Clutch or Master Cylinder/Slave?

EvilRbt

EvilRbt

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Aug 16, 2022
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Los Angeles
When I got my 93 YJ a couple of years back, shifted gears real smooth. Lately (last month or so) I've noticed it starting to feel a little notchy.

Figured if might be transmission fluid so replaced with Redline MT90 and noticed very *slight* improvement.

Topped up brake fluid in master cylinder too.

Still feels a bit notchy, even going from 1st to 2nd it's like I can feel a notch on the left side. At stops, I usually shift to 2nd before 1st. As for reverse, really gotta pause at idle or it'll crunch.

Is this my clutch beginning to go out, start of bigger transmission/synchro problem, or might I just need to replace the clutch master cylinder and slave?

THANKS for any advice!!
 
Are you losing fluid? is the pedal spongy? is your Yj a 4 banger with the AX5 which are not particularly a durable trans and if you do the clutch slave/master remember the slave is inside the trans so you'd do the clutch/slave and master all at once.
 
Yeah, 4-banger.

Don't appear to be losing fluid. Pedal is not spongy. Feels like this has come on fairly suddenly (again over a month) and quickly worsening.

Coincidentally, my brake master cylinder went out last year and the speed of deterioration feels the same. My brake pedal was getting stiffer and after a month or so it was undriveable.

Not sure if that means it's my clutch master cylinder and my clutch just isn't disengaging properly...
 
try driving while you double clutching to see if it acts the same way. if so it may be a gear problem.
 
dieselearl said:
try driving while you double clutching to see if it acts the same way. if so it may be a gear problem.
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I'll try it out tomorrow. I just crawled under to look at the slave and find this... Not what I was expecting. Am I insane or isn't there supposed to be bolts and a plate to mount this to the transmission? It's just hanging there!


IMG_8602.jpeg
 
Reverse always crunches since there's no synchro for it. I always go into 2nd to stop any rotation then quickly into reverse. That usually does the trick. Try any gear other than 5th because there's a lock out which prevents you from going from 5th into reverse by mistake when driving.
 
Flyer58 said:
Reverse always crunches since there's no synchro for it. I always go into 2nd, to stop any rotation, then quickly into reverse. That usually does the trick. Try any gear other than 5th because there's a lock out which prevents you from going from 5th into reverse by mistake when driving.
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That is the bleeder for the slave and yes you can move it around. The line hanging off it is not stock as IIRC it had what looks like a brake cylinder bleed valve at the tip only.
 
Gilaguy23 said:
That is the bleeder for the slave and yes you can move it around. The line hanging off it is not stock as IIRC it had what looks like a brake cylinder bleed valve at the tip only.
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All the pics/videos I’ve found to learn how to do a clutch master cylinder install look like this… Why does mine just sit in an open hole in the bell housing?

J11616-img7.jpeg
 
One of the down sides of early YJ's, as well as many other vehicles, is the slave was installed inside the bell housing. Unless your was changed you wont see the slave, only that stub sticking out the hole in the B/H. The YJ was changed to external slave in 94 IIRC. There is a way to put your on the outside but IMO its not worth the hassle but thats just my opinion. The pic is the jewel inside the bell housing.
jeep slave.jpg
 
Aw man. So I’d have to drop the transmission to replace, and if I do that I may as well replace clutch? Not allowed to do repairs where I live so I’d have to go to a shop. Any ballpark on what I should look to pay?
 
Also check the transmission fluid level. It may be low or never changed at all. The synchros are made of a sacrificial metal that wears out long before the gears do and 2nd gear is often the first on to wear out. In several different vehicles, I've had to start the engine while in first gear and shift through the gear pattern just to get me home after the clutch quit working. If the synchros are all good and the RPM's are equal, the gears just falls into place. If the synchros are bad they will almost always grind when shifting.

This is what I found with 2nd gear.

1711302034785.png
 
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I just bought Redline and had it replaced. They only used 3 qrts and didn’t touched the 4th bottle but I’d read it takes 3.5 qrts. Can anyone confirm that? If so maybe I just need to add another 1/2 qrt
 
EvilRbt said:
I just bought Redline and had it replaced. They only used 3 qrts and didn’t touched the 4th bottle but I’d read it takes 3.5 qrts. Can anyone confirm that? If so maybe I just need to add another 1/2 qrt
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I missed that part about the redline fluid. IF you transmission is level it should take about 3.3 quarts. There's a bolt hole the fluid will come out when it's full. If your YJ has a lift kit or transmission drop kit that level will be close but I don't what to say about performance or fluid level change.
 
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