Looking for 1958 CASE 400 PTO clutch replace/repair advice

After a lot of repair work this past summer/fall/ winter, I finally got to do some much needed field mowing weeds with the rotary mower on the back of my 1958 CASE 400 diesel tractor. The PTO clutch was slipping badly when I got the tractor years ago. It is slipping MUCH worse now.

I don't have the forked PTO adjuster tool and was not able to figure out how to prevent the clutch from spinning when I tried to adjust it. I have not taken the clutch out either.

I probably need new parts (friction discs, plates and spacers) but was hoping to try an adjustment before doing anything else. The PTO clutch has a LOT of drag on it when disengaged. I can barely keep the shaft from turning whenever the engine is running.

Can the clutch PTO be adjusted or removed without the special forked clutch tool ? Does anyone know where the tool can be bought ? I was not able to find any listings for it.

There is NO servicing or adjusting that requires that tool specifically, many Case owner have never seen one, the tool is for adjusting only , has no part in assembly or disassembly and many of us simply use screwdrivers in most applications, If you desire a tool tale a piece of 5/16 rod stock, pound the end flat and make a slot 1/4 inch deep in the end of it wide enough to slip under the head of the adjusting pin. pound the end fairly thin and shape it and grind or file the notch in it, it will be helpful on a 400.

(quoted from post at 15:05:45 09/10/20) 1958 CASE 400 diesel tractor..

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CORRECTION : It's a 1956 large frame round nose CASE400. My mistake.


After reading suggestions and other descriptions of the PTO I decided i would take mine out to have a look. The hydraulic pump is not there. This 400 has been modified with a piece of diamond plate covering the hole. A different pump now runs off the front of the crankshaft.

Does anybody know if the PTO clutch can be pulled out with the lower shift rod and lever in place ? I'm wondering if the missing hydraulic pump makes that possible on this one.

Also is it one gasket for both pump and pto ? Are there new gaskets available ?

It's the early version of the 400 with the round plug to reach the clutch pin for adjusting it. I can't turn the PTO by hand after pulling out the lock pin. It won't adjust. it's stuck!

I believe that tractor has 2 lock pins, one will be short and the other long the short one needs to be pulled out, the shaft turned till the other one snaps in, repeat till you get the proper snap in feel. That plate on top is easy to remove and you can get a good look at the setup, the engagement shaft must be removed to get the fork out of the way that engages it. It is not normal for the adjusting ring to be seized but I guess anything is possible. I guess if I were you I would have that diamond plate cover off in a minute to see whats goin on. The hydraulic system would have to come off to remove the assembly so you are ahead of the game

I was able to get the PTO clutch adjusted. I used and old screwdriver and ground a notch into the flat blade/end. Used that to hold the pin out and inserted a thinner screwdriver aimed down though the plug hole to prevent the PTO clutch from rotating.

The spline turned easily by hand and I could hear the other pin click into the slot. It wasn't easy to keep both screwdrivers in the right spot but i managed. Got a little better at it by the time I was done. Rough guess was I got it about 8-10 clicks tighter. It was VERY much out of adjustment apparently.

The hand operated control lever end moved about 8" before getting to the point where all the free-play was taken up by the clutch release collar. Now it moves only about 1/2" before that point and requires a lot more force on the lever to pull it over-the-knee and engage the PTO.

The spline still moves easily when the clutch is not engaged. I'm guessing I have no warped plates or discs at this point. What I do have is opaque and coffee colored oil in there. I'll be changing that today and hope to give the brush hog another run later on.

Can't wait to see if it goes through the deep weed cover without the blades constantly stopping. The cutting sure would go faster if it does.

Drained out the coffee-and-cream colored oil, Rinsed it with about a quart of gasoline then about a half gallon of new hydraulic transmission oil. Filled it up.

Got another couple of clicks on the PTO clutch adjuster pins. When readjusting the control lever, I discovered the pinch bolt on the upper release shaft lever needed to be tightened ! Tightened it and finished making the adjustments to give me what feels like 50 lbs or less.

I noticed the PTO shaft moves in/out slightly as I move the operating lever. Kept adjusting the clutch until it was barely any movement. I'm still somewhat confused about the 50 lb measurement. Seems like it depends on how long the rod is from the operating lever to the upper release shaft lever. Not on how much freeplay there is with the clutch collar.

It does not slip now when going through heavy weed growth and some sizeable brush/saplings so I'm happy but confused. My worry is it's too tight now and the clutch bearing will wear out on me. That's why I set the amount of pull to less than 50 pounds, maybe. Did it by adjusting the length of the rod though.

(quoted from post at 11:08:17 09/14/20) Now I am confused, I m looking at my 400 service manual,
what rod are you speaking of?CM

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Chuck,
The rod is P/N A7443. Attaches to the hand operated lever for the PTO.

(quoted from post at 12:32:49 09/14/20) Do you have the small 400b or large round nose 400?

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jon f,
It's a 1956 large frame round nose Racine built 400 diesel with a standard front axle.

I finally realized the over center is action is on the clutch itself. In the photograph I marked the over center pivot. I mistakingly adjusted it too tight. It could not go over center.

I backed off the adjustment a little at a time. Kept trying and finally got it loose enough to pop over center. I don't think it ever did that before. It made a metallic snap when it popped into the engaged position

It wouldn't pop back out over center. It was stuck in the engaged position. The grade 2 pinch bolt in the upper throw lever was stretched. The keyway for it in the upper throw out shaft has a lot of wear.

I put in a new grade 5 pinch bolt. Now I can get the PTO clutch to pop into the engaged position and back out to the disengaged position. Hope it lasts.

Final adjustment was the length of the top throw out rod. I got the PTO hand control lever to go over center close to the same as when the clutch pops over center. I was confused by the two different over center pivots.

I had no idea it was supposed to pop when you engaged the PTO. And pop back out when you disengaged it. Total over center newbie here. Thank you for teaching me, everyone.

(quoted from post at 01:45:52 09/15/20) I finally realized the over center is action is on the clutch itself. In the photograph I marked the over center pivot. I mistakingly adjusted it too tight. It could not go over center.

I backed off the adjustment a little at a time. Kept trying and finally got it loose enough to pop over center. I don't think it ever did that before. It made a metallic snap when it popped into the engaged position

It wouldn't pop back out over center. It was stuck in the engaged position. The grade 2 pinch bolt in the upper throw lever was stretched. The keyway for it in the upper throw out shaft has a lot of wear.

I put in a new grade 5 pinch bolt. Now I can get the PTO clutch to pop into the engaged position and back out to the disengaged position. Hope it lasts.

Final adjustment was the length of the top throw out rod. I got the PTO hand control lever to go over center close to the same as when the clutch pops over center. I was confused by the two different over center pivots.

I had no idea it was supposed to pop when you engaged the PTO. And pop back out when you disengaged it. Total over center newbie here. Thank you for teaching me, everyone.

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That bolt is not factory nor is that long pin on the other end of same links. Check pic 1, see how tight those pins and links are, that is factory. You don't want that kind of slack there as the engagement force can cant the links and possible break the ends of the links similar to the link in the 2nd pic.

I would be very leery of putting a grade 5 bolt there with all that slack, better to bent/break an ungraded or grade 2 bolt than one of those links which would probably be very difficult to find. Better yet eliminate the slack problem. IIRC those pins in some of the clutches had shoulders for the larger holes in some links but that may not be true in all designs especially older ones.

These pics are from someone here, either pto of propulsion hand clutch don't remember which.

Joe

Joe,

I didn't make it very clear did I ?

The bolt I replaced is a pinch bolt that holds a lever to the end of the upper cross-shaft. It's an exterior pinch bolt. Outside the housing up on top, under the seat. I did not replace anything inside on the throwout assembly.

I borrowed the photograph I posted from eBay. I did not take my PTO out. All the work I've done inside adjusting the PTO is through the round hole.

The only other adjustment I have done is outside on top. Setting the length of the rod from the operating lever to the lever with the new grade 5 pinch bolt.

Sorry for the confusion.

The pinch bolt didn't hold after a couple of short/long pin clicks. The PTO made the snap sound when the clutch engaged. When I tired to take the PTO clutch out of engagement, the pinch bolt wasn't strong enough. The lever moved on the upper cross-shaft. The PTO lever was all the way forward and down. The PTO clutch wasn't pushed hard enough to disengage.

I took off the lever and upper cross-shaft. Had a close look and realized the woodruff key was not thick enough. I couldn't get the right size locally, today. Got one a little too big and ground/filed it down to fit.

The PTO goes in and out now. Even after 2 MORE short/long pin clicks. Tomorrow, I'll do what I can to measure the force. Thinking of a pulley with a 50 pound weight. I'm probably close to that now.

Update from about 2 years ago ...

The PTO would not slip the way I had it adjusted. The Brush hog was beating itself to death whenever I found another one of the prize winning rocks which there are many in the fields I am trying to maintain. All the welding and repair work I did to the brush hog has been undone already.

When I adjusted the PTO it seemed it would slip too much or it would not slip at all.

I finally took the PTO out. I discovered missing link pairs as in one of the photos above.Two of the pairs of links are missing as well as the pins at each end of the links. Fished out about 1/3 of the pieces from the bottom of the cavity with a magnet.

Apparently the pto had been previously installed with less than all of the links and pins intact. The remaining link pair has double nutted bolts at each end instead of the normal pins and circlips or cotter pins. A used replacement PTO with all 3 link pairs is on it's way and I feel lucky that I was able to find one right away.

The two missing links meant the clutch would only be engaged via one link pair and when disengaged was not being pulled away squarely. Seemed to be causing extra drag when released. Also not engaged tight enough to cut heavy growth without slipping too much unless it was adjusted so tight it was effectively locked up.

One big rock caught the blades so bad it stalled the diesel engine. That's when I knew I had to do something about the PTO. More than just trying to adjust it again.

I am wondering if the pins or the link pairs break very often. Should I put in double nutted bolts through the link pairs instead of leaving the stock links and cotter pins in place when I get the replacement used pto ?

I'll post some photos when I get the replacement pto and am putting it in. Hopefully within a week. For now now I plugged the pto back in to close the hole up.

The replacement pto is in but I have not yet tested it with any mowing. Should be ok although there is still enough drag to rotate the rotary mower blade when disengaged and the mower deck lifted up out of the vegetation. I can easily turn the pto output shaft by hand with the engine off and pto disengaged.

Now I know what it is supposed to feel like when I engage/disengage the pto. It makes a very distinct metallic snap sound just as described in the repair manual. It is much easier to adjust now also since I can really tell when is engaging or disengaging.

The replacement pto is all as expected so I did not bother to post a photo of it. The old one however is a different story. I was able to fish out some of the linkage pieces from the bottom of the case. Not everything missing was in the bottom of the case it seems.

With the old pto out in the daylight it was easy to spot what was wrong. Only one pair of links was still in place and those were held by bolts !!! I am wondering is using bolts on the replacement pto would be a good idea or if it would not help ensure this does not happen again.