The Stovebolt Site Forums The Shop Area Driveline Clutch problem

Just got the trans installed last night. Put in new clutch and pressure plate to bring you up to speed.

The clutch won’t disengage. I’ve got the clutch pivot arm adjusted as far out as I can go and it is still engaged.

Ideas

Doug

Did you put the clutch disc in backwards? That would do it!

Mike B

The thick part of the clutch disc center hub with the torsion springs in it MUST be pointed away from the flywheel. Otherwise, the springs drag on the flywheel attaching bolt heads.
Jerry

It’s installed correctly so must be something else.
The raised portion is in the clutch side.

Anyone have a picture showing that.


Doug

Do you have the correct length throwout bearing hub? There are about 3 different lengths, depending on the style of springs in the pressure plate assembly. It sounds like you've got a short throwout installed where a medium or a long is needed.
Jerry

Diagram

When you look from underneath, is the pressure plate moving? If it is, pilot bearing possibly sticking. Especially if it is a ball bearing type.

From the image you posted, I can't tell anything but when I swapped to the T5 I had to use a short throwout bearing. The long one would not fit at all and there was no middle sized bearing made for that kind of application. Turned out the OEM linkage rod was too long to let the other linkage rod connect and thread correctly--you hopefully can see how that would happen from the images attached. So I had to take a piece of 5/16" rod and bend it. Then it worked just fine. Good luck.

Question. When I put the clutch in position and snug all 6 bolts there is about 3/8” gap before I tighten it down onto the flywheel.

Clutch arm was adjusted all the way out to about an inch to spare. Seems way of if my memory serves me right. New everything should be somewhere in the middle of the adjustment range.

Doug

Do you have the parts you removed?

Thats the key there.
I`ve only done 5 or so clutches in my time and the old parts help a
great deal for this old Southern boy.

Doug,
How did you mount your T5?
Use a spacer block between trans & bellhousing?

Shorten input shaft & input brg retainer?

Swap input shaft for Jeep unit?

Not sure trans could be fully installed if not, seem input shaft would bind on crankshaft & make clutch a moot point.

It's a common problem for parts stores to provide the wrong pressure plate. That application requires a flat diaphragm
with a long release bearing. Anything else is going to cause problems.
Fred

Here are some pictures of the old and new clutches side by side.

There is enough difference in the plate thickness and clutch plate distance to flywheel to be a problem. Got the new clutch from O’rielly which was supposed to be for a 54.

1. Both clutches side be side
2. Old clutch distance from plate to mounting surface
3. New clutch distance from plate to mounting surface
4. Old plate side profile
5. New plate side profile
6. Plate profiles side by side

More pics
7. Side by side. Note differences in the center piece and that on the old one the plate is even with the mounting tangs and the new one is above the mounting tangs.
8. Notice the plate is higher on the new clutch vs the old one
9. Same

Doug

New pressure plate and clutch plate do not appear correct or even a close match.

The riveted sections on the pressure plate to me would cause additional problems with mounting to the flywheel.

Highly recommend you take them back and take your originals with you to see if they can find the correct match (or find a different vendor).

Dan

EDIT: It appears in the 2nd from last added picture that the clutch plate sitting on the pressure plate is "proud" of the pressure plate mounting bolt surfaces. It must sit slightly below the surface to allow for proper spacing from the flywheel face or it will stay in constant contact.

You can do better than that Doug.

Picture # 2 is measured in inches and comparison picture # 3 is measured in centimeters. Not all of us can do that conversion in our heads.

The new one you got is the latter style often called a beehive pressure plate. If you use the short TO brg with it it should work fine.
Are you putting in a T-5 trans.? If so there are some modifications you need to make. If you are not using a spacer you have to grind the splines back in the trans shaft.

George

Unless you wound up with a T5 from an Astro van or Camaro V8. Those had the correct length of input shaft so you don't need to grind anything. Probably the same for the V8 Firebird and Safari van. With the Astro van T5 you only need to get a clutch disc with the proper spline count (Astro will have a shorter bearing retainer and a 14 spline count), right size pressure plate (that matches your flywheel), the short TO bearing, ream the case holes a bit...and you may have to make a new linkage rod. The long TO bearing won't fit with those transmissions...or at least I couldn't make it fit at all. If you can find an 11 inch flywheel, there is a pressure plate and clutch disc that will work just fine. I'm certain there are other combinations, but I had the 11 inch flywheel out of a totaled 1954 Corvette and preferred the larger surface area.

Billl.. I didn't have my glasses on when I took those pictures so kind of missed the different scales...

Needless to say old methods are getting remembered now... I can remember bringing the old parts with me to the parts store to ensure this situation didn't happen... I've used the pilot bearing out of that kit so will see if they will do a refund without it and/or have a kit that matches what I need..

The plate being proud of the mounting surfaces should have been a dead giveaway but its been too many years since I've done any of this so didn't stop... my radar was pinging though when it didn't fit flush with the flywheel.... now I remember.. lol

Doug

Just got back from getting a refund at oriely's so happy about that.

Now just placed an order from napa that is supposed to be guaranteed to fit.. will pick it up Monday.... with the old one to compare it too..

fingers crossed.

Doug

As luck would have it the one at NAPA was the same. So no clutch atm.

Going to search some more.

Doug

I have been down that road with Napa also. Try to find a facility that rebuilds clutches and have yours rebuilt.
Fred

Is there anyplace that does that anymore. I felt lucky to find a machine shop that could resurface the flywheel.

I did find one that looks like it is what I need at carparts. Should get here Friday.

If someone does know of a clutch rebuilding shop let me know. That would be a backup if this next one doesn’t work.

Doug

Most of the rebuild shops have dried up, even here. I have had good luck with a source here in So Cal. He can provide the
correct clutch, either new or rebuilt. Clutches Unlimited in Midway City, CA. 714-373-6155. You will have to pay shipping.
Hope that helps, Fred

I ordered another clutch kit from carparts.com. It looked like mine but will have to wait until it gets here Friday.

If that’s a wash I found a clutch rebuild place in Kentucky I can sent it to.

It’s just another fight to overcome.

Doug

Clutch came in and doesn’t fit.
Boxed up the old one and took it to UPS this morning and should be to Kentucky clutch by Tuesday.

Hopefully I’ll get it back by the weekend and fingers crossed can move forward again.

Doug

It seems like 1954 was a year that GM made a lot of changes. Last year for closed drive line, 6 volts, ...

I found that I had to order a 1953 clutch for my truck after getting the wrong one. I called Precision Clutch and talked to a rep before I ordered the correct kit. He could tell me the bolt circle diameter and TO bearing size before the order was placed.

Like Gord said, there's typically a lot of carryover between certain model years. Currently, the next model year is available early in the fall. On my daily driver F250, there was a "99.5" model that happened in December of 98, and then in March of 99, more changes were made.
Here's the clutch pressure plate PN's. It says there's a break point between 53 and 54, but the actual build date of the truck, and how many of the old parts are leftover on the assembly line would make a difference when the actual change was made. Probably differs at each assembly plant as well.

I'm starting to see how the mid year change affects parts gathering.. Everything has to be fit checked and/or modified..
Well its keeping me busy and out of trouble.

On hold atm so heading outside to mow the yard..

Doug

10/31/23. Back in the garage. Have new pilot bearing, clutch and pressure plate installed.
This is the clutch that came with the truck. It is refurbished.

Trans is installed.

Still doesn’t disingage the trans.

What in the world can cause all new parts to not work.
Doug

Doug,

Do you have a helper that can depress the clutch pedal while you crawl under the truck and look at the mating surfaces between the pressure plate and flywheel (inspection covered removed) to confirm the pedal movement is actually lifting the pressure plate away from the clutch disc?

I read through this again & I still haven't seen were you have modified the T-5 trans. or are using a spacer or Jeep front shaft.
Your disc splines may be binding on the trans splines. Are you using a 14 spline clutch disc?

George

George,

Just a note that there is no T5 involved in this work. He is using an SM420 4 speed (as pictured).

Make certain you are using this fork...GM Clutch Fork Assembly #839240
also the orientation of the throwout bearing. Whether it may
have slipped off the fork or on backwards.
Have you ever driven the truck with the old setup?

Sorry. I kept seeing T-5 on page one.
I wonder if the engine mounted the way it is he may not be getting enough motion to release the clutch.

George

Doug,

Another question after rereading your entire thread. I understand you had the original pressure plate rebuilt so that shouldn't be the cause of the continued problem.

Did you use the "new" (different) clutch disc with the original pressure plate??? If you compare the 2 discs (I snagged copies of your earlier pics and added them below for easier reference), there is a big difference between the 2 which could be the root of your problem.

Worth investigating IMHO.

I'm with Gdads51... which clutch disk did you use with the rebuilt pressure plate? To work, it has to be a perfect match to the old one that was originally used with that pressure plate. They are a matched set. One cannot mix 'n match plates and disks.

Thats why I wondered if it even drove with this setup.
It may never have worked and someone just threw some wrong parts(PP ,CD) in there
before he got it.

T Doug... The clutch kit I installed in my 54 3100 is a Zoom MU 5469 1A. $145.00 from Summit.
Perfect match to the one I took out and perfect match for the one I took out 30 years ago.
My guess it is a perfect match for your old set-up.

11/2/23
Been too cold to do anything here. To answer a couple questions.

1. They refurbished the clutch and pressure plate so they are a match.

2. I did drive it with the old clutch a couple times around the block. It was slipping so bad I barely got it back into the garage.

3. The throw out bearing was a match for what came out.

Next I’m going to put the cover back on and make sure it is still in neutral. If it is I’m going to adjust the throw out so it is just off the fingers of the pressure plate. Then try again.

If that fails I’ll take a look at the one from summit.

Doug