Ford Mustang Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
59 Posts
Discussion Starter #1
Hi,
I have a 1968 302 with a 3 speed and while the engine is rebuilt I can't say what kind of condition the transmission is. I tried to put the car in first gear with the engine running and there was this horrible grinding noise which i took to be the gears grinding together. I didn't want to force them because I was afraid I would damage them. So my questions is what could this be? The clutch and flywheel are the original, unfortunately. But the clutch disk and throwing bearing are new. From what I've heard I was thinking it could be the syncro gear or maybe the linkage isn't set up quiet right. I appreciate your in put!
 

·
Registered
Joined
·
206 Posts
Yea, would point to clutch. first gear normaly does not use a synco. sounds like clutch does not disengage all the way.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #4
thanks for your quick replies. That makes sense that the clutch isn't disengaging all the way. The pressure plate is not new, so I will look into a new one. The plate relies on springs though correct? So if it was old wouldn't it disengage easier because the springs would be softer? I'm just trying to understand it better. Does anybody have a diagram of the correct linkage set up so I can compare it to mine?
 

·
Registered
Joined
·
2,905 Posts
Hello 68coupe5.0,
When I come across an issue on the car, I try to investigate
and determine where the problem is. Often times there are little
tests that can be done to help diagnose.

I am not certain I fully understand the trouble but I am thinking
you have a noise as you try to shift. This would indicate as others
have said an issue with the clutch components or the trans and linkage.

It is often hard to describe a noise as well. There are quite a few things
that could cause a noise as you describe. I will list a few for examples

1. - Throw-out bearing dry/going bad
2. - Bad linkage and the trans grinds
3. - Clutch no engaging etc.

Here is what I would likely try next BEFORE you tear things apart.

Do this with CAUTION. If you can - -move the car to an open area or at least
an area where it can move without hitting something.
2. Then PULL the coil wire - -so the car will NOT start.
3. - With the motor OFF - -shift into first gear.
4. - Remember the motor is NOT running at this point
5. - STEP on the CLUTCH pedal and turn the key for a second. PLEASE keep in mind this is NOT good for the starter and should only be done once.

With your foot on the clutch pedal - -turn the key. The car should NOT move but may if the clutch is NOt engaged. If it is not engaged then time to check the linkage
etc. Then you may need to check a bit more and may have to drop the trans.

Start with the easy stuff first.

Keep IN MIND - - the car may want to launch forward and after the test - reconnect the coil wire.

Print Dad
 

·
Registered
Joined
·
59 Posts
Discussion Starter #6
Thanks print dad that seems like a good way to see if the clutch is engaging or not. Unfortunately the engine isn't in the car right now. I found some pictures of the clutch linkage so im going to check that out and make sure my linkage matches up. While the engine is out is there anything else I can check? I'll send pics if anybody would like. I'd hate to put the engine back in a and then have to take it out again.
 

·
Registered
Joined
·
2,905 Posts
Hello 68coupe5.0,
Many thoughts here.
1. - You can easily install the clutch and trans from under the car
so I would go ahead and re-install the motor and leave it alone.
Yes many people, myself included assemble the entire unit (motor and trans) and drop
it into the car. I have countless times done a clutch from under the car.

2. -PLEASE be sure to have the car properly supported on jack stands etc.

3. - Not sure if this will help or not but I will try to explain the clutch in pretty simple terms. when your foot is NOT on the clutch pedal, the clutch disc is forced
between the pressure plate and flywheel causing a situation like a solid unit. The motor
turns and this turns the flywheel, clutch and trans.
When you step on the clutch pedal you are putting pressure on the fingers of the pressure plate. When you do that - -it "releases" pressure on the pressure plate
which causes the clutch disc to be able to turn freely.
I hope the pix helps giv e alittle better understanding.

So you step on the clutch - -the force is headed towards the ront of the car. It hits the "equalizer bar Z-BAR" and makes the force head towards the rear of the car.

The Z bar has a rod that goes to the arm that holds the throw out bearing.
When the forces is applied to the arm - it is headed toward the rear of the car BUT
the arm acts like a fulcrum and shoots the force back towarads the front of the car.
As this for ce is applied it forces the "throw-out" bearing to push the fingers on the pressure plate. When that happens the clutch is disengaged.

I hope that makes some sense

So it would seem to reason that your problem is the linkage is not set up properly or the pressure plate is bad. If the pressure plate looses the ability to release pressure
from the clutch - it will be like the clutch is tight on the system all th time.

My Advice - -I would swap the pressure plate while the car is apart.

I would also like you to know - -doing the job under the car is NOT too hard. The trans is pretty light and can be put ino position pretty easy ising an aligment tool.

As far as checking the trans - -The best advice I think I could offer right now - is to shift the transmission into first manually while it is out of the car. Turn the input"pilot" shaft and see if the tail "output" shaft turns pretty freely. NOT a great method BUT itis my guess the trans is OK

Please let me know if you need more help on the install. I will look for linkage pictures later.

Print Dad
 

Attachments

·
Registered
Joined
·
59 Posts
Discussion Starter #8
Ok thanks that actually helps a lot. That's how I thought the system worked but it just isn't for whatever reason. I'm fairly certain that the linkage is set up right. I mean there really isn't too many ways it can be set up right? I think your right in that the pressure plate needs to be replaced, it's old and I don't know anything about its history. So I will replace that and let you know if that solves it. I with you that replacing it from under the car isnt difficult, but I'd rather get it done now so I can drop the engine back in and drive :bigthumbsup
 

·
Registered
Joined
·
138 Posts
Ok thanks that actually helps a lot. That's how I thought the system worked but it just isn't for whatever reason. I'm fairly certain that the linkage is set up right. I mean there really isn't too many ways it can be set up right? I think your right in that the pressure plate needs to be replaced, it's old and I don't know anything about its history. So I will replace that and let you know if that solves it. I with you that replacing it from under the car isnt difficult, but I'd rather get it done now so I can drop the engine back in and drive :bigthumbsup
Sounds like you need to check the clutch adjustment. There should be about an inch of "free travel" (slack) in the pedal. If you have too much free travel the clutch will not disengage and it will grind when you try to shift into gear. If the free travel is OK, the problem could be that the disc is warped. This can happen when you are trying to put the transmission on. Sometimes the transmission wont go all the way on and people will let the transmission just hang there while they try to figure why it wont go all the way in. This can warp the clutch disc which will ruin the disc. If that happens, the clutch will not disengage even when the pedal is all the way down.
 

·
Registered
Joined
·
4,555 Posts
They have given great advice, do the adjustment first, if you have not touched the adjustment, it needs to be lengthened. Also it is good practice to replace the clutch plate when replacing the clutch, sometimes they lose some clamping tension. When reusing the clutch plate and flywheel if you don't get them resurfaced at least break the glaze with some emery cloth or sandpaper, going at about a 45 deg angle to the circular lines on it, I know it's too late for that now, but fyi. Also put a small amount of high temp grease on the sleeve the throwout bearing rides on the front of the transmission. Good Luck.
 
1 - 10 of 10 Posts
Top