How long does a clutch last and how to check it?

[AwesomeJ10]

I recently lost (and have now replaced) the clutch master cylinder on the Honcho. Was out snow bashing when the clutch master cylinder started giving problems and ended up slipping the clutch pretty bad. Bad enough that I smelled it on 4 or 5 occasions. Replaced the master cylinder and now it seems fine.

Specs are; AMC 360/NV4500/Atlas 4spd/tons with 5:38's and 42's. I think the whole assembly has about 30-40k miles on it, but that is a only a wild ass guess as I have no odometer. The truck is only used for 'wheeling and has served as tow rig for about 3k miles (4000lbs camper) and did the UA (4k miles), went to the dunes about 20 times, over 100 local 'wheeling trips, Moab, Cruces, etc. (not a bad resume )

We are planning to drive it to Moab in 2 months, followed by the Walden dunes (towing) and then Ouray.

It has a 80's CJ7 6 cylinder clutch and matching master/slave on the stock AMC 360 flywheel.

So how long does a clutch last? Generally when 'wheeled hard? Is there a way I can test the clutch disc without pulling the tranny?

[ScottsMojo]

Is there an inspection cover which you can remove and measure the disc thickness? As with all wear items, there is a minimum safe dimension that needs to be measured to determine how much life might be left in it.

[Stuka]

When you go to drive it now, and you start to slip it, does it chatter at all? Typically a burned clutch will glaze and can cause clutch chatter.

Another test is to put it into a higher gear, like 4th, and let it out and see if it will stall the engine, or if it starts to just slip.

[AwesomeJ10]

When you go to drive it now, and you start to slip it, does it chatter at all? Typically a burned clutch will glaze and can cause clutch chatter.

Another test is to put it into a higher gear, like 4th, and let it out and see if it will stall the engine, or if it starts to just slip.

What exactly do you mean by 'chatter'?

After a full day of 'wheeling, it seems to 'bounce' when taking off from a stop light. It's almost like the traction bar is broken... (but it's not) It's pretty bad when I get back into town and have a few stop lights to go through. Never does this when cold. I suppose this is what you mean by chatter? I typically take off in 2nd gear, but when it does this, I'll use 1st to reduce the 'bounce'.

I just fixed it tonight and took it to the carwash down the street. Clutch feels good and doesn't seem to slip. Exactly as before. I'll try the 4th/5th gear thing and report back....

[Stuka]

That jerking is a form of clutch chatter. Its the clutch grabbing, releasing, grabbing, releasing. This is a typical side effect of having the clutch get too hot causing it to glaze.

My J10 actually does this and its annoying. Its from years of driving with 2.72 gears in the mountains. I have had had 4.56's for a while, but the damage was done back then. I am just going to live with it until I replace the engine and do it all at once.

Still tossing the idea around of putting in an NV3500 or NSG370 from a TJ at the same time. An overdrive would be so nice.

[jaber]

Just did a Dodge clutch and we had the flywheel turned to clean it up and the hardened spots from the heat cycles made it unusable. If theres heat discoloration on the flywheel, I'd replace it.

[csuengr]

Yous gots clutch chatter. The only way to get rid of it is a new clutch and surface the flywheel. Other than if it's slipping, or visual inspection, it's hard to tell when a clutch needs replaced. My dads truck has 110k on it and the clutch is still good. My Saturn got a new clutch a ~190k. Sounds like you have other issues, so If you are pulling the tranny, might as well fix the clutch. Funny how those NV4500's always need rebuilt.

[lil jeep mec]

clutches can last a long time! i have a friend that has a 93 dodge cummins that has 320,000 miles and the clutch only slips every once in a while, he can still two 8,000lbs behind it without the clutch slipping

[AwesomeJ10]

Update.

Replaced the harmonic balancer and was able to turn the motor over via the crankshaft nut while the tranny/case was in gear. I could see the flywheel turning while the driveshaft was stationary.

That's certainly not normal, is it?

BTW the truck still drives fine and yes, it will kill the engine if I even think about taking off in anything other than first or second.

[Stuka]

Hmm, that is strange. The only thing I can think of is that it was not fully in gear. With it otherwise being fine to drive and such, thats the only thing that makes sense?

[AwesomeJ10]

Believe me, the NV4500 was in gear. So was the Atlas 4 speed.

[Stuka]

Was the atlas previously in neutral by chance? Not sure how its shifter works, but if its not a positive engagement, it makes take a lot of spinning to get the teeth to line up before it will go into gear.

Try doing it again?

[AwesomeJ10]

No man. The Atlas was in rear hi (and had been there for a while) and the NV4500 was in second gear (the one I usually use to take off from a dead stop as first is too low). I turned the motor over SEVERAL times via a 1/2" standard craftsman ratchet while sucking the harmonic balancer into place. Every stroke of the wrench would turn the motor while gradually threading the bolt into the end of the crankshaft.

Maybe I'm pretty freaking strong? I dunno.

It worries me though. With my luck, we'll be down in the bottom of Pritchett canyon when both the clutch and the main bearings decide to let go. I dunno how on earth someone could pull me out of the exit of that trail. It would be bad.

[AwesomeJ10]

We took the Honcho out for a late night snow bashing run last night. The snow was deep and we fell off the road and had to winch a few times.

Lots of full throttle action.

Clutch worked great and I never smelled it.

Strange.