Pre-war (up to 1942) Stuck clutch after engine replacement

[dawicker]

I replaced the engine in a 1936 series 70, and the new engine runs great, but the clutch won't disengage. In the shop manual, they warn if you don't keep the engine and trans aligned, you can "spring" the clutch disk. I didn't think they got very misaligned, but when you are shoving and shaking to get it together, who knows. I was hoping the shaft just needed lubrication ( I didn't lube this beforehand, maybe a mistake?) but I removed the inspection plate in the bell housing and squirted some penetrating fluid on the shaft, but no difference. Does anyone have any suggestions short of removing the trans? I was thinking I might be able to try pulling the disk away from the flywheel with the clutch pedal depressed just to make sure it moves, but don't really see any way to do this through the inspection opening.

The new engine came with a trans attached (and both worked, as I drove the vehicle), and the existing trans previously worked fine, so it is something I did (or didn't do). How easy is it to spring a clutch disk? I was originally going to replace both the engine and trans together, but someone convinced me it it easier to replace only the engine, which it was, but opens up this can of worms

Dave Wicker

[LaSalle5019]

Are you sure you are getting enough lift of the pressure plate? You should have about of inch of free play at the top of clutch pedal travel and then resistance the rest of the way down. Watch the plate lift off from below while you have someone depressing the pedal (engine off).

I assume you can start the car in neutral but after depressing the clutch does the transmission just grind when trying to shift into gear?

You should have a pilot bearing and you wouldn't be able to draw the trans up if the fit was incorrect. If you don't get the splines on the disk aligned with the input shaft it would be very apparent that something was wrong as you tightened the bolts and basically bent the disk. It shouldn't take much torque on the transmission bolts until the face contacts the bell housing. If it took a lot of torque to pull it up then you may have misaligned the input shaft. Bouncing around the trans to get things aligned isn't going to "spring" your clutch.

[dawicker]

It looked like the free play was about an inch, but I ran it to it limit just to make sure, but it made no difference.

Yeah, the gears grind if I try to put it in gear when it is running.

I didn't have to apply much force to get everything to tighten up; I pretty much was able the hand tighten all the housing bolts, then a turn or so to get them snug. Through the inspection plate I can see the splines appear to be in the clutch disk and the "fingers" are getting depressed maybe an inch or so, so it looks like everything is working as it should except the disk is not releasing. Very puzzling as it all went together very nicely.

Dave Wicker

[Chopper1942]

I am not familiar with the clutch in your vehicle, but with the inspection cover removed, if you can see the disc between the flywheel and pressure plate, have someone depress the clutch and with the trans in neutral,It use a screwdriver to try and rotate the disc. It should rotate easily, if not try and adjust the clutch to have much less free play, and try again. If this doesn't work then you will probably have to remove the trans and clutch. 

On some clutch assemblies, the disc has to be installed in a certain orientation. If the disc has thick hub with anti-vibration springs, the hub must face the pressure plate or the clutch will not release.

[harry s]

I was going to mention the same thing as Larry did about the disc hub and orientation. Another consideration is the disc lining may be too thick. When the clutch pedal is depressed with transmission in neutral you should be able to turn the disc as mentioned or try putting a thin blade putty knife between the disc and flywheel. The thickness of the lining for '37 is .135"-.139" (each side) not sure about your year.     Harry

[V63]

Depending on atmospheric conditions and time... they can rust to the pressure plate.  Ask me how I know!

[PHIL WHYTE CLC 14192]

Depending on atmospheric conditions and time... they can rust to the pressure plate.  Ask me how I know!

I had the same thing happen once and was only able to put it right by removing the transmission.

[LaSalle5019]

Another vote for what Larry mentioned above - disk orientation. That would definitely cause your problem.
Flywheel side


Clutch cover side


You may be able to look up in the inspection hole to see that

[Jay Friedman]

I am not familiar with the clutch in your vehicle, but with the inspection cover removed, if you can see the disc between the flywheel and pressure plate, have someone depress the clutch and with the trans in neutral,It use a screwdriver to try and rotate the disc. It should rotate easily, if not try and adjust the clutch to have much less free play, and try again. If this doesn't work then you will probably have to remove the trans and clutch..... 

According to my 1935-55 parts manual, in 1936 a Long Mfg. Co. clutch assembly was used.  (The clutch in LaSalle5019 photos is a Long.)  In my experience this problem happens sometimes with these clutches and I've had it happen not only with a Cadillac (specifically a '40 Lasalle hearse) but also with a 1949 Ford (which uses the same type clutch).  What I think happens is that the driven disc gets somehow stuck to the flywheel or pressure plate.  Maybe by moisture or maybe by something else.  Who knows? 

If you try what Chopper1942 suggests above with a screwdriver and it doesn't work, I remember with the LaSalle and the Ford trying something else which worked.  Now this was decades ago so my aged memory might be faulty, but here goes.  Put it in 1st gear before starting the motor.  Now on a quiet road or an open area like a parking lot start the motor with it in gear.  The car should lurch forward and start to run slowly. Get it up to about 15-20 mph and with your right foot on the gas pedal at the same time step hard on the brake pedal.  This may force the driven disc to become unstuck.  I know it sounds nutty, but before having to remove the transmission it might be worth a try, and as I remember it sometimes worked. 

I remember another method that worked with Fords from my long lost 1950s adolescence.  This is done with the car parked.  Put the transmission in 3rd gear.  Release the hand brake.  Now bounce up and down on the front bumper, at the same time try to push the car a bit backwards.  It might be best with an assistant helping.  I remember we'd eventually hear a click, signifying the clutch was now unstuck.  Again, it's a bit nutty, but why not.  As mentioned above, it sure beats taking out the transmission and clutch.

[Chopper1942]

I've done what Jay suggests on new medium trucks with dual disc clutches that had sat on the lot for extended amount of time. But, you need to keep the clutch pedal down so the pressure plate is released and when you stomp on the brakes the disc can be popped off the flywheel. I have a rod that I use to hold the brake pedal down and locks to the seat when doing doing alignments. I used it on the clutch pedal so I could operate the gas and brake. Sometimes you have to do this proceedure several times before it breaks loose.

[Jay Friedman]

Chopper1942 is right. 

In the first method I mentioned, we must have used a rod on the clutch.  (Or maybe there were 2 guys: one who worked the brake and clutch pedals and a second guy who sat next to him on the seat and worked the gas pedal.) I can't remember exactly, but how else could the driven disc become unstuck? 

In the second method I mentioned with the Ford back in the '50s, we must have had another kid who sat in the car and stepped on the clutch pedal. 

[TJ Hopland]

How hard is it to get the trans out of this thing?  Seems like there are a lot of unknowns including the possibility that there are missmatched parts or improper assembly.  Trying to force things may just make it worse.  Unless you know it got wet?

I guess another question is how expensive or hard to find are all the parts?  IF its easy and you have a pile of parts I guess just try and force it but if you could risk damaging hard to find stuff I would think it would thing the best bet would be to take it apart and see whats going on. 

I don't do a ton with manuals but the ones I have dealt with are pretty easy to remove.  There tends to be space around them to access bolts and they are not that large or heavy.   

[LaSalle5019]

How hard is it to get the trans out of this thing?  Seems like there are a lot of unknowns including the possibility that there are missmatched parts or improper assembly.  Trying to force things may just make it worse.  Unless you know it got wet?

I guess another question is how expensive or hard to find are all the parts?  IF its easy and you have a pile of parts I guess just try and force it but if you could risk damaging hard to find stuff I would think it would thing the best bet would be to take it apart and see whats going on. 

I don't do a ton with manuals but the ones I have dealt with are pretty easy to remove.  There tends to be space around them to access bolts and they are not that large or heavy.   

Not sure about the 1936 but my 1939, with the X frame, is a bit of a pain to pull the trans as you have to get the long extension housing pulled back through a hole in the frame but parts are not too hard to find.

[Chopper1942]

If the humidity is high where the vehicle is located and it is not driven for an extended time, the clutch disc will absorb the moisture from the air and the metallic strands in the woven disc material will rust/bond to the flywheel and/or pressure plate. 

I would try taking out all the free play, depressing the clutch with a prop of some sort, trans in neutral, and rotate the disc with a screwdriver. If it won't rotate, take a putty knife and try sliding it between the flywheel and disc and pressure plate and disc. If it's sticking, you may be able to free it up.

Then try the drive and jam on the brakes method.

If you have to pull the trans, get some synthetic brake grease and before you reinstall the clutch, (lube with a thin film of grease), the inside of the pilot bushing, the end of the trans input shaft, the splines on the input shaft, the front trans bearing retainer where the throw out bearing rides, and the groove for the clutch fork. Pack the groove on the inside of the T/O bearing if it has one.

Make sure the disc is properly oriented. Get a plastic disc aligning tool to make sure the disc is aligned. Tighten the pressure plate bolts 1 turn at a time in a criss-cross pattern. This will prevent bending/distorting the pressure plate.

When you go to install the trans, put it in gear and rotate the output shaft to align the splines and wiggle the trans until it slides in place. Don't force it. If there is clearance, cut the heads off a couple of bolts, cut a slot in the cut off end and install them in the bellhousing. This makes it much easier to align and takes the weight off while installing the trans.

Hope this is some help.

[Jay Friedman]

Chopper, Great advice.  One word of caution, though. I would be hesitant to put a film of grease on the splines on the input shaft of the transmission. Wouldn't there be the danger of that grease, even a small bit, getting thrown onto the driven disc by the shaft's rotation?  I've had that happen on my '49, which caused awful clutch chatter.  I ended up having to pull out the trans and clutch all over again to replace the driven disc.

I agree with LaSalle5019.  The 37 and later manual transmission is long, so is hard to manipulate in and out.  It also weighs almost 100 pounds.  I find you need 2 guys to do it, one on each side, even with a good transmission jack.  The 36 transmission is different, but I've never worked on a '36 so don't know what the differences are.

[harvey b]

I had a farm tractor one time that the disc rusted to the flywheel,i had to statr it in gear to move it.I was jocjeying it around the yard to move it into the shop to "break" it apart to loosen up the clutch,i put it in reverse and backed up and it broke loose?  maybe try and rock it in gear with your foot on the clutch,it might jar loose that way,have some one push the car back and forth,Im pretty sure the disc cant be installed backwards,just no room for it to fit that way.Was this setup on the motor when you got it or did you install it recently?. harveyb

[harry s]

One other thing I learned the hard way is to check the fit on the pilot bearing before installing the transmission.     Harry

[Chopper1942]

I have never had an issue in over 50 years of installing clutches.

I guess I need to explain my "thin film" of grease. I use an acid brush, put some synthetic brake grease on the brush, wipe the brush off, and then wipe a thin film on the splines. The splines will look wet. There should not be any gobs of grease on the splines. I do the same with the splines of the clutch disc hub. This keeps the disc from sticking to the input shaft and slide easily when released and applied.

Also, these old clutch discs contain asbestos so wear some nitrile gloves and make sure the gloves are clean when you handle the disc. Don't use compressed air to clean any parts inside the bellhousing. Get some BrakeKleen and use it to wash off the parts. Do this over a drain pan and then wipe out the drain pan and dispose of the paper towels,

[dawicker]

I got sidetracked with other projects, but I was able to free the clutch using a slightly modified version of the technique mentioned by Jay. Instead of taking the car on the road, which would have required towing it up a hill out of the shop, instead I put it in 3rd gear, released the hand brake, and locked the clutch pedal down using a couple of hand squeeze clamps on the steering column, which blocked the clutch pedal. I then hooked my 4WD to the rear and gave it a couple of quick tugs. The cluch broke free on the second tug. I want to thank everyone who contributed with the "stuck clutch" experiences that set me on the right track. It seemed the logical problem despite the fact that the clutch worked on the engine before it was transplanted and the engine sat in an enclosed trailer for only a couple of months and never got wet! However we did have continuous high humidity (>90%), so that is a good reason to store these beasts in a low humidity environment. I put a dehumidifier in my recently constructed shop to keep the humidity down, not for this specific reason, but now I am convinced it was a good idea.

[Jay Friedman]

........I then hooked my 4WD to the rear and gave it a couple of quick tugs. The cluch broke free on the second tug....

Sometimes with an old Cadillac (and its clutch) you just have to show it who the boss is!