T-Series clutch pedal vibration & noise

[NutmegCT]

Howdy - today I got in my 76B, pushed down the clutch pedal, started the engine, let it fast idle a bit, then lightly bumped the gas pedal to move to warm idle speed. Car had not been driven for several hours.

Just as I gave it some gas before backing up, I felt a slight "vibration" in the clutch pedal. Felt like someone holding the pedal to a bench grinder. No shaking or real vibration - more just a feeling in the pedal.

I hadn't yet engaged the gear. The "feeling" was accompanied by a slight grinding sound from the engine area, like hearing someone grind gears at a distance. Both the vibration and the sound disappeared when I let up the gas pedal.

I didn't drive it, fearing the clutch (bearing) was about to go out.

What disaster to my checking account is imminent?

Tom

 

[screenprinter]

I've not tinkered much with MGB's but I seem to remember they have a carbon block release "bearing" - If it has this original style "bearing" I'm not sure it would be making a grinding noise - Of course at some point in the past it may have been upgraded to a true ball bearing release bearing - That one might growl if it was breaking up -

My experience with Sprite clutchs (also Carbon block) is that when the release bearing fails the clutch just stops working.

If the noise occurred when you goosed it and quit when you let off it could be too many things to guess at - Look for the simplest first - Loose exhaust pipe vibrating against the frame/body - maybe a weak motor mount causing vibration.

Of course it could be your suspicions are correct and it is the clutch, trouble is you'll have to get the car to do it for an experienced mechanic to hear, or remove the tranny and inspect the clutch system - Not a particularly pleasant task.

As for the money end of it - it depends - If it is indeed the clutch and you're willing to do it yourself that really isn't too big a bite - If you find it's something more bizarre that a pro would have to remedy theres no telling.

Most of the time when you hear a noise once and it quits it's a fluke, it's when it occurs constantly and gets worse that you have to worry.

No doubt members with better diagnostic skills will be along shortly to offer their advice -

Good Luck!

Bob M.

 

[Guest]

Just a few words about my first experience with the MGB clutch.
I didn't know when I first got the car that it had a friction carbon throw out bearing so I used to keep the clutch pushed in at traffic lights. Mine was a pretty sudden thing. It started vibrating and making grinding sounds with the clutch pushed in and was OK with the clutch engaged and driving. Then the pedal suddenly went to the floor when I tried to push it and there was a crashing sound of metal and the clutch stopped working.
I was able to drive it home by starting the engine in 1st gear and changing gears very carefully by syncing the engine with the gears.
I knew I had trashed the clutch and ordered the new parts. When I took it apart I found the throw out bearing had completely ground off and fell off the fork and the fork had gone into the pressure plate and mangled the spring fingers and actually damaged the fork. The fork was not available but I was able to weld new metal onto it and grind it into the right shape for a new bearing. A new bearing, pressure plate, and disk fixed it.
It has worked fine ever since but I go easy on the bearing. It wll last the life of the clutch if you don't do what I did to the original.
Bob