MAYDAY!- Clutch Pedal Flopping, No Disengage

[USAFSS-ColdWarrior]

Driving home on Saturday, 7/24/2010, with just one stop sign to go, I was shifting from 3rd to 4th and the clutch pedal "went floppy" and wouldn't disengage the clutch/drivetrain.

When I say, "went floppy", I mean that the pedal depression effort dropped to near nothing, although it does still return to the regular postition on its own. There's virtually no resistance nor response to downward effort.

I was able to no-clutch shift to the front of the house and get her parked by the curb, snatching Neutral as I rolled to a stop. I did idle-in-1st through the last STOP sign two blocks from the house, but thankfully, there were no other cars there. I was prepared to kill the engine and restart in gear if I had to.

I have not yet had a chance to crawl on or under her to see if there's a linkage problem or if it might be something inside the bell housing.

The Fire Department that I got her from back in March had advised that the clutch slipped sometimes, and that some of their drivers liked to ride the clutch instead of using low gears and throttle control while fighting pastureland brush fires. They had suggested that she might need a clutch soon. HOWEVER, the symptoms they described - slipping- had not been a problem for me.

Anyone out there with a similar experience?

Am I looking at a linkage "disconnect"?
Or possibly a throw-out bearing or pressure plate problem?

I'll know more when I can look her over, but at this point any input would be appreciated. Will update as the diagnosis is determined.

I did backtrack my route in the mini-van almost immediately after the failure and found NO PARTS or HARDWARE laying on the pavement along the way. (Thought this was a good sign.)

Thanks for any help/input.

Looks like it's time to GO MECHANICKING

 

[gimpyrobb]

Yup, could be alot of stuff. I would look for anything disconnected in the linkage first, then drop it to see if its the pressure plate, throw out bearing or something else. SOunds like you have some heavy work in front of you.

 

[doghead]

If I was a betting man, I'd bet your pressure plate gave out.

Look for something obvious(external), then drop your transmission and do a clutch job and replace your rear main seal while your in there.

 

[USAFSS-ColdWarrior]

Yup, could be alot of stuff. I would look for anything disconnected in the linkage first, then drop it to see if its the pressure plate, throw out bearing or something else. SOunds like you have some heavy work in front of you.

It's not a complete suprise, that's to the Fire Chief's forewarning of possible clutch needs.
We bought it with the understanding that she's 42 years old (19 years since total rebuild by the Army).
Considering our REALLY LOW purchase price, this is just a little bump in the road. It'll be great experience too, no matter what magnitude of repair it needs.

 

[USAFSS-ColdWarrior]

If I was a betting man, I'd bet your pressure plate gave out.

Look for something obvious(external), then drop your transmission and do a clutch job and replace your rear main seal while your in there.

Thanks for betting on the "Most Optimistic Option" there, DH

Do I hear any wagers on something simpler/cheaper

I know I have a small oil lead in the back of the engine anyway, and if the tranny's to be dropped, will do the main seal and anything else accessible at that point as well. The oil drips from the bottom of the bell housing, so I'm suspecting it's the rear main seal.

 

[clinto]

That sounds like a pressure plate failure.

You need to get under it and inspect the clutch linkage and while someone actuates the clutch pedal, watch for failure.

I'll bet you end up doing a clutch. Goes without saying you ought to do a rear main while you're in there.

 

[Bob H]

Throw out bearing or linkage.
I suppose it could be the pressure plate fingers broke off, never seen that before tho....

 

[M813rc]

My 813 did that one day while it was idling right after I parked it and was letting it cool down. The pin that holds the clutch pedal to the actuating rod (under the cab) had fallen out, I found it just sitting on the frame rail. If it had happened a couple of minutes earlier it would have been a moment for sure! Actually, it was anyway...

Cheers

 

[gimpyrobb]

Kip just got a deuce with the same issue. Let us know what you find!

 

[RAYZER]

pull the rectangular plate on the bottom of the bellhousing and take a look.

 

[Crazyguyla]

sounds like you might have the weaker 4 finger pressure plate. I read somewhere that the 4 finger pressure plate was prone to failure. The stress of the FD riding the clutch probably contrubuted to the failure.

 

[USAFSS-ColdWarrior]

Great input, Guys. Thanks.
Sorry I've not yet gotten under her to take any pics or eyeball the situation. As soon as pics are available, I'll be posting them up.

BTW - About how much does the tranny weigh??? The only other one that I've ever dropped was in a '64 Chevy Impala SS, and that laid nicely on my chest.... Don't suppose that would be recommended this time, huh?

 

[gimpyrobb]

NO! Your looking at about 225lbs.

 

[USAFSS-ColdWarrior]

NO! Your looking at about 225lbs.

Thanks Gimpyrobb.... I was guessing about 300 +/-25. Still much too heavy for the ol' chest to carry, but I surely wasn't even considering that as a plan.

 

[1stSarge]

Well, for a more optimistic approach, (however unlikely) I had a ‘69 charger where the linkage slipped “through” the yoke. Exactly the same symptoms. Fixed it with a couple of grade 8 washers. I don’t know what this looks like on a duece, or if its possible. --maybe I'm just trying to make you feel better.

 

[USAFSS-ColdWarrior]

Well, for a more optimistic approach, (however unlikely) I had a ‘69 charger where the linkage slipped “through” the yoke. Exactly the same symptoms. Fixed it with a couple of grade 8 washers. I don’t know what this looks like on a duece, or if its possible. --maybe I'm just trying to make you feel better.

Exactly the sort of thinking that causes my optimism....

On a 1990 Ford Probe, had the clutch pedal drop to the floor and stay there. Both Master and Slave Cylinders and the Reservoir proved faultless. Turns out that the yoke/throw-out were "sticking". I slipped the tube on a WD-40 spraycan into the clutch chamber via the rubber seal at the yoke entry point. I unloaded about 1/4 can of WD-40 and freed it up. Didn't swing a single wrench to fix that problem. The HOT/DRY west Texas environment does odd things to mechanical parts.... it's usually not rust, but DUST that makes sliding things stick around here.

While I thought it was time to tear down that drivetrain, it turned our to be a much simpler fix.

I'm hoping beyond logic to find a similarly simple outcome.... But then again, I'm an "infernal optimist"...

 

[LanceRobson]

As written above, check the pins/bolts in the linkage first. If all you seem to be feeling is the pedal return spring you might get lucky.

Then pull the inspection plate off the bottom of the tranny. Check the fingers of the pressure plate. If any of them are flopping around as opposed to being under spring pressure they are broken. Rare, but it happens. In fact PsycoBob dealt with one this month. We had a pressure plate with two broken fingers. There was still a fair amount of spring tension to overcome though so if you are feeling very little I'd bet on the linkage.

Check the oil that has leaked into and around the clutch and flywheel areas. You should be able to tell the difference between engine oil and transmission oil by smell. The supposed rear main leak could be coming from the transmission input shaft.

Engine oil is a lot less likely to get on the clutch side than transmission oil is. If the clutch is contaminated I'd look at the tranny first. One of our trucks got the clutch comtaminated due to water build up in the tranny. I had changed all the fluids and then the truck sat outside for a year. After the leak I drained the tranny and there was a lot of water in the bottom. That'll teach me to not put all the trucks in the shop.....

There are lots of threads about doing the rear main seal and to do that you'll have the tranny and flywheel out so it's worth doing it right.

If you decide to drop the tranny and inspect everything shoot me a PM with a phone number. We've done two in the last month and I'd be glad to talk to you about it.

Lance

 

[swbradley1]

BTW - About how much does the tranny weigh??? The only other one that I've ever dropped was in a '64 Chevy Impala SS, and that laid nicely on my chest.... Don't suppose that would be recommended this time, huh?

After helping Stretch at Haspin change his rear main seal and watching the tranny fall off the chain hoist once, the last place I would want to be is under it even if it wasn't falling.

BTW I did 3 engine and 4 transmission changes in my 67 Chevelle SS in the 4 weeks before boot camp. Those old 4-speeds were not that heavy back then (at least I remember it that way).

sw

 

[rlwm211]

I am betting you had the pin that connects the pedal to the linkage from the bell housing fall out.

I replaced the indexed pin on my deuce with a 1/2 inch bolt and nylon stop nut. I saw that as a problem waiting to happen.

RL

 

[USAFSS-ColdWarrior]

The problem is OBVIOUS ! ! !

Well, I finally had the time to crawl under the Deuce (and even brought the camera on the first "dive").

IMMEDIATELY, the problem with causing the floppy clutch pedal was visually OBVIOUS (see pics below)

I guess I'm now looking for a replacement ROD. Does anyone out there have one laying around or hanging under a donor truck