Strange clutch issue -- new post-er

[785sp]

Hello everyone. I've been reading this forum for a while. Since I'm an amateur, I've only posted my 2-cents on the Roadfly site. But now, I have an issue that keeps generating blank stares from those who should know. Maybe someone here has an idea.

The car is a 78 5sp, with the earliest version of various parts. I recently had to replace the bell-housing, on which the clutch-arm pivot had snapped off. Replacing that involved, of course, a new bushing for the clutch arm, flushing the clutch, and re-adjusting the double-disks. The slave-cylinder and master cylinders are intact with no leakage.

Since that repair, which has otherwise allowed good shifing in all gears including reverse, a strange problem has developed. The problem is getting progressively worse, and I'm getting progressively worried.

When in any gear, and particularly in second or third, if left in gear and if constant rpms are maintained, a looseness develops in the clutch pedal, with about 1 inch of play. Also, a strangle rattling noise begins from somewhere behind the stereo. The rattling noise does not sound like a clutch bearing, but rather like the sound loose linkage might make under vibration. The rattling noise can be "felt" if the left foot rests gently on the clutch pedal.

Stranger still, when I put the car up on a lift last weekend to flush the clutch again (this time with a proper vacuum machine) the looseness symptom went away completely while up on the lift, but returned as soon as the car was back on the ground. So, my guess is that the symptom has something to do with the weight of the car on the suspension, which then is causing the clutch linkage to flex somehow, which then is allowing extra play...?

I'm just guessing at this point, but those are the facts. Again, the usual suspects can be ruled out (air in the system, worn bushing, double-disk adjustment, leakage, etc.). Any advice is greatly appreciated.

Dave

[DanielDudley]

Check to see if the clutch arm is on the ball.

[Danglerb]

If your in Los Angeles, take it by and let Greg at Precision or Jeff DeVitos take a look. (Anaheim and City of Orange respectively)

OTOH this sort of thing can be shooting in the dark to sort out.

When you lift the car, is by the frame or wheels?

Constant speed, implies constant rpm, so anything that "wants" to vibrate near that frequency is going to vibrate. Sounds like you need a passenger that can snoop around listening for the source of the noise while you pay attention to driving and traffic.

I'm in the City of Orange, and a couple others on this forum are west of LA, tell us where you are more specifically and someone can help.

[rhjames]

please check out my replies on the previous clutch problem post as well....

even though your cylinders look good (mine did), they may be bad (they were), causing the clutch pedal to not return to it's full upright position.

yours does sound like a linkage issue, but check the cylinders just to be sure.

other things to consider:

did you get the clutch discs, pressure plate, throwout bearing, etc., properly aligned before tightening them to the flywheel? how about the torque tube connecting sleeve---is it tight? did you recheck this?

good luck---let us know what you found.

[928ram]

Sounds like the linkage, specifically the ball/socket being sloppy or fallen away during install.

How about the throw-our bearing; is it the proper one for that year? Somewhere in the life of my '79 someone had replaced the t-o bearing with a mid-year style which will fit in there but doesn't float on the arm as it should; this in turn shredded my forward disc. Thinking along those lines, undue pressure against the slave cylinder could cause the fluid to pump back toward the master, causing as sloppy pedal.

[785sp]

Thanks for the four replies.

The idea of the slave cylinder going out even without signs of fluid leakage is intriguing. Almost everything else on the car has failed after 30 years, so why not that!

Regarding the linkage possibly having slipped, the reason I replaced the bell housing in the first place was due to the ball-pivot having snapped off, so I know what it feels like to have the clutch-arm not getting the right leverage, and the current symptom is very different.

I'll post an update when/if I figure it out.

Hope to see some of you guys next October at the 928Int'l fest!

Dave