Anyone convert a Muncie M21 to an externally mounted hydraulic slave set up?

[FLYNAVY53]

I’m looking to use a Tilton or Wilwood pedal assembly in my Corvette for a number of reasons which will require converting to a hydraulic slave cylinder for the clutch. I’m looking for any tips, guidance, etc. from anyone who has done a similar conversion.

thanks!

[68sixspeed]

I did it years back on a Richmond 6 speed which is very similar, McLeod made a hydraulic throwout bearing, I still have that but I’m not sure if it fits a Muncie. The McLeod was self adjusting where some of the other circle track hydraulic throw out bearings were more universal and needed shims. I have a m20 here I’ll see if it fits, might take until the weekend to dig everything out. Dan

[andrewb70]

I just installed a Tilton 6000 bearing on my GTO with a Richmond 6 speed. Installation would be identical as a Muncie. Works well!

Andrew

[FLYNAVY53]

Thanks for the input guys. Everyone I've talked to has recommended going with an external slave cylinder set up over a hydraulic throw out bearing. Any thoughts? I've found a couple different set ups that use a Tilton cylinder, along with a bracket that mounts to the bell housing and a new fork. I guess a lot of the Cobra kit car crowd run this set up.

[andrewb70]

Every new car uses a concentric internal hydraulic TOB. If you use a quality product, like the Tilton, you'll have zero issues. They are also fully refundable with a simple O-ring kit.

Andrew

[FLYNAVY53]

Thanks Andrew....sometime its hard to decipher on the Corvette Forum what does/doesnt work, and what is just a bunch of old guys being resistant to change.

[andrewb70]

Thanks Andrew....sometime its hard to decipher on the Corvette Forum what does/doesnt work, and what is just a bunch of old guys being resistant to change.

No doubt they think an external slave is easier because the transmission has to be pulled if an internal slave fails. While this is true, the odds of failure are low. My old Quarter Master unit was starting to fail only after 5 years of use, most likely due to a lack of use...

The TOB in my little Mazda (ford ranger) truck is original from 1999 and has 120K miles on it.

The concentric internal bearings eliminate the fork, which is a source of slop, and offer better pedal feel.

Andrew

[FLYNAVY53]

The concentric internal bearings eliminate the fork, which is a source of slop, and offer better pedal feel.

Which in addition to better pedal ergonomics and correct ratio for a manual brake system is the whole point of this exercise.

Thanks!

[andrewb70]

Which in addition to better pedal ergonomics and correct ratio for a manual brake system is the whole point of this exercise.

Thanks!

Exactly! I don't know about the Corvette pedals, but Cougars and Mustangs are notorious for having sloppy pedal shaft bushings. I replaced mine with a kit that uses roller bearings. This made my whole pedal assembly very smooth and solid, much like a new car. I'd look to see if there is an option like that for the Corvette pedals.

Andrew

[FLYNAVY53]

Cool video. The problem with the Vette isn't so much the slop in the assembly (although that is present) as much as the pedal placement itself.





As you can see, the brake and clutch pedal are almost 9 inches off the floorboard and 5 inches closer to the driver than the gas. This makes heel-toe downshifts impossible (even with my size 13 water-skis) and panic stops are borderline unsafe. You need to physically lift your entire foot off the floor and onto the brake pedal. You can also forget about driving in flip flops with this set up. Additionally, the brake pedal ratio is somewhere in the neighborhood of 4.5:1....functional for a boosted set up, but insufficient for a manual brake system. The Tilton and Wilwood assemblies are both around 6:1 which should be about perfect for the system I'm currently running. The hard part is going to be modifying the factory pedal bracket to mount the new pedal assembly while retaining all of the factory attachment points. Since the car is obviously fiberglass, everything is anchored to the metal dash support structure and not the firewall.

[vette427-sbc]

I used to run an external slave on my Muncie... it flexed the bracket, and shortly killed the slave from the consistent misalignment. I would use a hydraulic TOB in a second.

[showdog75]

Andrew, your my hero. Anybody that drags there welding table in the house when the queen is gone and fires up the tig rig has a special place in my heart, lol.

[andrewb70]

Andrew, your my hero. Anybody that drags there welding table in the house when the queen is gone and fires up the tig rig has a special place in my heart, lol.

Hahaha!

Thank you, Sir! It was a fortune series of events that allowed it all to happen. I not only did the pedals, but I also modified my steering column to install the Prius electric steering.

Andrew

[FLYNAVY53]

Did some measuring in the car, and essentially rendered the argument irrelevant. On the Corvette, there is no room to mount an external slave. Due to the confines of the trans tunnel, the stock clutch fork actually bends back towards the front of the car to the point where it is right next to the bell housing bolts you would presumably mount the bracket and slave to.







So in the tradition of good old fashion project creep, I suppose if I'm going to do the pedals, I'm into it for the hydraulic bearing....and might as well do a new clutch, and the removable cross member while I'm down there....right?

Any recommendations on which Tilton bearing to use on a stock Muncie M21?.....or a clutch recommendation for that matter?

[andrewb70]

Did some measuring in the car, and essentially rendered the argument irrelevant. On the Corvette, there is no room to mount an external slave. Due to the confines of the trans tunnel, the stock clutch fork actually bends back towards the front of the car to the point where it is right next to the bell housing bolts you would presumably mount the bracket and slave to.







So in the tradition of good old fashion project creep, I suppose if I'm going to do the pedals, I'm into it for the hydraulic bearing....and might as well do a new clutch, and the removable cross member while I'm down there....right?

Any recommendations on which Tilton bearing to use on a stock Muncie M21?.....or a clutch recommendation for that matter?

You need the same one that I used. Look in my GTO thread. I have pictures of the bearing with a part number. Link in my signature. It'll be in the last couple of pages as this was a recent project.

Andrew

[FLYNAVY53]

Thanks Andrew!

[FLYNAVY53]

Andrew, I read back through your entire GTO thread....very impressive build. The part number I pulled off the Tilton bearing in your thread was 60-6101. In talking with the Tilton tech support, he thought I needed 60-6102 for the Muncie? I'm assuming the Muncie and your Richmond box have the same input shaft size, thus would use the same bearing? He stated he was under the impression that the Muncie had a 1 1/8 shaft and would require -6102. Obviously at the moment, I dont have the gearbox out to measure.

Thanks

[andrewb70]

Andrew, I read back through your entire GTO thread....very impressive build. The part number I pulled off the Tilton bearing in your thread was 60-6101. In talking with the Tilton tech support, he thought I needed 60-6102 for the Muncie? I'm assuming the Muncie and your Richmond box have the same input shaft size, thus would use the same bearing? He stated he was under the impression that the Muncie had a 1 1/8 shaft and would require -6102. Obviously at the moment, I dont have the gearbox out to measure.

Thanks

The Muncie and the Richmond have the same input shaft diameters and more importantly the bearing retainer snout diameters are the same.

Andrew

[FLYNAVY53]

Perfect, thanks!

[FLYNAVY53]

One more question....what size master cylinder are you running with that bearing?