it I can say that it is so time consuming that it is not economically feasible to make them on a lathe.
 
I'm pretty sure what happened to the Viper slave was due to it not being indexed, or centered, on the transmission. The input shaft welded itself to the inside of the snout on the slave and broke it off, and the plastic throwout bearing holder was collateral damage. There was a flat shim behind the slave that did not keep everything located. You can see in the pics that the new part has a lip that slips over the transmission, and a stepped down nose that slides up into the back of the slave. That prevents contact between the input shaft and the slave.

The throwout bearing holder is self explanatory in the pics. It slides on the snout of the slave, and holds the throwout bearing. There isn't a pic to show it, but on the bottom of the slave is a small machined surface that is perfect for installing a set screw. I put a set screw as close to the font of the snout as possible, and machined a keyway in the throwout bearing holder, so it cannot rotate and cause damage to the piston in the slave. The holder can only move in and out, not rotate.

The key dimension in doing this is to get the clearance between the throwout bearing and the fingers on the clutch set to .100" - 125". John and I measured the distance from the transmission mounting flange to the fingers on the clutch at 2.600" (approximately). We then made sure that the throwout bearing was 2.500" from the face of the transmission, putting us at "about " .100" clearance.

A nice touch would have been to had the holder Type 3 hard anodized.

I don't know if this setup with last forever, it should last a good while. Well just have to see.

But anyway, the two main points are; if you put a shim/spacer behind the slave, make sure it isn't just a "flat washer" type, but one with a lip on the back and a step on the front, to keep the slave perfectly centered. And set the throwout bearing to clutch finger clearance to about .125".

Greg
 
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GREG, please make us a kit.. There is quite a few of us running upgraded viper slaves and still having issues with slave. It looks like you've really developed a nice concrete solution.
 
The thing is, every truck could be different with regards to where the fingers on the clutch sit, especially with different makes of clutches. That's going to change how long the throwout holder needs to be.

It's way too time consuming to churn these out one at a time. I would think a run of these could be done on a CNC machine at a decent price.

I didn't make a print of these parts afterwards. John and I made it flying by the seats of the pants, thinking of things to do while machining it. After it was done John had very little time to get everything out to the installer. Minutes counted.

I'm not a pro machinist by any means, and a guy doesn't have to be to make this part. If you know someone with a lathe large enough to chuck onto a piece of 5" aluminum round, he can do it. I'm not saying I don't want to do it, but it is VERY time consuming.
 
We only need one... and I've got over 100K miles on my original stock clutch & parts If there was anyone who should be saving for clutch upgrade I don't know who better than me! :rock:
 
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The thing is, every truck could be different with regards to where the fingers on the clutch sit, especially with different makes of clutches. That's going to change how long the throwout holder needs to be.

It's way too time consuming to churn these out one at a time. I would think a run of these could be done on a CNC machine at a decent price.

I didn't make a print of these parts afterwards. John and I made it flying by the seats of the pants, thinking of things to do while machining it. After it was done John had very little time to get everything out to the installer. Minutes counted.

I'm not a pro machinist by any means, and a guy doesn't have to be to make this part. If you know someone with a lathe large enough to chuck onto a piece of 5" aluminum round, he can do it. I'm not saying I don't want to do it, but it is VERY time consuming.
 
Testing the new Slave Cylinder

Drove the truck all weekend with the "Good" modified slave in stop and go traffic. Shifts great. May be my imagination, but I seem to be able to hit third much easier than ever before. :elefant: Can't wait for Justin to install the blower now.
 
If there is a kit in the future I will take one. My slave is in bad shape right now too. The plastic is broken and melted right now.
 

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