Clutch help needed

[gadams]

car is a 77 930

I replaced the clutch,PP, T/O bearing and resurfaced the flywheel. Put it all back together and can not put into gear/go from gear to gear when the car is running.

I know the clutch is engaging and disengaging because I can start the the car with the clutch peddle pressed in and the trans in gear, if I let out on the clutch when the trans is in gear the car moves as expected and will stop when I push the clutch in and the engine will go back to idel. AM I overlooking something here?


when the engine is running I can not put it into any gear, it just grinds. I have checked and recheck the coupling between the linkage and the trans and it appears to be fine.

what am I overlooking, any ideas on what I am doing wrong?

I have followed the clutch linkage adjustment procedures, do I just need to adjust it more? I have adjusted it so far then the clutch never engages and still could not put it into gear.

Based on what I can tell the PP and clutch appear to be working engaging and disengaging


thanks for your help

greg

[gadams]

Problem fixed itself?

Not sure I know how or why. even though I could not put into gear without turning off the motor, I took it for a spin. The clutch held great but still could not go from gear to gear without shutting off the motor.

while I was out I stop turned off the motor put the trans into first gear, starter it up popped the clutch and went on my way. I pulled into the driveway said a prayer and tried second gear again and what do you know it worked. So I backed up and went for another spin and everything is working fine.


Glad it working but have no idea what changed.


greg

[Grady Clay]

Greg,

The symptoms you describe are typical of the clutch not releasing fully.

When you put it in gear first and then start the engine, the starter is powerful enough to overwhelm the sticky and/or not fully releasing clutch. While driving, the synchronizing rings are not sufficiently powerful to counter the dragging clutch.

Always a good (non-destructive) test is to carefully attempt to engage reverse when stationary. If the clutch is not fully releasing, you won’t be able to get it into reverse without it grinding. Don’t force it.
The difficulty with diagnosing this problem by shifting into the synchronized gears is that the two parts (dragging clutch and syncro friction) are trying to oppose each other. The stronger one wins. You can do serious damage to the syncros by attempting shifts with the clutch not fully releasing.


OK, what is (was) the problem? It is useful to try and figure out what is (was) going on here because it could be an on-going problem and damage your transmission or be an indication of something wrong with the new clutch parts or installation.

Some questions:

When you start it in neutral and then depress the clutch fully, can you put it in reverse without grinding (after a pause for the parts to stop)? Is it different cold to hot?

What clutch parts? OEM Sachs?

Did you test fit the disc on the transmission splines prior to assembling the clutch on the flywheel? Did you lube the splines on the transmission input shaft and in the clutch disc?

How much was the flywheel machined? Is it still in spec?

Did you use a tool to align the disc when you fitted the pressure plate assembly?

What other did you do in the clutch replacement process?


It is good that it seems to have fixed it’s self. The issue is why and what next.

Best,
Grady

[gadams]

Grady,

Thanks for looking and responding, answers to your questions are in-line

Some questions:

When you start it in neutral and then depress the clutch fully, can you put it in reverse without grinding (after a pause for the parts to stop)? Is it different cold to hot?
Now, YES hot or cold
Before it fixed itself, No hot or cold


What clutch parts? OEM Sachs?

sachs PP and TO bearing other clutch disk

Did you test fit the disc on the transmission splines prior to assembling the clutch on the flywheel? Did you lube the splines on the transmission input shaft and in the clutch disc?

Yes, I did test fit the disc onto the trans prior to assembling.

Yes, I did lube the splines on the trans and disc.

How much was the flywheel machined? Is it still in spec?

it was the 1st cut on flywheel and yes it is well within the tolerance (wear limit for turbo 9.9mm)

Did you use a tool to align the disc when you fitted the pressure plate assembly?

Yes, not sure how I could get the trans to mate with engine without using the tool.

What other did you do in the clutch replacement process?

Replaced the flywheel bolts, pressure plate bolts.


everything is working great, I took the car for another run this afternoon and it performed flawlessly.

I would love to find out why it acted as it did, it would help ease my mind. I defiantly do not want to break anything.


thanks for your insight

[Grady Clay]

Greg,

It appears you did everything as normal and proper. Good job.

What is the “other” disc? Is there anything about it that could have hung-up on the new Sachs pressure plate?

A test you might do is to see if there is any difference in sound with the clutch released and engaged when at idle and in neutral. Do this with the parking brake on. Of course there will be half the transmission rotating but you are looking for something scraping in the clutch when released.

Taking off from a stop, is the new clutch juddery?

Best,
Grady

[gadams]

Thanks for the sanity check.

I will test as you described and let you know the results
The clutch is an XYZ power friction disc. I compared it in size to the original Sach's disk and everything looked fine.

The clutch is not grabbing/jerking it works perfectly now.


greg

[Jim Sims]

Throw out bearing hanging up on an unlubed or worn throw out bearing guide tube? Groove edge (from previous throw bearing wear) that had to be worn off or broken? Jim