May need a new clutch. Recommendations?

[brucecooner]

I took my MJ out for a pleasure cruise yesterday evening, and when I was close to being home the clutch decided it no longer wanted to disengage. The rest of my drive involved some intense negotiation with the pedal and shifter.

 

I checked the fluid in what I think is the master cylinder this evening, and it shows to be plenty full.

 

 

This did make me suspicious that the fluid coming out of the bell housing was actually clutch fluid but upon closer inspection nope, it feels like oil. So the hunt for that leak will continue...

 

It failed to disengage a couple of times on last week's drive too, but the condition wasn't persistent.  Both times it's happened, it was only after a couple dozen miles. It could be something you have to drive a while to cause, but I can't say that for sure because it's a new behavior.

 

If anyone has other suspects to interrogate that might point to the issue, I'd be interested to hear about 'em.

I'm hoping this isn't a transmission issue.

 

As far as I know this is the original clutch, so at 190K it seems normal it could decide its clutching days are done.

 

I don't have the space, skill, nor time to go after replacing a clutch, but thanks to a fellow local MJ owner I've got a bead on a shop that specializes in AMC products.

I called them up and talked to them a couple of weeks ago, feeling them out on a few potential things that I thought might come up on mine. The owner seemed nice and knowledgeable. A few things I mentioned he said were easy enough for me to do without even bringing it in.

but I brought up a clutch (not knowing mine was about to lay down on me) and he recommended a Center Force dual friction job. 

Upon research, this just sounds like a performance oriented clutch meant for competition.

That shop works on Jeeps, but they build a lot of big block street bruisers, so maybe that's why a comp clutch is his preference.

I surely don't need anything competition rated though. I'd actually be afraid of sending too much power too quickly through the old Peugot gearbox.

 

What I'm most interested in is not performance but durability and reliability, boring stuff like that.

In the other clutch thread Luk was spoken of very highly.

Is that the goto brand for most guys?  They last pretty well?

I hope to be doing some light offroading with this thing eventually (nothing intense, just some mildly rocky stuff here in AZ).

Is there a style of clutch more suited to offroad use? 

 

[87MJTIM]

LUK is my go to clutch kit 

[cruiser54]

It's likely a hydraulic issue. Like fluid bypassing in the clutch master cylinder. 

[JMO413]

10 hours ago, 87MJTIM said:

LUK is my go to clutch kit 

[brucecooner]

16 hours ago, cruiser54 said:

It's likely a hydraulic issue. Like fluid bypassing in the clutch master cylinder. 

 

It does seem to grip okay once it's going, it's the disengaging that ain't happy.

Is there a way to check if the fluid is going where it's supposed to?

 

 

But it looks Luk is the preferred brand around here. 

I see the "heavy duty" jobs with increased grip and all, and I do plan on climbing a few hills.

But at the same time I don't want to shock the tranny.

 

 

 

[cruiser54]

Try this.

Pump the clutch pedal about 40 times and then walk away for 10 minutes. 

Look up inside the cab where the clutch pedal attaches. Is fluid leaking into the cab above the fuse box?

See if some fluid came out between the engine and trans. 

[brucecooner]

 

I gave it a bunch of pumps then waited...

 

The cylinder on the pedal looks pretty clean.

A little fluid on the ram, but nothing dripping from the cylinder inside.

 

 

 

I crawled around under it with a flashlight, and didn't see any fluid on the lines that go into or out of the front of the transmission.

No fluid between engine and transmission.  The dust cover plate is still dry.

There is that leak behind the dust cover plate, but that is oil and not brake fluid.

 

I'm pretty okay with a new clutch at 190K.  I like the idea of knowing its exact age.

 

As always, thanks for the help.

 

 

[cruiser54]

That "ram" should be dry. 

[brucecooner]

I'll pump it again when I'm back in the cab and check the rammy part for fluid. I was noticing you could see fluid in the opening of the seal at the end, some is definitely leaking out here.

 

I wonder if that's a sign of bad seals in the, whatever the pedal-pumpy thing is called, which might mean it's not pushing a sufficient amount of fluid to the slave(?) cylinder.

I bet that thing is a complete pain to access and change, too.

[cruiser54]

Clutch master cylinder is connected to the clutch pedal via the rod you see inside the cab. 

[brucecooner]

For some reason I perceived that the master cylinder was much higher than the pedal on the firewall.

I was confused because under the hood I'm looking at the reservoir, but the cylinder must be below the reservoir, and the pedal is attached to the cylinder.

I learn something every day.

 

I wonder if leaky seals in the cylinder might be the cause of the lack of disengagement.

If too much fluid bypasses the pushy part, maybe the clutch doesn't get the message.

 

Can the master cylinder be tested somehow?

I sense a pressure test somewhere might be the answer.

[cruiser54]

After all that pumping, you still have the same symptoms? Do you ever get a firm pedal any more?

Does the fluid level in the clutch master cylinder go down?

Do you see brake fluid on the rod where it goes into the clutch master?

Absolutely sure the fluid coming out between engine and trans is only oil? 

 

[brucecooner]

On 5/31/2022 at 4:57 AM, cruiser54 said:

After all that pumping, you still have the same symptoms? Do you ever get a firm pedal any more?

Does the fluid level in the clutch master cylinder go down?

Do you see brake fluid on the rod where it goes into the clutch master?

Absolutely sure the fluid coming out between engine and trans is only oil? 

 

Even when the clutch is failing to disengage the pedal maintains about the same stiffness.

 

I raised the hood and watched the reservoir as I worked the pedal, and the level changed, but barely.

Set my phone up and got a video of it too.

 

 

Looking for fluid on the pump rod, I wiped a paper towel on the rod and, rather than being covered with clear slick fluid it has this black...gunk on it.

 

 

I might be looking at the remains of a seal I guess. Or maybe it's just supposed to be greasy.

 

The fluid coming out of the bell housing is too viscous to be brake fluid, unfortunately.

 

The cylinder says "NABCO Japan" on the side and looks fairly new. It doesn't look original to me.

That said, on a truck this age it could be a replacement but still be a couple of decades old.

 

I'm suspicious of that black ring in the reservoir at the fluid max level. 

Might be a sign of dead seals, but could just be rub off from the lid.

The fluid is a kind of orangey yellow too, nowhere near clear.

 

 

The clutch has never been super firm, but isn't spongey either.

Only getting in this a couple of months ago, I don't know what the baseline firmness is supposed to be though.

 

 

Automobiles are an endless source of mystery.