Clutch linkage problems on 48 DeSoto

[MarcDeSoto]

I'm having some trouble with my clutch linkage.  I adjusted my overcenter spring using tool C705.  And I adjusted the clutch fork to have one inch free play, but the clutch doesn't return after being applied.  see video below

 

 

[MarcDeSoto]

I solved the excessive play on the pedal shaft just by hammering the shaft in a little bit.  But the kink that stops the return of the clutch pedal has me stumped.  

[Sniper]

You are missing a washer between the pedal and the master cylinder.  The parts manual shows it.

 

The spring you are calling a clutch return spring, isn't one.  It's to take the slop put of that part of the linkage and retract the release bearing.

 

 

 

Edited August 11, 2022 by Sniper

[MarcDeSoto]

I don't understand your statement.  I checked and I do have a washer between the clutch pedal and the MC.  I took the fork rod and clutch release pull-back spring off.  I did this because it seems the clutch release bearing is extremely tight.  Is it supposed to be this tight?  If not, I guess I have to pull the drive shaft and transmission to investigate.  

 

 

 

 

[chris 48 P15]

the same thing happened to me 

the clutch pressure plate spring are heavy not able to push clutch fork by hand that looks ok to me not saying throw out bearing is correct or not

the leverage created with pedal is why we can compress the pressure plate springs

at the clutch fork for my p-15 it says to have a 1/8-to-5/32-inch free play at clutch fork should give the one-inch free play at pedal

the clutch return spring looks right to me should have tension when installed

once it is all together you need to make all adjustments then and the pedal will bounce back into place

you may need to adjust all linkages 

btw i learned some new things with the water pump thread who knew water pump grease

[MarcDeSoto]

I'm wondering if I have the right clutch fork pull back spring.  It is 7 3/4" long.  Sound and look right?  see vid.

 

 

[MarcDeSoto]

Has anyone tried to use tool C705 to set the overcenter spring to its correct alignment?   It is for putting the adjustment on the overcenter spring.  I can't seem to get all three points to align.  

[MarcDeSoto]

After stepping on the clutch pedal with the clutch fork rod connected, it pushes the clutch fork in a normal manner, so I don't think that is the problem.  I'm still stumped at what is causing the clutch pedal to stay down after being pushed down.  I noticed that this condition improves if I tighten up the clutch fork rod so that there is no pedal free play, but you are supposed to an inch of free play.  What should I do now?  Thanks.

[MarcDeSoto]

On 8/10/2022 at 5:21 PM, MarcDeSoto said:

I solved the excessive play on the pedal shaft just by hammering the shaft in a little bit.  But the kink that stops the return of the clutch pedal has me stumped.  

No I didn't.  The excessive side play came back.  I guess I need to put an extra washer in there to take up the slack.  

[chris 48 P15]

tool c-705

the holes should fit into linkage and adjusting the turnbuckle will bring the back end up or down

when adjusted properly all three points should line up into tool 

i made this tool from schematics on this website 

i will send a picture of clutch fork pull back spring on my car tomorrow for comparison

the car is 1948 Plymouth club coupe 

did it work properly before taken apart 

maybe needs certain amount of pressure or spring tension to work 

the parts book doesn't list specific size for spring

[Kilgore47]

Check the end of your clutch fork rod.  It may be worn.  I had the same problem of the pedal not returning to the top.  One picture below shows the rod and pin with excessive wear.  The other picture shows that I was able to weld and repair both the rod and the pin.  With the repairs made the clutch pedal returns to the top every time now.  Check other areas for wear also.

[keithb7]

My suggestion is to study the linkage system to understand how its supposed to work. What pulls the pedal back? If it can’t come back what’s hindering it from returning? Take photos of the assembly before you take it apart. Look for heavy linkage use and wear as indicated above.

 
Sometimes partial reassembly helps find the root cause. Get the linkage cycling and returning, maybe with partial parts installed. Keep adding parts and cycling the pedal. Once it binds up you have ID’d the part causing the problem.
 

Understanding how it works is key to troubleshooting and fixing it.  Not sure if that helps, but is what I do when I get stuck. 

[chris 48 P15]

here are the spring pictures 

[MarcDeSoto]

I took the clutch torque shaft off with the clutch fork rod.  The fork rod has a slight bend in it, so I will try to straighten it.  Also the clevis pins have lots of play in them, which I will try to fix with more washers.  You have to be careful with that overcenter spring.  It has a lot of pent up power!  

[MarcDeSoto]

I straightened the fork rod and disassembled the clutch linkage and re-assembled it.  I got it so the clutch pedal now does return, but the overcenter spring gauge does not line up.  I'm thinking I put the turnbuckle on in an incorrect manner.  When I turn it, it gets close to coming off of the right side, so still more work to do.  

 

 

[MarcDeSoto]

James replied to my questions, but I thought I should share it here.

 

Hi Marc,

 

Just got back into SF.  Have you run through all the procedures as outlined on Page 25-26-27 here:

 

https://www.web.imperialclub.info/Repair/Lit/Master/016/Page26.htm

 

One thing to note. If you have one inch of travel on the pedal but do NOT have the 5/32 inch clearance between the end of the rod and the clutch arm then something is bent.

 

One thing is to never use the over center spring to try and adjust the clutch. Never.

 

I have had BAD luck in the last 10 years with clutch's. The re-builder's are not watching the detail on the arm height, the correct springs nor the marcel (the wave spring) on the units.

 

On my 1949, I know something is wrong as I had to build a linkage arm an inch longer as the stock one was too short and I did not want to pull the entire thing apart again. I will at some point...

 

If you have one inch of play, 5/32 clearance and the spring is adjusted using the tool;  then I would say that either something is bent, the throw out bearing arm is wrong, the throw out bearing housing is wrong or the arms on the clutch arms not adjusted to the correct height.

 

James

 

[keithb7]

Maybe it's an optical illusion but is the rod that threads into the turnbuckle bent slightly?

It looks little skewed off straight too. Could it be that it is supposed to mount on the other side if the pin?  As per the image below.

 

I looked in my '53 parts book. It's another different design again by then. I look in my '49 parts book. Seems different too. No turn buckle shown. 

 

 

Edited August 13, 2022 by keithb7

[keithb7]

I found this illustration in another parts book. It utilizes a turnbuckle. Looks pretty different than yours  Unsure if it is of any use for you. Thought I post it anyway.
 

 

Edited August 13, 2022 by keithb7

[chris 48 P15]

the question about the tool not fitting

i believe means it is out of adjustment

turning the turn buckle will move the pins or the base of the tool to sit on frame 

when everything lines up it is adjusted properly

readjust the clutch free play after

 

[MarcDeSoto]

Keith, the clutch pedal rod is correctly put on the inside of the torque shaft.  The pedal rods are slightly bent to fit better.  But I noticed another problem I'm having.  The Master Tech filmstrip says you must have 5/32" free play at the clutch fork. You check it by removing the pull back spring and jiggling the fork so that it has 5/32" free play at the fork rod, which produces 1" free play at the pedal.  But when I disconnect the spring there is no free play at the fork.  When I try to screw the fork rod nut back to make the fork rod shorter, it WON'T turn anymore, even though there is more thread there.  I can't think of why the fork rod nut stops unless the rod has a messed up thread.  

 

BY THE WAY, 5/32" FREE-PLAY AT THE FORK IS JUST A HAIR MORE THAT 1/8".  REMEMBER YOU HAVE TO DISCONNECT THE PULL BACK SPRING TO CHECK THE PEDAL FREE-PLAY!

 

Edited August 14, 2022 by MarcDeSoto

[MarcDeSoto]

Well, I finally got the clutch rod unscrewed from the clutch long nut that goes into the fork.  Luckily, my Tap and Die set had the needed 3/8" 24 thread tap and die.  I could see that the clutch rod threads had been stressed and were dry.  I lubed them and tapped and died the threads.  Now they screw together easily!  I guess I'm becoming a junior master mechanic bit by bit.  I have had this clutch linkage assembly apart so many times now, I think I'm beginning to understand it!  

 

 

[MarcDeSoto]

17 hours ago, keithb7 said:

I looked in my '53 parts book. It's another different design again by then. I look in my '49 parts book. Seems different too. No turn buckle shown. 

Keith, yes, looks like 1948 was the last of the turnbuckle design.  The 49 S-13 DeSotos eliminated the turnbuckle, but still had an overcenter spring.  It was adjusted by turning the eyebolt at the front of the spring to align with gauge C-853 on the overcenter spring.  Looks to be a simpler design.  What do guys do who don't have these special Miller tools?  

 

Edited August 14, 2022 by MarcDeSoto

[kencombs]

5 hours ago, MarcDeSoto said:

  What do guys do who don't have these special Miller tools?  

 

Can't speak for everyone, but trial and error works.   Eventually.  Adjust, check feel, redo, over and over and over.

[MarcDeSoto]

Speaking of trial and error, I had to learn the hard way that there is just one way to mount the heavy overcenter spring on the clutch torque shaft.  After hooking everything up except the spring and the clutch fork rod, you must hook up the overcenter spring, then unscrew the clutch fork rod nut so that it is at its shortest length.  Then, with force, pull back the clutch pedal and hold it with all your might.  Then have a strong friend pull back the clutch fork enough to slide the clutch fork rod into the fork.  I've tried all the other ways, but this seems to be the only way that works.

[Cannuck]

Kieth I got under my car and had a look see.  Marks is hooked up properly and my turnbuckle is also bent like Marks .