Clutch master cylender question

[DVolk]

Ok this should possibly be on the conversion section but lately there is no one on it nor does any one answer and its concerning a gen 1 truck build . On my 85 build im doing i might have ran into a snag but i need to do more measureing to confirm it . On the fire wall the electricle plug is in a diffrent location by a inch or so . So im thinking this is going to come into play with the clutch master cylender . So i have a question or two that i need help with .



1. Does any one know if a gen 2 clutch master cylender will work on a gen 1 truck ? , does any one know the the with of the mounting plate and what type of renforcement inside of the cab is needed ?

i think a 4" square plate inside of added material would fix this .



2. other question on the gen 2 trucks 94 to 981/2 are the wireing plugs smaller in size , i know there is 2 or 3 on the gen 1s that are the same but im more so refering to possibly get rid of the large square wiring block since the engine im going to use is a 94



3. does any know and or have a gen 1 inside cab clutch master cylender mount some one welded the one i got so that one is useless now

 

[PToombs]

The hole for the bulkhead is definitely in the way of the clutch master. I swapped and put an 86 cab on my 92. I cut out the old firewall oversized and then cut the donor cab and fitted the panel in. I made the inside seam right on the support for the steering column so I could weld all 3 pieces together. I can't help with #1 and 2, but on the welded bracket, if you aren't using the cab, you should be able to cut out the column support bracket and then remove the clutch bracket easier out where you can get at it.

 

[DVolk]

I scored a after market race style wilwood / afco remote master cylender cheap on e bay so i thought i might see how it looks . Does any one know of a reason why it would not work ? the one i got is a 1" bore so that should be big enough there , ive also thought about a diffrent electricle bulk head , if push comes to shove i thought about maybe cutting the old fire wall then fitting over the old and may be bolting it ?, Any Ideas ?

 

[GCroyle]

DVolk,



Larger M/C piston diameter with the same stroke length and keeping the S/C the same diameter = longer release bearing travel. Possibly no problem, but there is one observation to consider. Your factory setup has a certain amount of reserve travel, this is dead travel as the pedal comes up off of the floor and is between floorboard and 1st hint of clutch engagement. If you keep the reserve travel about the same give or take, should be no issue. But it the pedal effort is a LOT more and you have a significant increase in reserve travel, the bearing is stroking a lot farther. If you can accept the release load, just consider a travel limit stop on the pedal somehow, no need to over stroke the system. Also (if the Wilwood) as you setup a PISTON PORT adjustable M/C suggest you always make sure after you are adjusted that you can easily compress the S/C by hand. Remove S/C and compress pushrod by hand. If you can't then the port is still closed and you need to readjust and make sure port is open with your foot off of the pedal.

 

[RSchwarzli]

For what its worth, I have used South Bend Clutch's 2nd gen hydraulics for both the crew and the 1990. Their system is actually a gen 1 adapted for a gen 2 even though they wont tell you that! The biggest difference is that the slave is facing the wrong way. Not an issue if you are using a 5600, a bit of an issue if using the g360.

As for STOCK dodge parts, that I dont know. Was just providing an alternative!

 

[DVolk]

Robert if your useing the 2nd gen style on your trucks , im assumeing with the 92 syle mount the twist and lock
what is the length of your push rod ? Does any one know what the gen 2 mounting flange measurements are ?
I can't get a good answer from any one on any measurements .

I called South Bend and there kind of rude on the phone . They say measure the distance of the fire wall to the cluch pedal im not shure how to do that and im not going to cut a hole and be screwed .

How do i set this "free Travel " isn't this set by the pressure plate ????

 

[GCroyle]

How do i set this "free Travel " isn't this set by the pressure plate ????

One or two pieces to the puzzle are missing, I'll try to fill in as best I can.



1. Bearing free play requires a return spring on the fork pulling it away from the clutch. Our slave cylinders have a spring inside the slave body that pushes forward against the fork and this creates the preload against the bearing. Bearing turns if engine is turning.



2. Two types of M/C designs have been used, piston port and a poppet or check valve type. 3rd Gen uses poppet/check valve and can easily be identified as follows. The supply of fluid going into the M/C body is almost inline with the discharge. There is a slight offset, about 1/2" or so, but not much. For piston port the fluid comes in at one end, piston closes off the port and it is discharged at the opposite end several inches away.



3. This "floating" release system accommodates the increase in diaphragm spring tip height due to normal wear resulting from the disc getting thinner. NOTE: Self Adjusting Clutches (G56 OE) stay at almost the stock height throughout their system life.



No matter which system, both have this in common and it is an easy thing to check if you are doing customization. At rest, foot off of the pedal there cannot be any hydraulic pressure in the system. If it had pressure, that means the release bearing has an additional force on it above and beyond the normal S/C preload spring force. This causes premature bearing failure and can actually reduce the clutches clampload. Easiest way I know to confirm that you have ZERO PSI at rest, after you are "done" remove the slave cylinder and just compress it with your hands. It will move the fluid from the S/C back up and into the reservoir, integral or remote piston port or check/poppet valve type.

 

[RSchwarzli]

Robert if your useing the 2nd gen style on your trucks , im assumeing with the 92 syle mount the twist and lock
what is the length of your push rod ? Does any one know what the gen 2 mounting flange measurements are ?
I can't get a good answer from any one on any measurements .

I called South Bend and there kind of rude on the phone . They say measure the distance of the fire wall to the cluch pedal im not shure how to do that and im not going to cut a hole and be screwed .

How do i set this "free Travel " isn't this set by the pressure plate ????

Yes, SBC says it wont work on a first gen. I always find it odd everytime I shift that I dont grand the trans if it doesn't work.


The rod length is easy. They send 3 of them! But all you use is the factory one. And one of theirs is the same length as the 1st gen factory one (the shortest... )

And yes. SBC supplies a twist and lock if you take the 2nd gen adapter off. Literally that easy!

 

[DVolk]

So they are rigged up on a addapter to put the first gen twist and lock to a second gen via a adapter ?
Do you have a measurement of this part ?of the mounting flange

 

[RSchwarzli]

Yes. Exactly.

Hmmm. I will have to see if I kept the adapter... . not sure I did.

 

[DVolk]

If you have the part number that will be a big help as well , and a measurement of that adapter or if you dont want it
id pay for the postage , it should go in a flat rate envelope if you have that in ontario ? It would be nice to see if i can just modify a stock part if at all possible , on your crew cab what was done to your fire wall a diffrent one welded on , something im not wanting to do

 

[HHhuntitall]

I used the one out of my donor truck, it simply unbolts off of the original steering column and can be bolted to your current trucks dash. You have to drill the hole through the firewall off the center of the clutch holder, then, and it's downhill from there.

 

[DVolk]

I know how it looks i can look at my 92 also the donor truck .

My issue is i have a 85 cab and Ma Mopar decided to move over the wire bulk head some time after 87 .

This is my issue im haveing , the way i measure the bulk head is in the way by about a inch or so with the 2 1/2 " hole that neeeds to be drilled .

 

[RSchwarzli]

I dont seem to have it anywhere Donovan. Im sorry. Without it I cannot send it or measure it!

And yes. My firewall was modified with a plate that lays overtop of the firewall with all the cutouts of the 93.

 

[HHhuntitall]

I guess I didn't clarify that that pic is of my '85 Crew. I moved the bulkhead over (outward) almost exactly 1", welding the piece I cut out of the firewall on the outside of the factory loom on the inside where there was a hole below the master cylinder. If you look closely inside you'll the shiny paint I burned when I tacked it back in.

 

[DVolk]

Rob, you say that there is a peice of sheet metal over your fire wall is it just anouther panel from a donor truck ?
or is it an actual peice of sheet stock made to fit ? is it bolted or welded on ?

HHhuntitall, So you moved over your bulk over a inch ? then welded the removed peice back in ?

Does any one have a master cylinder bracket they want to part with ? I have a 88 dakota that might have one but i doudt it would work

 

[RSchwarzli]

Mine is a custom made for application 1/16" thick, 8"x10" piece with the holes cut in using a 89+ firewall as the pattern. This way all aligns and you do not see the wrong holes hiding behind it.

 

[HHhuntitall]

Yes, on mine, I simply welded the cut out piece back in to keep there from being a huge hole.

 

[DVolk]

Rob, How was your custom peice mounted ?

 

[RSchwarzli]

I just used a few 1/4x20 bolts. Nothing fancy.