Jeep Enthusiast Forums banner

Clutch help

2K views 32 replies 10 participants last post by  Theman1945 
#1 ·
So this is regarding the sealed master/slave clutch cylinder. I changed out the system because I was having issues being able to shift into gear when stopped. I screwed that up and didn't get the slave cylinder rod on the clutch fork and emptied all the fluid onto the floor. I refilled the system and bled it by pushing the slave cylinder in manually until bubbles stopped coming out of the master cylinder. Everything worked great for about 100 miles. No issues getting into any gear, smooth shifting, and a nice firm clutch.

Today I was driving around and the clutch got sticky and was slow to come up, then it just went to the floor with no resistance for a couple pumps, and then came back to a relatively firm clutch that worked well getting me home but had a slight grind going into reverse in my driveway. Drove it a little while later and while sitting at a stop sign with clutch fully depressed and the jeep in 1st, the clutch just decided to engage and I just took off...thankfully there was no traffic. This happened several more times before I could get back home but I was much more careful about putting the jeep in gear until everything was clear. I've tried to rebleed the system but nothing is making a difference and I can't really even shift into gear stopped on level ground now.

Any advice or help on what the heck is going on?
 
See less See more
#2 ·
Just get a new pre-bled M/S cylinders. You might have did some damage by initially installing it wrong. But the fact is the junk we buy these days is a trap-shoot. Maybe try a different brand. Lucky for you it is easy to install.

I do not believe you can repair it. (the cylinders I mean)
 
#33 ·
My last prebled unit slave cylinder went bad in under a year; out $100. Consequently, I recently found out that Oreily's sells the master and metal external slaves individually, both of which come with a lifetime warranty, so you can just exchange it if it goes bad. Together they cost around the same as the prebled units. So if you have the line that goes between the two, I'd highly recommend just picking up the individual cylinders now. Bled and replaced my slave cylinder in under 30 minutes.

Not sure if anyones done it, but I'm sure with a little modifications you can use the metal XJ master cylinder too.

Slave Cylinder
YJ Master Cylinder
XJ Master Cylinder
 
#3 ·
I've got the same issue with all new parts in my '93 4.0L, including a Centerforce II clutch which was a waste of money. Half the time the clutch feels/performs as it should and half the time it feels dead, flat, grinds gears, etc, with no drop in fluid level in the reservoir. I'm assuming that the slave is leaking by internally, but not leaking into the bellhousing, but I don't know this for a fact.
What I do know is that I've had enough. This is the third slave cyl/release bearing I've installed in the last few thousand miles. After the first of the year it's all coming out and I'm converting to an external slave system with a Luk clutch. Hopefully that fixes the clutch issue once and for all.
 
#5 ·
This is why filling out your profile is important. I'm assuming Waternut is talking about an external slave and KCYJ is talking about an internal.


I'm not sure how you can get the slave on the trans without the plunger hitting the arm, I'd be curious to see if something inside (ie one of the retention springs) has come loose.
 
#6 ·
This is why filling out your profile is important. I'm assuming Waternut is talking about an external slave and KCYJ is talking about an internal.
Not to be a jerk but I tried to put all the pertinent information in the original post. I'm also not sure how to fill out my profile with half 88 body and frame, half 95. 95 engine, ECU, and clutch hydraulics with modifications to the firewall to fit it properly. Brake system from an 88. Partial Rough Country lift, partial custom, and electronics that resemble a track car more than a consumer vehicle... Anything I put in my profile will be misleading.

I'm not sure how you can get the slave on the trans without the plunger hitting the arm, I'd be curious to see if something inside (ie one of the retention springs) has come loose.
That was kind of my thought as well which is why it got screwed up. The clutch fork is sagging down slightly below center and I installed the slave cylinder angled slightly upwards because it's easier to snug up the lower bolt first so it missed. If something sounds off about that, please let me know.
 
#7 ·
I get the profile being off a bit, no worries, I wasn't trying to be a jerk either. It's just that 3 posts in the topic already changed to a different animal.


I'm thinking if the arm is sagging, something's not right inside the bell housing.
 
#8 ·
I get the profile being off a bit, no worries, I wasn't trying to be a jerk either. It's just that 3 posts in the topic already changed to a different animal.

I'm thinking if the arm is sagging, something's not right inside the bell housing.
Thanks. I'll run a borescope up in there tomorrow when I get the new cylinders and see if anything bad is going on.
 
#9 ·
So a borescope didn't show much and the new clutch master cylinder/slave cylinder didn't really make a difference either. I don't think the clutch is going out because it's very responsive with upshifts like it should be and can bark 33" tires on pavement if I get too aggressive at a stop sign.

The only other things I can think of is to try a 4th clutch master/slave cylinder, change out the tranny fluid, or drop the transmission and see what's going on.

Just for the record, this is why I missed the clutch fork. It does wiggle around inside but with a little pressure from the slave cylinder it centers up and doesn't budge.

I'm really close to just rolling with it the way it is and slam it into reverse and 1st when stopped so it doesn't grind....provided this new master/slave cylinder doesn't randomly hit the floor.
 

Attachments

#10 ·
...Today I was driving around and the clutch got sticky and was slow to come up, then it just went to the floor with no resistance for a couple pumps, and then came back to a relatively firm clutch that worked well getting me home but had a slight grind going into reverse in my driveway. Drove it a little while later and while sitting at a stop sign with clutch fully depressed and the jeep in 1st, the clutch just decided to engage and I just took off...thankfully there was no traffic....
...the new clutch master cylinder/slave cylinder didn't really make a difference either...
I'm not sure why you say the new cylinders did not make a difference. It is not jumping into the intersection anymore, right? If you start the engine while in 1st gear, it doesn't lurch forward, right? When you start the engine while in gear, do you feel it trying to move forward at all?

If those things are good, then the clutch is disengaging as it should. Grinding while shifting may be a transmission problem.

There can be other issues that cause the transmission input shaft to still be turning while the clutch is supposed to be disengaged. Such as a warped friction disk, bent fingers on the clutch cover, bad/dry pilot bearing, bad/dry release bearing. Any of those will require dropping the tranny to diagnose.

A couple of other things to ponder...you left the plastic tip and straps connected on your new slave cylinder, correct? The straps are supposed to break after installation the first time you press the clutch. The misalignment of the fork in the opening looks about normal to me, so I don't think that means anything.
 
#12 ·
Well the reason I say it didn't make a difference was because the last time I changed the clutch hydraulics, the grinding and all other issues with shifting completely disappeared for 100 miles until everything bad started happening. If I start to shift into 1st in my garage, the jeep will start to move on the synchros with the clutch pushed in and if I jack up the rear, the wheels will continue to spin with the clutch fully depressed. The vehicle doesn't lurch forward when I start it but if you pay close attention, it will budge a little.

Also, the clutch randomly dumping at an intersection was a random thing. It only happened occasionally so just because it's not happening doesn't mean the problem has gone away.

I do think that something is still wrong that may or may not be related to the clutch hydraulics so I foresee a transmission drop in my near future.

I personally think it looks way too low, but I'm not an expert by any means, as I only recently did this swap myself.

I've never really understood the point of the plastic retainers, (other than not having to compress the cylinder to install) as the instructions that came with my slave said to take the strap off and manually manipulate the cylinder to bleed it.
Yeah the plastic retainer is a bit irrelevant and mostly just a convenience in my mind. It's not hard to install without it at all.
 
#11 ·
I personally think it looks way too low, but I'm not an expert by any means, as I only recently did this swap myself.

I've never really understood the point of the plastic retainers, (other than not having to compress the cylinder to install) as the instructions that came with my slave said to take the strap off and manually manipulate the cylinder to bleed it.
 
#13 ·
It's so hard to tell these days. The "New" Jeep parts don't always function correctly out of the box.

Although it is usually the NOS internal slave cylinders that have been failing on us right out of the box. So much so that some people are buying the entire Luk clutch kit because the slave seems to usually work.

I'm not sure what the failure rate is on the sealed master/slave combos.
 
#15 ·
Well a bit of an update on this... I'll be dropping the transmission sooner rather than later. Driving home today and the clutch just quit completely. Had to get towed by a friend to at least a grocery store so I can get a trailer tomorrow. Something internal is bound up because the clutch is rock solid once it engages the clutch fork to the point that I blew the line off the slave cylinder. Originally thought it was another bad clutch hydraulic system but the old ones were the same now. The clutch fork wobbles around inside the bell housing a few inches in all directions.

I'm guessing the throwout bearing, spring, or something just broke and has jammed everything up.
 
#18 ·
I found the problem. Looks like the throwout bearing just grenaded. The transmission is back in and everything feels super smooth. The clutch is actually softer yet does more with no grinding.

I didn't get a chance to test it though because the shifter just would not lock back into position. I fought with it for close to an hour and gave up so I could get everything else in. I can't see anything causing an issue either but I'll tackle it tomorrow with the shift boot removed (ugh).
 

Attachments

#22 ·
I found the problem. Looks like the throwout bearing just grenaded. The transmission is back in and everything feels super smooth. The clutch is actually softer yet does more with no grinding.

I didn't get a chance to test it though because the shifter just would not lock back into position. I fought with it for close to an hour and gave up so I could get everything else in. I can't see anything causing an issue either but I'll tackle it tomorrow with the shift boot removed (ugh).




While I don't have near the experience with Jeeps and clutches many of you do, I have to ask if that clutch arm (or whatever its called) is supposed to be in that position?? Then looking at the second picture I don't see the correct bearing retainer supporting the throwout bearing.... If I'm just missing something in plain sigh, won't be the first time but this is not all a factory setup is it???

Would still having an older, internal slave, style bearing retainer explain any of this???
 
  • Like
Reactions: Jeepsr4me
#19 ·
Oh yeah, that'll definitely cause problems.


The shifter not locking in? You mean the lock ring itself? I've found it easiest to use two flat blade screwdrivers, one on each side, to push it down and turn. Seems to have better friction than my fingers.
 
#21 ·
I had the same problem last time I pulled the trans. My neighbor came by to see what I was doing. Probably because of all the cussing going on in my garage. He said, "Oh that's easy". In 20 seconds he had it locked in, using his fingers. I mark it up to him being 25 years younger than me.
 
#23 ·
flcracker said:
While I don't have near the experience with Jeeps and clutches many of you do, I have to ask if that clutch arm (or whatever its called) is supposed to be in that position?? Then looking at the second picture I don't see the correct bearing retainer supporting the throwout bearing.... If I'm just missing something in plain sigh, won't be the first time but this is not all a factory setup is it??? Would still having an older, internal slave, style bearing retainer explain any of this???
I think you nailed it. The bearing retainer should have a tube extending out of it that goes around the shaft. The lever and throw out bearing would be supported by that tube.
 
#26 ·
Aww that sucks! Sounds like I'm going to have to pull the tranny again in the near future. It won't be immediately though... especially since I don't drive this very often. That also explains the sagging clutch fork. I am super glad you guys noticed that though.

Since that part is over $100 and requires a ton of work, this may be one of those things that get fixed with a transmission swap or engine/transmission swap.....or get blown off until something breaks at which point I'll replace the clutch and everything else in there.
 
#27 ·
Suggestion, before you buy anything, make sure that tranny is an AX5. Someone obviously has done a swap, and swapping an AX15 in place of an AX5 is a common upgrade. From the photos so far I cannot tell which you have.
 
#30 ·
Very good question. I tried searching that a week or so ago and came up with only a slight notion that it was probably an AX5 based on looks since all the length measurements I took were perfectly in between the two...lol.

Having taken a picture of the flywheel and input shaft though, I can say it's an AX5 with the 14 spline shaft.
 
#32 ·
Well figured I'd come back and give the final (hopefully) results.

After about 100 miles or so, the new throwout bearing started getting crunched. No clue how the old one lasted as long as it did but this one didn't last long at all. So I managed to find the correct bearing retainer on Amazon for $70 with the seal. After mounting the transmission twice, because I'm an idiot and didn't mount the new throwout bearing and clutch fork the first time, everything works perfectly. Clutch is consistent and there is no more grinding noises. Thanks for all the help.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top