I recently had a new clutch placed in my 1965 Stingray. I have to push the clutch really hard all the way to the floor to engage. I am only 5' 5" so this is not easy for me even with the seat all the way forward. I have four other manual transmission cars and none of them are this difficult to engage. There is also a loud vibrating sound when the car is in gear and worse if I lightly touch the clutch. If I put pressure on the gearshift, the vibration stops. None of my other manual transmission cars do this.

I took the car back to the repair shop that did the work; they told me that everyone was fine and things should improve after "breaking in" the clutch.

I have driven @ 200 miles since the clutch was replaced and there has been no improvement.

Any ideas what I may be able to do myself to adjust the clutch would be appreciated. The car is up in Prescott for the summer and there are not very many good options for repair shops up there.

Thanks.

 

Ok got the video to load and that’s not good at all !
Something inside the bell housing is hitting something or rattling when you depress the clutch.
Almost sounds like the pressure plate is damaged, or not snugged up right, the clutch fork and throw out bearing are in wrong (can happen) or (from your description) something is warped.
That’s all I can think of.
So no adjustment is going to fix that, it won’t go away on its own and it’s definitely not normal.

 

Clutches don’t break in, in a manner that will address those issues. What brand clutch was installed? Is there a lot of free play with the pedal at rest? If so the clutch rod can be adjusted to reduce it to get the engagement point off the floorboard. But it won’t help the pedal effort.

 

What was the reason to replace the clutch? Did it operate properly with the old clutch? What brand and style clutch? Did they replace the bushing in the crankshaft?
It won't get better with miles IMHO.
Ron

 

sounds like that noise is somehow related to the throwout bearing touching the pressure plate fingers. that is NOT normal and it will never correct itself.

 

I agree. But a positive is that the car sounds extremely nice!

 

I had the sleeve of the front bearing retainer snap off and it was riding along with the throw out bearing. It wasn't making that type of sound, but it sounded more like a bad bearing. Yours sounds like the throw out is hitting the p-plate fingers, meaning it's not flat, it's likely not seated in the fork correctly. Could have snapped off one of the spring steel retainers. Either way, it's gotta come out and inspected.

 

If I were to make a bet on it, I'd say the bearing is not placed in the fork properly, or the fork is bad and thus deflecting (allowing the for to contact the fingers on the pressure plate). The fork not being properly installed on the ball, or the fork height not being properly adjusted, will cause an increase in pedal pressure. Either way, it needs to come back apart.

 

Here is what I know about the new clutch that was placed. I was told the old clutch was not the correct clutch for the car.

I brought the car in because it became almost impossible to shift; I could not get in reverse or third gear at all. The mechanic told me the problem was the clutch. Despite the other issues I am now having, once I engage the clutch, shifting is smooth between all gears.

Thanks for the comments. Sounds like I am going to have to find someone up in Prescott to take a look; I really do not want to drive my Corvette back down to Phoenix in the summer!

 

Sounds like I am going to have to find someone up in Prescott to take a look; I really do not want to drive my Corvette back down to Phoenix in the summer![/QUOTE]

@Vet65te might know of someone local to you.

 

My bet is someone installed the throwout bearing incorrectly. People like to install them wrong.

 

Gary - Sorry to hear about the shifting problems.
Sounds like there were clutch/shifting problems to begin with and problems still exist along with new problems after that shops clutch replacement. Something is definitely not right...somewhere, but with no details like what clutch was in there to begin with,
what did they replace it with, what was the condition of the flywheel, was it resurfaced when they did the clutch job (I expect they did do that), what did they find regarding the clutch and shifter linkage, etc.it's hard to play detective on this.
The other guys have already posed good questions, and it sounds like the shop that did the work is basically saying...we're done.
I asked a number of the local Car-Guys but since most of them do their own mechanical work, unfortunately, nobody had any shop recommendations to offer.
The local Chevy Dealer, Casa Chevrolet on Hwy 69, might be worth a visit. I only bring up their name because a few years ago, a friend, who's into early Vettes and Nomads, happened to be up there
getting his new Silverado serviced and saw a 66 L36 Maroon Roadster waiting for pickup after they did some work. Don't know what they did or how well they did it but at least it's a possibility.
There are a couple of 'Hot Rod Shops' in town that based on what I've heard, don't have great reputations and if you'd like to hear about them, send me a PM.
Wish I had better news for you.
Good luck.
Mike T - Prescott AZ

 

Could you share a picture of the clutch rod where it connects to the z-bar? It’s in the engine bay below the master cylinder. This is the adjuster for the clutch. With a new clutch, where the adjuster sits is important to this conversation.


Here it is circled in red.

 

Here is the photo in my Corvette. It is a 65 but not a "matching numbers" car. I have a 350/400 small block Chevy engine.

 

hope you didn't get a Hayes clutch.

@lars did a great write up on clutches needing to push no more than. 580" to get 0.050 separation of the disc to the flywheel.

 

I do not know what "brand" of clutch was used; I only know it was "period correct" for my vehicle and the old one apparently was not. I know the flywheel, pressure plate, and bearings were replaced.

A friend from the local Corvette club in Prescott referred me to Dunn's auto and tire, an "old fashioned" repair shop that can deal with an "old Chevy" as my friend put it. I spoke to the owner who can take a look at the clutch mechanism and at least diagnose the problem for me. Hopefully he can adjust the clutch tension so it is easier for me to drive and shift. If there is more than just a clutch related problem, I will probably be forced to bring the car back down to Phoenix to have it repaired.

Thanks for all of the groups input.

 

In my opinion, if you have a new clutch and the proper z-bar and rods, that adjustment is way off. It would cause the clutch to catch at the top of the pedal and perhaps have the TOB riding on the pp. seems the installer knew this as they adjusted it as far as they could and it’s still not right. If it’s the correct mechanical linkage and clutch, then an incorrect TOB was used or the TOB was incorrectly installed. I would start with the easy stuff by verifying the z-bar and rods are correct for your car. Someone will post the picture showing the differences and dimensions, I don’t have it. If the z-bar and rods are correct for your year and small block (big blocks were different) then you will have to pull the tranny to address the problem. Perhaps use an inspection camera to eyeball the TOB install first.

You mentioned the clutch you had was wrong for the car. Why? Did it not work, worn out, etc.? One of the many mysteries of these cars is “what was changed over the years?” You have a different engine. What else is different?

 

Why did Chevy make the BB z-bars different from the SB????

 

Mark is right - your clutch is adjusted way out nearly to the threaded end. So there is not much room left to adjust it away from the floor. You may need a longer upper or lower rod to get the adjustment off the floor. But I doubt that is why the pedal force is high. Possibly the TObearing is incorrectly hooked to the fork and dragging on the collar. But I think if that’s the case you would notice some roughness and catching when cycling the pedal up and down. I would call your mechanic and find out where the clutch came from and the manufacturer.




edit: But an improperly installed TObearing on the clutch fork could also contribute to the clutch releasing at the floor.

 

After you verify that you have the T/O bearing installed correctly and the correct cross shaft, you may want to look at the clutch you installed. I went through this several years ago. Not all clutch assemblies on the market today have the same release distances (can't find the right word). I went through two of them before I installed a Mac Leod clutch which fixed the issue. These Corvettes need a minimum of .580" (approx.9/16) to achieve a .050 separation of disc and P/P. c2vettehead mentioned this above. One of our forum members "Lars" wrote an excellent paper on this issue a few years ago. I followed it and fixed the problem. If everything else fails, you may want to look at this.