Clutch Do I have a clutch problem?

[shooby]

1978 CJ5 with V8 and T-18 Transmission . Hydraulic clutch. I see conflicting opinions on this but here goes:
When I try to put it in 1st or Reverse, most often I have to grind the gears. Yes, I put it in 2nd gear first and that is absolutely necessary but I still have to jam it to get it in reverse or 1st. Is this normal? I've been putting up with it for a few years now and after taking a better look at my clutch setup, I'm really wondering if there is something that needs fixin'.

 

[CJ]

Hey Shoobester...
What throw out bearing do you have?
What master and slave cylinder? (different / inappropriate bore diamaters can cause this)
What is the bearing to pressure plate gap?
Has this always been this way?

 

[Belizean]

We could have done it in the dirt and sand while doing my tank.

 

[shooby]

Hey Shoobester...
What throw out bearing do you have?
What master and slave cylinder? (different / inappropriate bore diamaters can cause this)
What is the bearing to pressure plate gap?
Has this always been this way?

Master is 7/8, slave is 3/4, the guy at Novak said that’s not a problem. Bearing to plate gap? Not a good time to be asking me that! I have the stock throw out bearing I guess. Do they make more than 1 for the CJ?
It’s been doing this for a long time. I switched to hydraulic a few years ago.
I’m trying to psyche myself up to do something about it.

 

[shooby]

Novak makes a nice slave with bracket but the bracket flexes. They told me that it does that because I have a 3 finger pressure plate.

 

[shooby]

Hey belizian, is that the ledge where my front wheels came up and I had to back down and take the bypass?

 

[Belizean]

That Bs the one. I had the perfect opening through the trees to watch. PM me your number if you want me to send the 2 pictures and 5 short videos

 

[Patrick]

You can rule out the hydraulic mechanism if it consistently and correctly fully disengages the flywheel from the pressure plate. You should be able to confirm this by observing the clutch pedal point of engagement during departure from a full stop.

We know your first and reverse gears lack synchronized engagement so you must come to a full stop before engaging them. You might just be engaging first or reverse too fast after depressing the clutch pedal and not allowing the momentum on the Transmission input shaft to stop. Remember, this is a heavy duty truck Transmission and is not designed for fast shifting. But it sure can transfer heavy amounts torque reliably. This might help you with your diagnostic departure point.

 

[flyn hawaiian]

Shooby. This might be a silly question . But what is the engine idling at? High idle will cause grinding with 1st. and rev.

 

[Patrick]

Didn’t mean to misinform or confuse anyone but I need to restate the following:

“You can rule out the hydraulic mechanism if it consistently and correctly fully disengages the flywheel from the pressure plate.”

I used pressure plate in lieu of clutch disc but surely you got my point.

 

[CJ]

I called @shooby and asked him to tell me me the gap from the flywheel / disk at full engagement.

 

[Patrick]

I am confused. You are probably referring to the gap between the throwout bearing and the pressure plate fingers when the pedal is at full rest and a fully engaged clutch…

There needs to be a very small gap to avoid premature throwout bearing wear.

 

[CJ]

I am confused. You are probably referring to the gap between the throwout bearing and the pressure plate fingers when the pedal is at full rest and a fully engaged clutch…

There needs to be a very small gap to avoid premature throwout bearing wear.

Yep, he has a borg and beck race PP. They are sensitive to release and engagement throw.
My advice, go with center force and be done...

Both and beck three finger...

 

[Patrick]

Don’t mean to drag on the subject but yes, there is one more important gap to be aware of and that is the clutch adjustment “air gap”. I wasn’t aware of it until I read some articles on clutches.

This gap is the amount of space that is created between the pressure plate friction surface and the clutch disc with the clutch pedal FULLY depressed against its stop point. If not adjusted properly, I can definitely see the clutch disc (which we know is engaged to the Transmission input shaft via the splines) never fully disengaging from the pressure plate resulting in gear grind and accelerated wear on the synchros. I will have to take a close look at my recently assembled new clutch components even though there are no symptoms.

 

[shooby]

Shooby. This might be a silly question . But what is the engine idling at? High idle will cause grinding with 1st. and rev.

usually idles at around 800 so I'm thinking thats about right.

 

[shooby]

I spent most of last year dealing with a bad AMC 304 and replacing it with a 360. Wish I would have put in a diaphragm pressure plate while I had it all apart.

 

[Patrick]

Your gears are grinding for one reason only: The Transmission input shaft is still revving during gear engagement. What if you move the clutch disengagement point earlier on the pedal travel…