Clutch Grinding

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Franko

Franko

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The clutch grinds on my 1969 Dart 340, 4 Speed, when I fully depress the clutch toward the floor. I recently installed a McLeod Borg and Beck Pressure Plate. I believe that I have the clutch adjusted properly with 5/32” slack at the fork and 1” at the pedal. Has anybody else ever encountered this problem?

I have gone through all the components. The Bell Housing is 2892…482…70. I believe this is the correct bellhousing, even though it may be from a 1970 E Body. I have bought a new Clutch Fork (12 1/2” overall length), Fork Pivot, Clutch Linkage and a Z Bar.

I am attaching a couple of pictures of the larger Fork Pivot that I installed (measures 1 3/16” between the upright portion with the slot and the center of the bolt holes) and a smaller Fork Pivot (measures 5/8”). It appears that the larger Fork Pivot is correct, but it is odd that the smaller Fork Pivot was on all three 482 Bell Housings that have.

Any thoughts on whether these parts are all correct?

I have also attached a picture of my Throw Out Bearing. It looks like this after only about 10 seconds of grinding. It has no miles on it because I only ran my engine 30 minutes to break it in. I wonder if something is wrong with the Clutch Linkage/Throw Out Bearing/Pressure Plate geometry that could be the problem.

Thank you for any advice.

IMG_3500.jpg


IMG_3499.jpg


IMG_3506.jpg
 
I only run 1/4 inch free play at the pedal. As long as you don't ride the clutch that should be plenty.

Also, depending on the disc you run, you may need to run a bit more plate departure. For example, if you are running a rag disc, and it has a marcel spring between the two halves of the disc you may need .080 to .100 plate departure.
 
Clutch plates are normally marked with something like ENGINE SIDE, so check that while you have it apart?
 
I was dealing with a new clutch grinding problem a year ago.
Here is the long post about it. My problem turned out to be a pressure plate that was not set at the correct height when assembled.
New Clutch.....Problems
 
Is the car still trying to move when the clutch pedal is on the floor?
Disc in backwards, springs hitting flywheel bolts?
Discribe grinding noise.
 
I believe this is the correct bellhousing, even though it may be from a 1970 E Body
Click to expand...

The Bell Housing is 2892…482…70.
Click to expand...

That casting number was used on 1969 - 1971 A, B & E body small blocks with manual 3-speeds & 4-speeds.
 
A few people here said that my disc was in backwards, but that was not correct in my case. In fact when I pulled everything apart to install another clutch. I tried to install the disc in backwards and found out that it was impossible for the disc to lay flat on the fly wheel if it was put in backwards.
 
Grinding, the pressure plate is not pushing far enough to release the disk.
I had an issue once with a new clutch install, you could not put the car in gear.
It would go in gear with the car not running, start the car stab the clutch petal down, the rear tires would still turn, sitting on jack stands.
Pressure plate was junk.
 
With all the correct parts and the freeplay set,the pedal I'm guessing, only needs to go down something like 80/85% to achieve sufficient departure, to not have creep.
If you have to go further than this, and the grinding originates in the BH, then you are slamming the fingers into the disc, and it is likely worn out or too thin for the PP. You will have to take it all out.
 
AJ/FormS said:
With all the correct parts and the freeplay set,the pedal I'm guessing, only needs to go down something like 80/85% to achieve sufficient departure, to not have creep.
If you have to go further than this, and the grinding originates in the BH, then you are slamming the fingers into the disc, and it is likely worn out or too thin for the PP. You will have to take it all out.
Click to expand...


True also. The thickness of the disc changes the finger height.
 
From what you wrote I am guessing that the transmission is grinding because the clutch is not releasing cleanly? Or is it the clutch that is making noise? Either way, I always adjust my clutch by the air gap between the t/o bearing and the pressure plate fingers, a 1/4" or less. I installed a new B&B clutch and just adjusted the pedal free play and smoked the t/o bearing and damaged the pressure plate fingers. The free play felt good but there was no gap between the bearing and fingers.
 
Daves69 said:
Needs to explain the "grinding". Sounds to me he is over traveling the finger backsides into the disc springs.
Click to expand...
Sounds like it to a tee! That goes back to proper adjustment.
 
Daves69 said:
Needs to explain the "grinding". Sounds to me he is over traveling the finger backsides into the disc springs.
Click to expand...
When I removed the inspection cover and looked up there with a good flash light and a inspection mirror, I could see the the scrape marks on the face on the disc springs. I knew then that the pressure plate fingers were over traveling and hitting the springs when the pedal was pushed to the floor.

clutch spring.JPG
 
Thank you for your questions and comments.

I laid under the car with the inspection cover off while the clutch pedal was pushed with the engine running. The grinding is coming from the Pressure Plate or the TOB and not from the transmission. The clutch disc was installed the correct side toward the Flywheel. There is proper air gap and the clutch is properly disengaging. The car did not try to move with it in gear and the clutch depressed. I will also note that I aligned the Bell Housing for Bore Runout and Face Squareness.

The Pressure Plate is removed, but I can't see any scrape marks anywhere. I wonder if the fingers are adjusted evenly thereby pressing unevenly on the TOB.

Does anybody have any idea if the larger Fork Pivot is the correct one? Anybody happen to have a 482 Bell Housing pulled or one laying around?

Thanks again for your input.
 
List your non-stock parts. It sounds like your mis-matched pieces may be causing the problems.
 
Franko said:
Does anybody have any idea if the larger Fork Pivot is the correct one?
Click to expand...

With the pedal up, how much clearance do you have from fingers to release bearing? A taller pivot is going to reduce this.

Maybe this will help for the finger height...……...

FingHeightFix.gif


This "new" MP plate had one out .050" or so...…..

ClutchCover.jpg
 
The height of the fulcrum only affects where the fork is gonna sit in the window,after the departure is set. If the fork sits too far back, it will not have enough travel to achieve sufficient departure. If the fork sits too far forward then it is possible to over travel the TO and push the fingers into the disc.
Like I said earlier, you don't have to push the pedal to the floor. You only have to push it far enough to disconnect the engine from the transmission, so you can shift the dang thing. And if it does that at 50% pedal travel or at 80% travel it makes no never mind, as long as it gets done. Any more pedal travel than that is not helping, and if this applys to you, then stop doing it! lol.
To help you with the fulcrum height choice, I have the shorter one installed and it works perfect with my CenterForce and any disc I have slammed in there.
 
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Did I win something? Where are the scantily clad women with my trophy? Forget the trophy, just show me the girls... where are my shades...... Ok ready!
Honey, don't come in here, for a minute!
 
Daves69 said:
With the pedal up, how much clearance do you have from fingers to release bearing? A taller pivot is going to reduce this.

Maybe this will help for the finger height...……...

View attachment 1715218606

This "new" MP plate had one out .050" or so...…..

View attachment 1715218607
Click to expand...
Finger height? I had issues with a E bay set I put in. The second set from Brewers I had checked at Clutchmasters and was perfect and has been perfect ever since.
 
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