cluth shudder when coast at low speed
 

Hi all, car is an 82 SC. May have original rubber centered clutch (not sure; car supposedly has only 71k miles). Car runs, drives and shifts great. Clutch cable professionally replaced only 1k miles or so ago by PO. All motor/trans mounts replaced recently by me.

I noticed that when I coast (foot off gas and clutch) at low speed -- 20 mph or so in 2nd gear, like when I enter a school zone -- I can hear the clutch shudder or chatter. Car also hesitates slightly with each shudder. All this immediately goes away if I give it any amount of gas or if I press clutch. The shudder never happens except when I coast at low speed like this. I did some searches and sounds like this could be release bearing? I've done a fair amount of DIY stuff on various cars but never had to deal with clutch. Thanks

Might not be the clutch, under that small of a load and it goes away when you give it gas, sounds more like the injection system. Does it slip at rapid acceleration/deceleration? the throwout bearing is not in play with your foot off the peddle. Try pushing in slightly the clutch when this happens again. See what happens. You might not have the rubber centered clutch, depends how many were left on the production floor, they started to be phased out in 1981. Looking in there is the only way to be sure.

the clutch does not slip under load. when it is shuddering like that I can floor it and the shudder will immediately stop and the car will take off like a rocket (well, as much like a rocket as an SC can muster). I didn't realize they started to phase out rubber center in 81 MY. Mine was build Sept. 1981 (1982 model year).

It's a crap shot if you have one or not. try just gently accelerating when you experience this harmonic next time and see if it goes away.

If it makes you feel any better, my '86 Carrera does EXACTLY the same thing! It's been doing it for about a year now. For a long time I thought it was a noisy rear wheel bearing, but clutch chatter makes more sense as it always goes away when I do one of two things:

1. Disengage the clutch.

OR

2. Give it some gas (even just a tiny bit is enough).

Is this something to be concerned about?