New Clutch.....Problems

-
694spd

694spd

Well-Known Member
Joined
May 2, 2014
Messages
1,219
Reaction score
504
Location
Upstate NY
I installed a new "factory replacement B&B clutch" and did a preliminary adjustment of the rod to the clutch fork so to have a little clearance be the release bearing and clutch fingers.
With the engine off the pedal feels fine when pushing it to the floor and through it travel. When I started the car and pushed the pedal to the floor I heard a scraping sound and I could feel it in the pedal.
I tried to shift it in to first but it did not want to go in.
I shut the car off and was then able to shift into first. I decided to start the car in gear, so I pushed the clutch to the floor and hit the starter. The car started to lurch forward and again I heard noise that sounded like grinding.
Is this being caused by the clutch not being adjusted correctly? If so, which way do I have to go on the adjuster.
 
Pull the fork boot off and maybe even the fork, see if you can get an eye on the bearing. Do all the plate arms look even against the bearing? if not it`s possible an arm roller dislodged and is causing your grief.
 
Here are pics of the assembly. As I recall the disc has a marking "Fly Wheel Side" on it as most disc's do. Looking at the pics I do not see that marking so I believe that it is in correctly. The throw out bearing came with the clutch kit, so it is new. I bought the set up from Rock Auto looking for just a stock clutch.
When I was installing transmission, I had some trouble getting it aligned up and it took me several attempts to finally get it in. I'm hoping that I did not damage the disc trying to find the center of the hole.

100_4271.JPG


100_4272.JPG


100_4273.JPG
 
Flat(er) side of disc to flywheel. If it's in backwards you also risk bending it.
If it's not in backwards and you over drive the release bearing it's possible to run the backside of the plate fingers into the disc springs. This will also produce that noise.
 
Think of it like a hat , sitting flat or brim side on the flywheel. I admit I installed one upside down once, argued the whole time I didn't, tore it back apart and sure enough...
 
Starting point should be around .060" gap with the pedal depressed fully.
ClutchAdj.jpg
 
You'd have to be pretty ham-fisted to damage the clutch disk installing the transmission, usually once you finagle the splines and the pilot bearing together usually it's smooth sailing from there.
It's hard to tell from the pics but what do the fingers look like on the pressure plate when bolted up to the flywheel? The clutch disk looks like it's in right, but it almost looks like the fingers are sucked into the pressure plate, might just be the camera angle but it almost looks like they're too deep, like the finger height isn't set right, which will cause grinding and release problems.
 
Last edited:
It looks to be in the right direction. What type clutch did you replace? Did you install a matched clutch set? The TOB are different from B&B to diaphragm.
 
if you had trouble inserting the trans, it is possible to "hang" the transmission from the splines before it is inserted completely in the pilot bushing. All that weight and that huge lever arm can put a hurt on the hub. If this happens the clutch disk hub can get bent.
Have you made sure you have the correct throw out bearing, and that it is turning smoothly. I used to love Borg Warner Power Brute throw out bearings. Don't know if they still sell them.
I agree that the picture looks like the lever height is too low. could be an optical illusion.
 
Did you compare the replacement parts and the old parts to verify dimensions ? I notice a Korean clutch disc and a Mexican pressure plate .............
 
I've seen flywheels turned too much and the springs hit the flywheel bolts or a replacement bolts head too high /sounds like its coming back out for a inspection anyway
 
From all the replies, it sounds like adjusting the linkage will not correct my problem?
The car was raced back in 1974 then parked and has not move under its own power in 43 years.
I The clutch that I removed was a Schhiefer Borg and Beck. The new clutch kit that I bought from Rock Auto was sold under the name Valeo.
It beginning to sound like I will have to pull the tranny back out. Not looking forward to that.
 
694spd said:
I installed a new "factory replacement B&B clutch" and did a preliminary adjustment of the rod to the clutch fork so to have a little clearance be the release bearing and clutch fingers.
With the engine off the pedal feels fine when pushing it to the floor and through it travel. When I started the car and pushed the pedal to the floor I heard a scraping sound and I could feel it in the pedal.
I tried to shift it in to first but it did not want to go in.
I shut the car off and was then able to shift into first. I decided to start the car in gear, so I pushed the clutch to the floor and hit the starter. The car started to lurch forward and again I heard noise that sounded like grinding.
Is this being caused by the clutch not being adjusted correctly? If so, which way do I have to go on the adjuster.
Click to expand...
Maybe you just pushed it too far? and the fingers got into the springs.
I know on my 1969 linkage and at 1/2 to 1 inch freeplay the clutch is separated at about (guessing) 80% of the available pedal travel. There is (guessing again) about 1 to 1.25 inches at the bottom of extra travel that I never use.
If you HAVE to use all of the travel,that's a good indicator that the clutch departure is insufficient, which kindof speaks to a bent disc. And the grinding is proving it......... unless; your TO fork is too short, or it is incorrectly installed, or the Z-bar is wobbling around.
The Z-bar has to be anchored at the outboard end by that fancy wire clip deally,To prevent lateral movement. And the frame anchor needs to be welded. And the bushings need to be in reasonably good shape.
The pushrod from the Z-bar to the fork should be approximately parallel to an imaginary line drawn through the center of the car,in plan view.
The TO fork needs to be engaged by both clips on the TO bearing carrier.
The fork pivot needs to be of the correct height to put the outboard end in the correct working relationship.

And the trans needs to be sucked right up tight to the bell and the input shaft not jammed into the back of the crank,lol. Sometimes the tip of the input has to be cut off to fit into an automatic crank. If the input is jammed into the crank it won't stop spinning. But I wouldn't think would make a grinding noise. At least no one who has had this problem, reported a grinding here on FABO.
The lurching forward on start-up, in ear, as you describe, could be either; either the lack of departure, or a jammed input. Or, I suppose; a gear seizing on the M/S, or the tranny stuck in two gears, but those aren't supposed to happen,lol.
 
I'll bet it's the clutch fork.
A-Bodies take a 12 1/2'' fork and most others take a 10 7/8'' fork measured in overall length.
If not that, take a look at the bell crank (or z bar) to see if it's been modified.
If it was an ex race car, there's no knowing what they did to modify the linkage and or mounting points.
Check out brewer's performance website, there are lots of specs and pictures on there...........
 
The z bar and fork and trans are all original to the car. I won't be able to get the car back on jack stands until tomorrow. So that's is when the investigation will be starting again.
 
it's been many, many years since I've been into a 4spd, but I kinda remember there being two positions for the fulcrum of the throw out arm. As i recall, the fulcrum is bolted into the back of the bell housing, and there are two set of holes. I might be conflating another app, so I'm not positive, but it might be worth taking a look when you're back in there.
I agree with the previous poster to take this opportunity to take a close look at your clutch linkage. Make sure everything is in place and in good working order. The geometry is important. You want the zbar perpendicular to engine centerline. You want the arcs of the arms to be centered in their travel.
 
694spd said:
The z bar and fork and trans are all original to the car. I won't be able to get the car back on jack stands until tomorrow. So that's is when the investigation will be starting again.
Click to expand...
the oem zbar is pretty cheaply made. It's OK for stock clutch assy, and normal driving, but you start throwing in heavily sprung pressure plates, and power shifts, and things start bending.
 
694spd said:
...........I won't be able to get the car back on jack stands until tomorrow......
Click to expand...

FWIW BTW, that .060" gap, probably better to sneak up on it than adjust back to it. So I'd back off the adjustment and then adjust to it.
Other items to look at prior to removal...
- both release bearing spring clips correctly on the fork
- fork all the way on the pivot
- rearward force by hand on the fork should cause the release bearing to contact the three plate fingers simultaneously
 
Passon Performance makes aluminum boxes. I have one. I think the fully assembled b
box weighs 85 pounds. It goes up like nothing. Down in 17 minutes,up in a few more.
If you don't already have one, the 3.09 gearset is awesome.................with 3.55s
 
I got the car back up on the stands this morning and removed the inspection cover. Look at the face of the disc using an inspection mirror. I could see that the pressure plate fingers had come in contact with the clutch disc damping springs. See arrow in 1st picture.
It pretty obvious that when the pedal is at the floor I was getting too much plate departure or at least over traveling the fingers.
What bothers me some is that not all of the springs made contact with the fingers. Some were had a fair amount of scrapping while others had none.

The FSM says that the the free play in the linkage should be 5/32" at the end of the fork. I had much less than that. 5/32" seems to be quite a lot. I have it set now at about 1/8" and I'm getting a gap of about .050" between the pressure plate and disc with the pedal to the floor. See arrow in 2nd picture....
I think it is time to put the car back on the ground and give clutch another try.

100_4485.JPG


100_4486.JPG
 
You must log in or register to reply here.
-

Back
Top