Need hydraulic clutch conversion advise/guidance

[Oldguyinajeep]

I've finally had enough of spontaneous bell crank dislocation. It's hosed me on the trail at some serious moments, and I'm not going to wait for it to strand or kill me.

I believe instead of putting this together piecemeal, I'll simply buy a kit. I see that Novak and others have nice kits, which get good reviews from other jeepers. I'd appreciate input from the forum regarding experience with and opinions of the different kits.

Also, I have a couple of technical questions:

I've put a vacuum assist power brake system on, and am concerned about clearance on the clutch master cylinder. I can find one posting that seems to indicate that it's doable.

Second, it seems that some folks use a YJ clutch pedal which already has a stud for the MC connection. Some also install a shoulder bolt in their existing CJ pedal. I could do the fabrication, but don't know where to position the bolt.

Any suggestions would be much appreciated.

 

[tarry99]

I've finally had enough of spontaneous bell crank dislocation. It's hosed me on the trail at some serious moments, and I'm not going to wait for it to strand or kill me.

I believe instead of putting this together piecemeal, I'll simply buy a kit. I see that Novak and others have nice kits, which get good reviews from other jeepers. I'd appreciate input from the forum regarding experience with and opinions of the different kits.

Also, I have a couple of technical questions:

I've put a vacuum assist power brake system on, and am concerned about clearance on the clutch master cylinder. I can find one posting that seems to indicate that it's doable.

Second, it seems that some folks use a YJ clutch pedal which already has a stud for the MC connection. Some also install a shoulder bolt in their existing CJ pedal. I could do the fabrication, but don't know where to position the bolt.

Any suggestions would be much appreciated.

Glad to see your doing some of the homework.........this is important so that you understand some of the obstacles that will get in your way to correctly convert over to a Hydraulic clutch.

Will start with the Brakes the size OD of the booster can get in your way........some boosters bolted directly to the firewall , some used an adapter that moved the booster away from the firewall by about 4 inches , check your firewall most were either pre-punched or indented bolt pattern wise for the booster and the clutch master cylinder. During your year model the 4 cyl. GM Iron Duke was an option and had a hydraulic clutch. Looking at that system will help you with your install.

If you had manual non power brakes the ratio from the pedal push rod to the master will be about 6:1 with power that ratio needs to be reduced to about 4:1.........other wise the pedal will be touchy when applied........in some pedal sets the second hole is already there but it's the location of the master on the firewall that does not align correctly with the push rod.........hence the reason some applications used the offset firewall adapter I mentioned above.

Since you already have a clutch pedal that's good.

On the hydraulics this can be a little more complicated , But here is the basics in relationship between your clutch master & your clutch slave: "Large bore equals less pressure but more volume." and Small bore equals more pressure but less volume"
A larger bore clutch master 13/16"- 7/8" is normally paired with a smaller bore "3/4" clutch slave........this is done so that the amount of fluid volume being moved downstream is greater from the master which will increase the travel at the slave.

Keeping in mind your clutch pedal ratio should be near 6:1.

The Novak slave although expensive is the best on the market for several reasons......1) it has the ability to have about 2" of travel and 2) it is easy to build a bracket and is also rebuildable.
Not knowing what you have for an exhaust system sometimes the slave being mounted forward of the bell-housing may get into your exhaust........they do sell push and pull slaves so keep that in mind.
A normal clutch pressure plate needs about .400" to .700" of an inch of travel from the throw out bearing including free-play to fully release the clutch disc.
At the clutch fork retaining ball , inside the bell housing the ratio there between the ball and the tip of the clutch fork changes to 2:1 so in order for your clutch to work your slave has to move at least double the distance mentioned above.

The parts are out there and just need to be mixed and matched.......some that I cannot find I just fabricate or relocate. Keeping in mind that the mounting position of the slave may have to remain fluid do to travel within the bell housing until you find the correct permanent mounting position. Sometimes the Novak adjustable throw out bearing collar is also helpful.

Not an easy job to do it correctly , but once you understand the basic needs of the system it does become much easier.

I'm sure I have left some things out.........hope it helps you!

I included a few pictures doing just what your trying to do but in a early CJ5 .........Here I relocated the booster to be in the correct position to the pedal push rod and did the same for the clutch master to the clutch pedal. All different ways to get there , just have to pick your path!

 

[Lumpy Grits]

Please tell us more about this bellcrank issue.
I ask because, my Jeep that I have owned for 31+ years, has never had any such issue. I have replaced the internal nylon b'crank bushings a couple of times. I do use Heim joint linkage.
Most times the issue you speak of is due to bad motor/tranny mounts and such.
LG

 

[mtnwhlr]

I had one time in my 5 where when wheeling I came to a spot where the the right front wheel came way up in the air and it pulled one side of the z-bar out. When it came back down I pushed the clutch to change gears and had nothing.

 

[Petescj]

Please tell us more about this bellcrank issue.
I ask because, my Jeep that I have owned for 31+ years, has never had any such issue. I have replaced the internal nylon b'crank bushings a couple of times. I do use Heim joint linkage.
Most times the issue you speak of is due to bad motor/tranny mounts and such.
LG

I had it happen twice in my old CJ5 . I'm not a big fan of hydraulic clutches either so I was going to go with a high joint linkage kit for like $80 back then. Jeep got stolen before I could try it.

 

[Oldguyinajeep]

First, the problem:

After I installed the 1" body lift, I extended downward the body mount for the bell crank, approx 1", to keep it level. I confess that I never actually put a level on it, or took exact measurements, but it passed the eyeball test. I had also installed a Heim joint adjustable clutch rod, and lengthened it to a point where the clutch was working properly. No problems for several years.

Living in Kansas, I don't have the opportunity to wheel in big rocks a lot, so my hours are Limited to a week or so in Colorado. We've done some very rough trails, e.g., Blanca, without problems. But on the last trip, I was in a very rough and steep portion of Eagle Rock, when I pushed in on the clutch and the pedal went to the floor. I thought the push rod may have come out, but when I get underneath the jeep, I find the bell crank has popped of of the bell housing mount. The retaining clip is still in place, but the plastic bushing is distorted from the dislocation.

I put it back together, probably 3 times, or more, but it would dislocate when the pedal was depressed. So, time for a redneck fix. I took two combo end wrenches, and used them as spacers, on the body mount side, effectively shoving the bell crank over to the bell housing side. This actually worked very well, and I was able to get back to CO Springs without any problem.

Took it to a local 4x4 shop, who told me it was not uncommon for this to happen when cjs get twisted up a little on the trail. They confirmed that the motor and tranny mounts were intact, put new bushings in, and sent me on my way. Later the next day, on a rough section, it happened again. I broke out the wrenches, made the trail fix, and proceeded in this fashion for the next 5 days, wrenches dangling beneath my jeep, without a failure (see pics).

When I got home, and could get it in my shop, it was obvious that the skid plate was distorted (encounter with a boulder, see normal and distorted plates in photos), and the engine was angled slightly. I replaced the skid plate, re-checked the mounts, and thought I was good. Have been driving it occasionally for 8 months, on-road without problems. Then, last week, it dislocated again, on an absolutely benign paved road. That's when I started looking for answers.

A google search will show many cj owners who have experienced this problem. Like Lumpy, I've been doing this a long time and have never heard of this issue until it happened to me. That's why I'm writing this long narrative, and why I will detail the hydro conversion, if that's the way I wind up going. I think quite a few cj owners have done this conversion. I base this on the fact that companies have actually put together kits, including specific mounting brackets, expressly for this purpose.

In the meantime, I've fabbed a new body mount, moving it inboard about 3/8", and down about 1/4", to make it absolutely level. Is this enough to prevent further dislocation? That's the big question.

Now, regarding the hydro conversion:

Thanks Tarry99 for your reply. I have some additional questions and comments. My brake booster is mounted on a bracket that sets it forward of the firewall. Is this the offset adapter you referenced? Also, there is a punch out on the firewall, so I'll know the proper position. I only have the original clutch pedal. Do you think it's easiest or best to just get a YJ pedal, or should I drill and shoulder bolt my original? Also, I didn't get your pictures. I'm wondering if others on the forum see them, and if so, why I'm not.

I think it's telling that a couple of our fellow jeepers mention that they've had this happen. I'll hopefully get a little more input. I'll definitely detail the hydro conversion, if I go that way, and it's looking ever more likely that I will.

 

[Oldguyinajeep]

Tarry99. I see the photos now. thanks

 

[Lumpy Grits]

That POS, OEM skid plate is the 'root' of many issues. The other issues are the engine & tranny mounts. One of the reasons I went with M.O.R.E. engine mounts some 20 yrs ago, when they first came out.
I too run a 1" body lift with my mechanical clutch. Will have one wheel in the air on a regular occurrence when jeep'n.
Have you done a in depth inspection of your frame for any issues that could be part of the linkage failures.
THX for the pictures!
LG

 

[Oldguyinajeep]

As I do further research, I have encountered another potential snag. In looking at various kits, I find that PartsMike's website states that hydraulic setups do not work well with performance heavy duty clutches and pressure plates.

HYDCL00SS HYDRAULIC CLUTCH KIT CJ AND UNIVERSAL

They say to use only stock parts. This seems counter-intuitive, as many race cars use a hydraulic clutch set-up. Any opinions about this?

 

[Oldguyinajeep]

Agree the skid plate is a POS. Actually looked into some robust (and expensive) aftermarket replacements. Is this a mod that you've done, and if so, which did you go with? Also, explain why you feel the M.O.R.E mounts make a difference. One mount may be more durable than another, but unless they are broken, shouldn't they all hold the engine in the same position relative to the frame/body?

 

[Lumpy Grits]

That is for multi disc type clutches.
Your C/F would not be an issue.
C/F uses LUK componets.
LG

 

[Lumpy Grits]

Agree the skid plate is a POS. Actually looked into some robust (and expensive) aftermarket replacements. Is this a mod that you've done, and if so, which did you go with? Also, explain why you feel the M.O.R.E mounts make a difference. One mount may be more durable than another, but unless they are broken, shouldn't they all hold the engine in the same position relative to the frame/body?

Look at a MORE Jeep engine mount and then the OEM style. Much less movement and far tougher/lasting design.
https://www.mountainoffroad.com/jee...motor-mount-kit-pre-99-cj-with-amc-6-cyl.html

Do you have the torque arm mount on your tranny mount set-up?

Here's the skid-plate I use. It's one 'tuff' SOB!
Throttle Down Kustoms TUBE SKID - Throttle Down Kustoms Custom Skid plate for 76-79 Jeep CJ - Quadratec

LG

 

[Oldguyinajeep]

I have a Center Force clutch and pressure plate. Nothing radical, but heavier duty than stock.

 

[Lumpy Grits]

That's what I use. It's called the C/F II, IIRC.
LG

 

[Petescj]

I was talking about this:

https://www.google.com/aclk?sa=l&ai...MID4KHcptBdcQwzwIHQ&ei=a9p7V4_wHczA-AHK25W4DQ

 

[Lumpy Grits]

That is pretty much what mine looks like, that I built.
Sure made for very smooth clutch pedal movement.
LG

 

[Oldguyinajeep]

The throttle down is the one I had my eye on. Like the design a lot. Those engine mounts do, indeed, look bomb-proof!

You mentioned you also had a 1" body lift. Did you alter your bell crank mount on the body side?

 

[Oldguyinajeep]

Yes. I have that exact kit.

 

[Lumpy Grits]

As strange as it sounds-After all the mods-It was level........
In it's OEM configuration, the body side was lower.
I used the MORE 1" alum spacers, for the body lift.
LG

 

[Petescj]

Look at a MORE Jeep engine mount and then the OEM style. Much less movement and far tougher/lasting design.
https://www.mountainoffroad.com/jee...motor-mount-kit-pre-99-cj-with-amc-6-cyl.html

Do you have the torque arm mount on your tranny mount set-up?

Here's the skid-plate I use. It's one 'tuff' SOB!
Throttle Down Kustoms TUBE SKID - Throttle Down Kustoms Custom Skid plate for 76-79 Jeep CJ - Quadratec

LG

You guys really do like to spend other people's money.