Clutch Problem - Need advice

[johnbartlett19]

Hi folks. 49 Farmall Cub, I believe I have a Rockford clutch based on the pictures in the parts catalog.

I took her out for a short mow yesterday using the Woods brush hog. Clutch has been a bit soft and not returning well. Then as I pulled up in front of the garage, the clutch would not disengage. Had to shut off the engine and start her in reverse to get her in the garage.

This morning I pulled off the access port and a 5/16-18 3/4" hex head bolt fell out. It is badly worn on one side and mangled on the other side.

I have not been into the clutch before so I am not an expert here. The throw-out bearing moves with the clutch pedal, but is too far back to engage the arms when the clutch pedal is down. I can adjust, but still trying to understand 1) why did it stop working all at once, and 2) where does that bolt belong? I have searched through the parts manual photos and can't find a bolt of that description anywhere in the clutch.

Any hints on where to look next? Appreciate any advice. Thanks! JB

[Jim Becker]

The only similar bolt I can think of is the one that holds the 2 halves of the yoke together. Loosing it can cause the symptoms you describe. However, I believe it is a 1/4-inch bolt. Someone may have put in a larger bolt. You can see the bolt I am referring to on this page at TM.
http://www.tmtractor.com/new/cl/112fp.htm
If that is your problem, the bolt can be replaced through the hand hole.

[Eugene]

Also check to see if you are missing a bolt holding the pressure plate to the flywheel.

[Dale Finch]

This would not have anything to do with the bolt you found, but make sure the pedal free play adjustment bolt (if you have one, it's at the base of the clutch pedal) is tight.

IF someone turns the engine manually while you look through the hand hole, you should be able to see if the clutch has all its parts.

And as Jim mentioned, the bolt holding the yoke can come loose... we found one missing on a Cub at DSCF.

[Glen]

Hi,
There are 6 bolts about like the 1 you described that hold the pressure plate onto the flywheel.
I would look and see if 1 or more fell out, and possibly the others could be loose.
Possibly someone put in bolts that are too short.
It doesn't say the length of them in the Cub parts manual.

Below is a page from the 1949 Cub operator's manual, showing the clutch in the bottom pic.
It is not complicated. It explains adjusting the pedal free play on the page.
The free play is measured at the surface where you put your foot.

http://farmallcub.com/rudi_cub/www.clea ... age-40.jpg

You will need to turn the engine to 3 different positions to check the bolts.
Use a good light to see in the hand hole.
It is helpful to have the Cub in a building, so you don't have to look up at the bright sky.
The bolts should all have lock washers.
If they are loose, tighten them evenly going around the pressure plate, it loads the springs as you tighten the bolts.

Grease the throwout bearing grease fitting with cheap grease while you are there, they are sometimes dry from no lube. They say on here to use cheap grease so the oil in the grease will absorb into the graphite material.
The graphite material sticks out of a new throwout bearing 5/16". Sometimes they wear down from use.

Below is a pic from TM Tractor of the pressure plate and the bolts that hold it on the flywheel.

[johnbartlett19]

Hey thanks for all the replies on this. I decided upon inspection that I should split the tractor and change out the clutch, as the clutch fingers and the throughout bearing were both quite worn. I now have the tractor split and am attempting to replace the rear seal since I have the tractor apart. See separate question about which direction the seal gets installed. Then I will start putting her all back together again.

My clutch rod doesn't want to turn to make an adjustment, and the threaded part appears to be back by the pedal, inside the tunnel. I have not yet tried to reach back there and pull out the pin to get the whole rod out and see what can be done.

I had a stripped bolt on the bottom left of the seal retainer, and thus no bolt in that position holding up the oil pan into the retainer. This could have been the source of some of my oil leak. Today I drilled it out and put in a helicoil, so I have that under control. Now off to the store to get some gasket sealer so I can put the retainer back on.

Again thanks for the help!

[Glen]

Hi,
Are you sure your Cub is a 1949, the only Cubs with a threaded rod for the clutch adjustment, inside the housing were 1947- mid 1948.
IH changed the adjustment method at serial number 32229, the Cub parts manual says.

Below is a page from the 1947 Cub operator's manual, showing the clutch, and the rod.
The end with the threads goes to the front.

http://farmallcub.com/rudi_cub/www.clea ... age-40.jpg

Below is a page from the 1949 Cub operator's manual, showing the clutch, and the rod.
The newer style rod has no threads, it has 2 solid ends on the rod.

http://farmallcub.com/rudi_cub/www.clea ... age-40.jpg

Here is some info for replacing the clutch, maybe you knew it already.

Check the throwout bearing holder for wear in the holes, and the long pin at the top of it for wear, the holder should be solid side to side, so the bearing is held centered on the pressure plate fingers. It should move freely forward and back.
The holders are different for the 2 styles of adjustments.
TM Tractor has a new holder for the 2nd style of adjustment, and a new pin.

Check the finger height on the new pressure plate after assembling it on the flywheel.
They have said on here that new pressure plates often come set wrong for a Cub.
They should be set to 1 3/16 - 1 1/4" high, they have said on here.
Below is a pic of where to measure, the plate has to be assembled on the flywheel, not off, like the pic is.
The 3 fingers should form a flat surface for the throwout bearing to push on.

They recommend on here to soak the new throwout bearing in light motor oil for a day before putting it in.
Then grease the grease fitting with cheap grease, so the oil in the grease absorbs into the graphite.

The longer side of the clutch disc splines goes to the rear.

Tighten the 6 bolts holding the pressure plate onto the flywheel gradually, or equally, it is loading the springs as you tighten the bolts.

I don't know if you replaced the pilot bushing, some of the new bushings are too small an ID when driven into the crankshaft hole.
The running clearance needs checking before putting the pressure plate on, and the bushing needs reaming if too small.
The Cub service manual gives the running clearance, and the size the end of the clutch shaft should be.
One of the experts on here has said that some of the pilot bushings are still good, and don't need replacing.
Grease in the bushing, and the end of the shaft, before putting the Cub together.

Check to see if the clutch shaft is straight, turn it while the Cub is split and be sure it is straight.
People have said on here that they have found bent shafts.