Screeching Sound

Don't know if this helps but my belts scream on start up if I rev the engine at all until the temp is above 160 the it never squeals any more.
Seems like the expansion of warmed up components stops the squeal.

Trannies grind. Belts scream.

Thanks guys. That’s interesting about the belt, I never thought that. I thought my clutch or a trans bearing was slipping or something.

Just thought I would mention that throw out bearings screech real load just before they seeze up. Don't ask me how I know that. It is still painfull to think about even twenty years later.

I had a screaching sound too, until I told her, "if you don't stop screaching, I'm not taking you any more"
Mark 6808

That damn screaching sure doesn't sound like the typical belt screach that I have heard in regular every day cars. It is pretty high pitch and only comes on underload such as after 1st to 2nd (never with just reving engine in neutral). Maybe throw out bearing, some other trans bearing or clutch plate? I'm lost. I get 1 - 2 screaches out of it on the first run, then ok after that. Maybe I need to drive more frequently.

Tires make a screaching sound when they spin. Try letting the clutch out a little easier.

Stop running over the neighbors cat Jan...

Brakes have been know to squeak or screach from rust or debris build up on the rotors from disuse.
It could also be the girls standing along the roadside too. Did you notice anyone waving and jumping up and down?

quote:

Originally posted by DOES 200:
.......... It is pretty high pitch and only comes on underload such as after 1st to 2nd (never with just reving engine in neutral). Maybe throw out bearing, some other trans bearing or clutch plate? I'm lost. I get 1 - 2 screaches out of it on the first run, then ok after that. Maybe I need to drive more frequently.

I had a V8 Vega with the same problem. It was the throw out bearing.

The culprit may be the pilot bushing. I had that symptom with a metallic bushing that had insufficient lubrication. The noise occurred under the conditions you described. The problem may have been exacerbated from several line bores my block had encountered over it's life. As a consequence, I surmise that the ZF input shaft may no longer be perfectly centered into the bushing causing pressure on the top side of the bushing. After replacing and lubricating the bushing, the noise went away - for now.

Good luck JT

The other day I noticed my clutch slave adjuster screw had turned inward noticably. So I backed out the screw and now no more screech. The pedal engages sooner too. Maybe this is all it was in that my clutch wasn't getting fully engaged. I am going to find a lock nut for that screw as I think it got that way on its own with vibration. I have a small nut on the screw now, but not a lock nut. Go figure, an easy fix for once?

Panteras are quirky cars to say the least.
I am amazed at what translates well and not at all into the 21st century.

I am impressed with the sturdiness of most of the car.
Many things that I take for granted such as the clutch slave are actually very substantial.

Compared to todays cars it is beefy in a way that will never be equaled again for a production car.

Other things, seemingly simple, like making the tach work with a solid state ignition are puzzling.

All things considered, I'm more impressed today with it then 5 years ago.

It may turn out to be the all time, best-bang-for-the-buck-car ever built.
That's also it's biggest curse and attrcts the wrong buyers. It simply isn't exclusive enough for the higher rollers.

I don't think that clutch slave adjustment screw is doing you any favors? I think it was one of the old technical service bulletins that said to remove it? I do not use it on my car. All it seems it would do is to reduce the free play in the system without providing any benefit. If there is enough free play in the system, it seems like you could relocate the arm on the shaft to gain more clutch release which sounds like a good thing.
Art

quote:

Originally posted by DOES 200:
The other day I noticed my clutch slave adjuster screw had turned inward noticably. So I backed out the screw and now no more screech. The pedal engages sooner too. Maybe this is all it was in that my clutch wasn't getting fully engaged. I am going to find a lock nut for that screw as I think it got that way on its own with vibration. I have a small nut on the screw now, but not a lock nut. Go figure, an easy fix for once?

Art,

I thought I had all the bulletins and have never seen any that indicate the free play adjustment screw should be removed. Do you recall the bulletin number? If the screw is removed you will have too much free play and that will reduce the amount of movement needed to disengage the clutch fully.

Mike

I have no idea why anyone would suggest to remove the adjusting screw on the clutch. If you do this, you will have way too much free play in the clutch and may not get adequate disengaugement resulting in syncro wear. There is no substitute for a properly adjusted clutch. Except for the Internal slave cylinder, which I happen to use and it works great.

Mike,
I am not at home so I can't look at my car or my manuals. I think the word "discard" is used in reference to the screw? This may be in the repair manual? I will see if I can find it when I get home. On my car, if I am not mistaken, the screw could only take up free play and would have no affect on disengagement because the rod coming out of the slave is attached directly to the lever that is attached to the shaft going into the trans. The only way I can see the screw affecting disengagement, would be if the screw was like three inches long and screwed all the way in, completely disengaging the clutch. Then of course you couldn't drive the car because you could not engage the clutch. I believe there is more than one type of adjusting screw bracket, I think there is a one piece and a two piece? But on #4268, I think this is the way things work. I may feel like an idiot tomorrow when I go have a look, I'll let you know.

Art

quote:

Originally posted by www.PanteraPlace.com:
Art,

I thought I had all the bulletins and have never seen any that indicate the free play adjustment screw should be removed. Do you recall the bulletin number? If the screw is removed you will have too much free play and that will reduce the amount of moment needed to disengage the clutch fully.

Mike

I believe I can adjust out all the free play in my clutch with no adjusting screw. I simply lengthen the adjustable length rod being pushed by the slave until all free play is gone. This should also maximize my clutch disengagement, right? I realize some free play is required to keep from wearing out the throw out bearing.

"I have no idea why anyone would suggest to remove the adjusting screw on the clutch. If you do this, you will have way too much free play in the clutch and may not get adequate disengaugement resulting in syncro wear".

quote:

Origi

It may turn out to be the all time, best-bang-for-the-buck-car ever built.
That's also it's biggest curse and attrcts the wrong buyers. It simply isn't exclusive enough for the higher rollers.

That's a little elitist isn't it? What does a "wrong buyer" look like?

Miles

From my experience working with owners, I think the Pantera hydraulic clutch system is one of the most misunderstood parts of the Pantera. When all the parts in the clutch system are functioning and adjusted correctly the system works excellent. On the other hand if the adjustments are off it can be a mess! And if the wrong clutch plate and cover are used it is a super mess.

The amount of movement that the slave can move is pretty well fixed by the piston area ratio between the master and slave. There are some adjustments at the master and pedal linkage, e.g. how high the pedal is set, free play between the push rod and master piston, that can impact movement but most of the adjustment problems are usually found at the slave end of the system.

The adjustable stop serves a number of functions:

1. Provides an adjustable free play stop at the closest point to the throw out bearing.
2. Prevents the slave piston form bottoming out in the slave bore and causing damage to the piston or bore.
3. Sets the starting point for the hydraulic fluid self adjusting movement starting point.

Because the total slave movement is fixed by the piston ratios the more free play you set with the adjustment stop the less of the fixed movement can be used to disengage the clutch. Here is a page on Pantera Place that might be helpful in understanding how to adjust the free play http://www.panteraplace.com/page124.htm

Mike

Mike,
I found it. On page 16-02-03 of the Pantera Technical Information manual, in the Adjustments/Clutch Pedal Free Travel section, #3 sentence reads, "Remove the adjustment stop screw and nut and discard".
Art

Art,

Very interesting! Hadn’t noticed that sentence before. My copy of that manual was printed in September 1973. TSB 10 is dated January 25, 1974 and says that it “supersedes all previously published information on the subject”. Apparently after removing the stop screw Ford decided that the Italians were smarter than they thought and put it back. Expect they ran into problems with the slave piston bottoming out in the slave bore. Interesting conflicting information.

Mike

Makes sense Mike. I am thinking that when a guy installs a new slave, he would be better off eliminating the adjusting screw. With a new slave, there would be no buildup of crud that would damage the seals and he would then be able to take full advantage of the range of motion the new part has to offer. Bigger is better here, right? That is why vendors offer the long throw slave, no? It just seems to me that the downside of the stop screw is that it reduces the hydraulic systems range of motion and I think we want all the range of motion we can get. Does this make sense, or am I missing something? (It certainly wouldn't be the first time)
Art

While we are on the subject let me ask a question.

Many current production vehicles with manual transmissions are designed with self adjusting clutchs.
The signifigance of that to us means that on those vehicles, the throwout bearing is in constant contact with the clutch cover fingers.

The clutch replacements I have done on those cars all use the same type of throwout bearing design as the old school cars like the Pantera.

The fingers of the clutch do all show wear from the constant contact. They last as long as any clutch because it is normally the center disc lining that wears and makes the clutch replacement necessary.

All things considered, why can't the Pantera clutch, throwout bearing, be adjusted for zero clearance? It certainly would help this lack of total travel problem that the car routinly suffers from.

Art,

The range that the slave piston can move is fixed by the ratios that I discussed in my earlier post. Not much you can do to change that and the stop screw does not interfere with the movement. My system is all stock parts and from an idle with the ZF in neutral, I can depress the clutch and shift directly into reverse. It’s a good test to see if the clutch if fully disengaging.
------------------------------------
PanteraDoug,

The clutch needs enough free play available in the system to allow for the small amount that the clutch fingers will move back at higher HPMs because of the centrifugal aspect of the clutch mechanism. At one time Pantera Performance in CO sold a constant contact bearing.

Mike

I would think so also but I have two vehicles here, a Taurus SHO and a Contour SVT.
They both use the Ford self adjusting cable clutch and both use diaphram pressure plates.

They are both zero clearance.

How do they work then at high rpm? They certainly don't slip and they certainly see real rpm.

I know what you are talking about with the rpms with a diaphram clutch, yes.
I put a Centerforce dual friction in my Shelby GT350.

The clutch pedal actually pushes back somewhere over the 5,000 rpm area. It's a little freaky.

The racers told me it would do that. I never heard of a Long clutch doing that though.

I certainly have no experience with that happening with the long.

My 280Z, two 300ZX Turbos and my Maxima all had self adjusting hydraulic clutch linkage systems. That is they were self adjusting after you set the master push rod free play. I’m pretty sure the throw out bearings were designed so that they could have some prolonged contact with the clutch fingers. The only clutch linkage return spring was at the master end of the system. Apparently the systems relied on the clutch fingers to push the throw out bearing back enough for some clearance. Because of the way that the master and slave work together it will automatically take up the slack as the clutch plate wears. On the Pantera however many unmodified ZFs have springs on the clutch finger shaft that pulls the throw bearing back from the clutch fingers along with the spring at the slave. Those springs along with a throw out that is not designed for prolonged contact make the adjustable stop desirable.

Many long type clutch covers have weights on the clutch arms and I expect even without weights they add clutch plate pressure at higher RPMs. Of course the ones with the weights they will not fit inside the ZF bell housing.

Mike