clutch

4x4M38 · Posted: Sat Dec 27, 2014 6:19 pm Post subject: clutch

I left Bretto a long and drawn out message on the same subject, but after searching through 7 pages of clutch questions here I realized I needed more info.

How do I determine clutch pedal free play? I removed the clutch inspection cover on top, and watched the throwout bearing while depressing the pedal. I am assuming free play is from the time the pedal is depressed until the bearing comes into contact with the three fingers. It will move prior, just does not touch anything. In a perfect world.

From the pedal at top, to when the bearing touches something inside the clutch was over 2-1/2" inches. It moved the bearing a little, but would not release the clutch.

I got under it, and my cable is threaded all the way into the clevis. There is no more adjustment there if I need to take up slack in the cable.

On the other side I do not have the rod bent at both ends. I have the rod with two clevis' on it. There was plenty of thread on the shaft end left there so I adjusted the free travel on that side. Am I wrong to assume that I can adjust it there versus the other side?

Anyway, now there is about 1-1/4" of pedal travel before the bearing comes into contact with the fingers. The clutch still does not release. I am able to start it in neutral/low, and slowly pull the gear shift into 1st, and it will drive. I could not do that before as I had the transfer in high and it stalled the motor.

I believe the cross shaft is aligned correctly.

I keep reading in the previous posts of clutches being stuck. How do I determine that being a possibility or something else?

Thanks Guys.
_________________
Brian
1950 M38
MC11481
http://www.willysmjeeps.com/v2/modules.php?set_albumName=album372&op=modload&name=gallery&file=index&include=view_album.php

capescw · Posted: Sat Dec 27, 2014 6:42 pm Post subject: Possible problem solution

On the M38, at least, the most common problem seems to be improper assembly of the cross-arm! The long arm belongs on the clutch side, the shorter arm on the pedal side.
_________________
"Frugality keeps me in the Game"
1952 M38 Project "Lazarus"
1951(?) M100 Trailer
1956-60 USAF Special Weapons Program
http://www.bill-capes.com/insanity - Updated 04/26/14

4x4M38 · Posted: Sat Dec 27, 2014 9:20 pm Post subject:

I will double check in the morning.
_________________
Brian
1950 M38
MC11481
http://www.willysmjeeps.com/v2/modules.php?set_albumName=album372&op=modload&name=gallery&file=index&include=view_album.php

wesk · Posted: Sun Dec 28, 2014 1:47 am Post subject:

Free play is measured at the pedal and is determined by depressing the pedal with your hand. You measure from full up to the point at which resistance is felt. The pedal will still have a lot more travel to go yet to release the clutch. As it says on page 233 of the M38 operator's manual 1 1/4" free play is correct.

As Bill mentions it is not uncommon for folks to get the cross shaft 180 degrees out. Little arm goes left and long arm goes right.

A truly stuck clutch disc will not release even though you can see the release bearing moving the pressure plate fingers. If this be the case then hook up a tow vehicle and before you start rolling put the tranny in 2nd and then tow the jeep with the pedal released. If she's still stuck then repeat the process but use a tow vehicle with a crash bumper on the back and start the engine then have your tow vehicle slow to a stop while you keep the jeep running in 2nd gear with the pedal in and the jeep tight against the rear bumper of the tow vehicle. If she still doesn't pop loose pull the tranny and the pressure plate.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

4x4M38 · Posted: Sun Dec 28, 2014 10:51 am Post subject:

Thank you for the information Wes. I have 1-1/4" travel before there is resistance. The bearing starts moving right away, but does not offer any resistance until I have pushed the pedal 1-1/4".

How much more should the bearing (and arms) move to release the clutch?

I can see the arms just start to move before the pedal fits the floor.

It is 34 and sleeting. I'll fortify myself and go have a look at that cross shaft.

Thanks again for the clarification.
_________________
Brian
1950 M38
MC11481
http://www.willysmjeeps.com/v2/modules.php?set_albumName=album372&op=modload&name=gallery&file=index&include=view_album.php

wesk · Posted: Sun Dec 28, 2014 2:41 pm Post subject:

4x4M38 · Posted: Sun Dec 28, 2014 4:00 pm Post subject:

Checked the cross shaft.

Left bracket is approx 1-1/2" center of pin to center of shaft.

Right bracket is approx 2" center of pin to center of shaft. Definitely longer than the left side.

Also note. The right side clevis is threaded all the way onto the shaft, and the left side has a clevis as well. There is additional adjustment available on that side.

http://willysmjeeps.com/v2/modules/gallery/albums/album372/both_brackets.jpg

Question. Being two clevises, one on each side, is it possible to have them both out of adjustment somehow and the 1-1/4" free play measurement at the pedal be correct, and the clutch still not release? I.e., is that extra clevis and adjustment screwing with the original geometry?

Now a poor photo through the inspection plate looking straight down at the throwout bearing. Looks like the release arm is worn, and there is quite a gap between it and the bearing.

http://willysmjeeps.com/v2/modules/gallery/albums/album372/Clutch.jpg

How far does the arm have to move?

Tks,
Brian
_________________
Brian
1950 M38
MC11481
http://www.willysmjeeps.com/v2/modules.php?set_albumName=album372&op=modload&name=gallery&file=index&include=view_album.php

4x4M38 · Posted: Sun Dec 28, 2014 4:02 pm Post subject:

Just thinking out loud. Maybe I need to adjust that left shaft to total length of the original OEM rod bent at both ends, then go to the right side and start over.

Right now I have no idea where I am.

Does that make sense?
_________________
Brian
1950 M38
MC11481
http://www.willysmjeeps.com/v2/modules.php?set_albumName=album372&op=modload&name=gallery&file=index&include=view_album.php

wesk · Posted: Mon Dec 29, 2014 1:01 am Post subject:

Those extra clevises on the pedal to cross shaft rod were added to compensate for problems , usually wear, as a shortcut or circumnavigating proper repairs. My M38 is in storage now so we need one of the folks to measure the length of their stock rod so you can get that part of your pedal geometry where it belongs.

_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

4x4M38 · Posted: Mon Dec 29, 2014 7:55 am Post subject:

Hi Wes,
I am thinking correctly? Set that rod length first before anything else?

Tks,
Brian
_________________
Brian
1950 M38
MC11481
http://www.willysmjeeps.com/v2/modules.php?set_albumName=album372&op=modload&name=gallery&file=index&include=view_album.php

RICKG · Member Joined: Aug 31, 2010 Posts: 1740 Location: SO IDAHO

Bretto · Member Joined: Nov 24, 2010 Posts: 1390 Location: Orem, UT

In your clutch picture (hard to see) it looks like you say, the bearing is not touching the finger and it almost looks like a burr is present like it has been worn. Are the other finger like this? Perhaps that release bearing is seized and the fingers were taking on the task of the bearing, wearing them away. You should be able to reach in and spin the bearing by hand, engine off of course.
_________________
Brett
'51 M38
PHOTO DIARY OF MY BUILD

4x4M38 · Posted: Mon Dec 29, 2014 9:35 am Post subject:

There is a burr on the finger. I think it is a result of somebody riding around all day with their foot on the clutch. All day, every day, forever. I suspect the other two are the same. There is wear on the front of the bearing as well if you look closely.

I took off the cover to set the free play. When I depress the clutch pedal the bearing moves forward. Once I take up the 1-1/4" I set the other day, I can hear it click, so it is contacting the fingers, and the pedal becomes more firm. From that point it still moves forward, but apparently not enough to release the bearing. If the fingers are excessively work as is the front of the bearing, it may have to go further from spec, correct?
_________________
Brian
1950 M38
MC11481
http://www.willysmjeeps.com/v2/modules.php?set_albumName=album372&op=modload&name=gallery&file=index&include=view_album.php

4x4M38 · Posted: Mon Dec 29, 2014 10:37 pm Post subject:

In between chilly and nasty weather a sunny and 60's
day provided quite a bit of information.

Began by measuring the double clevis clutch pedal rod on
the left. Almost 10-3/4 inches overall, spot on to the Omix/
Ada bent rod replacement I found on EBay. That was the good
news. Both mounts (tangs) as well as the one on the transfer case side
had worn holes that measured at least 1/16 to 1/8" of slop.
Accumulative wobble has to be bad.

I pulled the inspection plate. Sunshine instead of cloudy weather
provided for better conditions for looking at the release bearing.
I was able to reach in and grab the bearing. It moves back and
forth freely, and wobbles on the shaft, and metal particles
are visible around it. Obviously the bearing is shot and is the major
cause of the clutch not releasing. So a tear down and replacement
is coming.

The second project was hooking up the replacement emergency
brake parts. I had thought of buying a couple of cable end clamps
but made one and bought a cheap one for the upper end.
The one I made worked fine on the transmission end but the
other one would not hold. I will be ordering two replacements
as well as the wire spring extension that hooks to the frame
mount. Lesson learned. For want of a shoe.....

So. Feather day in the words of the old fox, but much info
was obtained, and a lot from board members as usual.

My best wishes for all of you for the New Year.

Brian
_________________
Brian
1950 M38
MC11481
http://www.willysmjeeps.com/v2/modules.php?set_albumName=album372&op=modload&name=gallery&file=index&include=view_album.php


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