Hot Rods This problem has me scratching my head

I had a car in the shop that had a new clutch with the same problem, adjust the clutch and drive it and it would progressively stop releasing, adjust the clutch and it would be fine then after driving it stopped releasing as before. turned out the new clutch was too stiff for the rod between the clutch pedal and Z-bar. once it started to bend it became weaker and weaker. I made a more stout rod to solve the problem.

 

Same with the Z-bar, over the years the factory welds start fatiguing, after rewelding, some reinforcements should be added.
From the internet

 

It was called out in internal confidential memos at GM as the cause for NWC T5 failures, resulting in excess warranty replacement claims, and much of the poor reputation of that transmission model.

No, I don't have pictures.

 

There really is not a debate about the effects of the Sulphur concentration in GL-5 lubricants.

Chemistry is governed by the Laws of Physics. Those are not open for debate, and opinions do not change that.

Exposure time and heat exacerbate the effect.

 

What I was saying is that didn’t cause the failure he’s experiencing, maybe it does do as you say, I’ve never run one long enough to experience it, even after many years. Lucky I guess

 

It wouldn't hurt to look at the clutch linkage from A to Z.

I chased an issue on a '64 Ford with a HD clutch. I was around 22 at the time and we diagnosed it as a collapsed TO bearing.

Pulled it all apart, the TO bearing was fine. Someone finally sees that the z-bar had one leg at a weird angle. We fixed that up, ordered a new one at the local dealer.

 

Wouldn't hurt to check the pivot ball on the block side while you're at it. I've had 'em crack and eventually fail...

 

I can see where the gear lube being wrong can have a long term effect on the function of a transmission, but if 20 miles with the wrong gear lube cooked the trans, it was junk before the wrong gear lube was added. Someone just had the bad luck of installing a new clutch before the trans died. If it a trans problem, it will still have the problem with a cold run test in the driveway.

Unless the OP has failed to tell us about all the power shifts that happened in those 20 miles.

I'm feeling a linkage or clutch/pilot bushing issue is the current problem.

 

SILLY, but did you put clutch disc in backwards ?

 

Not proud of it, but I have made that mistake.

 

So easy to do, along with the T/O bearing and fork interface.

 

I was with my brother in his old GMC 1-ton and the pivot sheared off. It was a rough ride home, starting the truck in 1st gear... in a Hollywood down pour no less.

I've seen the z-bar tear where the ball pivot nests.

 

With the Mopar performance stuff I used to deal with, you had to work really hard, or didn't pay any attention at all if you put the clutch disc in backwards, you could barely get the pressure plate bolted on, the disc was against the flywheel bolts (or, maybe I was lucky and tried it with just the one with the stubborn disc & pressure plate assembly ).

I did have a Z bar self destruct once, in a traffic jam at the Car Craft Nationals in Indy. That was quite a deal. I managed to get it stuck together enough to work long enough to get us through the weekend and back home, with a borrowed welder and welding rods that were sitting in a can of water! Once home, I built a new Z bar for the 65 Barracuda with a v8 4 speed, cause I sure couldn't find a good Z bar for it in 1984.

 

MORE THAN ONE PERSON HAS:
some just won't admit to it !!!!!

putting clutch disc in backwards ,
Not proud of it, but I have made that mistake.

 

Truth.

 

I put the clutch disc in backwards.
Once.
I doubt very few do it a second time.
Cuz it's no fun kicking your own ass!
LOL