Clutch problem

[landozion]

Got an interesting clutch problem. This is on a 91 Justy, some days it works fine, other days I can't shift gears at all, it just grinds. If the engine is off I can shift fine, but once I start it no luck. Wait a day or two, and it works again. What could cause this? I am thinking a release or throwout bearing that is not sliding like its supposed to. Anyone every encountered something like this before? I dont want to put a lot of money into this car, but I dont want to give up on 40 mpg either! Thanks for any ideas.

[nipper]

Have you ever tried shifting the car after it has shut off for an hour?

 

 

nipper

[landozion]

Yes, I have. Sometimes its fine after an hour, other times it still wont shift. Obviously its an intermitant problem (the worst to try and diagnose), hoping someone else out there has seen this before.

[Adnan]

Hi,

 

Curious problem. If you go through the system step by step, there aren't too many parts involved:

 

Master and slave cylinder - the master leaks so much when hot that it can't actuate the slave. Conversely, slave leaks so much when hot that it doesn't actuate the fork. This should be easy to eliminate by looking at the slave while someone presses the clutch pedal.

 

Fork - can't imagine how this can contribute to the problem. In any case, the above visual inspection will tell you if it's moving properly.

 

Throwout bearing - bearing gets stuck on the shaft and won't budge even if the clutch pedal is pushed. Unless the hydraulics are leaking, this is extremely unlikely.

 

Clutch disc - the disc gets stuck to the flywheel when hot. Since there is no active preload on the disc pushing it off the flywheel, it may not be moving off, causing grinding. Depending on the car, there may be an inspection port that lets you see the disc. Again, a visual check will tell you.

 

Pilot bearing - I don't know if the Justy has a bushing or a real bearing. When hot, the pilot could be grabbing the input shaft so even if the disc is free, the shaft is still turning with the flywheel.

 

If I were a betting man, I'd say it's more likely to be one of the last two.

 

Regards,

Adnan

[cookie]

The old ones I have worked on were cable. It does really sound like a hydraulic clutch problem though.

[nipper]

This is sounding more and more like a bad hydraulic clutch (if the car doesnt have one i'ld go with the clutch).

 

Try this, from a dead stop put the car in third gear and try to take off. The car should protest a lot, and maybe even stall. If the clutch is bad, the clutch will slip.

 

What I think is happening, is that when the car is cold, all the tolerances inside the cylinders are nice and tight. As the car warms up, fluids thin out, parts expand. Fluid starts bypassing the internals, and you cant shift. If it was me, I would replace both the master and the slave cylinder.

 

I had a 79 civic that would do this on occasion, but it would require heavy bumper to bumper stop and go traffic. On occasion some clutchs wil do this as they cant dissipate the heat (summer, ac on, moving 5 feet at a time for many miles). Once the clutch cooled of (in about 5 minutes) the issue went away.

 

nipper

[landozion]

It is a cable actuated clutch, thanks for all the responses, Adnan gives some good troubleshooting advice to try and narrow it down, as soon as it stops raining, I will see what I can figure out. Thanks all again, and keep em coming!

[nipper]

Cable clutch, sure, make it tough. Examine the clutch cabe carefully.

 

http://clutchwizard.com/diagnosis.htm

 

 

see if that helps.

 

nipper

[cookie]

with mechanical linkage it was only a few different things. The easy one is wear on components that keeps the cable from moving far enough to disengage. The best happens when you remove a bit of clearance from the clutch and it is just enough to get you by for a while. The worst is a clutch disc coming apart, or a disc so worn that the pressure plate over centers. Most likely you will need a new clutch to fix it.

[nipper]

Just out of curiostiy, whats the milage on this puppy, and is it the original clutch?

 

 

nipper

[landozion]

Somewhere around 240,000 miles, but new clutch 4 years ago, its been a good commuter car, and with the price of gas, hate to junk it now. I am getting quotes of 5-700$ for a clutch job, way more than the car is worth. (last one was done by a friend who is a mechanic who has since moved out of the area). Anyone know a good suby mechanic in Ogden, Utah?

[nipper]

DOnt go by what the car is worth, go by what the car is worth to you. Also what would you replace it with, and how much would it cost to buy a rpelacement, then all the regitration fees etc etc. Unless the body was shot to hell, i would put a clutch in it .

 

 

nipper

[landozion]

Just to update this post, got it torn down, and its a bent fork, or at least thats what the mechanic says, we will see.......