Farmall C clutch chatter- Rear main seal?

The 1949 Farmall C that I just bought has a pretty violent chatter when you let off the clutch even when you let off slow..it leaks oil/trans fluid/hydraulic fluid from everywhere you can think of, so I was wondering if maybe oil was leaking out the rear main seal and getting on the clutch disc? It never slips, just chatters bad. If so, how hard is the rear main seal to replace? The tractor is down to the frame/engine for a paint job, so splitting the engine from the chassis is not an issue, but how hard is the seal itself to do? Thanks!!

If the chatter seems violent, I'd sooner suspect the throwout bearing. There's a good chance, if it's the original, that it's of the old graphite block type. One little chip in the edge of it will cause some pretty serious vibration and racket. If that's what you have, I'd suggest changing over (requires bearing and carrier) to the newer more conventional bearing while you have it open.

Hard to tell if you've got an oil-soaked clutch or not without splitting to get to it and take it off. With the clutch off, it's just a short step to take the flywheel off to take a good gander at the rear of the seal, though you should have a good idea before you ever get that far as to how serious any leak there might be.

A few years ago my super C had some chatter when the clutch was engaged. After talking to several people I was advised to replace the flywheel. I found a machine shop that would resurface the flywheel, they only took off .004 of an inch but it eliminated the chatter.

(quoted from post at 20:12:56 09/02/10) A few years ago my super C had some chatter when the clutch was engaged. After talking to several people I was advised to replace the flywheel. I found a machine shop that would resurface the flywheel, they only took off .004 of an inch but it eliminated the chatter.

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I guess I made it sound worse than it is in my post, it's not something I can't work around, but it's annoying enough to where I'd like to fix it. I guess my question is, is it worth the trouble of splitting the tractor and tearing into it, or should I just let it be? How hard is it to do a clutch/flywheel job on one? I've never done one.

Clutch chatter is usually caused by either a bad throw-out bearing or uneven pressure plate fingers. Oil on the clutch usuaaly causes slippage. It would take a very bad leaking engine rear seal to get oil on the clutch. The pressure plate and disk are acually encased in the flywheel. I know, we have ours apart as I speak. I agree with the previous post about the graphite throw-out bearing. Ours disintegrated on us. The problem you will have is locating a carrier for the bearing. Case/IH dealers don't have original equipment carriers. Need to get an after market one. My local Case/IH dealer was able to get me one. While you have the tractor apart I would strongly recommend checking the finger adjustment on the pressure plate. Also check the condition of the disk. Or just replace both of them. And, of course, replace the leaking seals.

Over on the Farmallcub.com website (see below), we have had a discussion going on over the pros and cons of the graphite bearing versus a steel thrust bearing conversion. Some who have tried the conversion on the Cub report having had problems with the steel bearing not holding up. Since I do not know if the C's bearing setup is similar to the Cub's, it may be that any difference would explain why there has been a problem with the Cub conversion. You indicate that a bearing holder is also required for the C conversion. No one has discussed the need for a separate holder with the Cub. The steel bearing for the Cub has two pins, one on each side of the round bearing that fit in the existing holder. Any comments on this issue would be appreciated.
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On the C, the graphite bearing was sort of the standard. IH offered the steel bearing as an option on the SuperC as part of it's Hydra-Creeper package, the use of which required blocking the clutch pedal down, allowing a hydraulic motor to move the tractor.

I'm sorry I'm not familiar enough with Cubs to discuss any similarities or differences. The graphite bearing on the c/sc was basically a truncated cone of a graphite compund molded or cemented into a cast carrier which, in turn, is mounted to the clutch fork with pins much as you describe for the Cub. Its face was shaped to allow the clutch fingers to recess into it.

The replacement steel bearing and its carrier are two separate items. The carrier is a cast piece (essentially the same shape as the cast base of the graphite bearing, but with different dimensions to compensate for the depth along the shaft of the actual bearing), and mounts to the fork in the same way. Where the graphite block would have been, the carrier is machined for a steel bearing to be pressed in.

Thanks for the reply. The Cub graphite bearing sounds a lot like the one you describe. I have attached a URL link to the steel substitute. One comment that has been made as to why the steel bearing on the Cub breaks down is the fact that the bearing carrier swings from a long pin that goes through the top of the bell housing directly above the bearing. As the carrier is pushed by the clutch rod to and away from the fingers, the bearing would swing through a slight curve as a pendulum swinging. The thought is that the steel bearing may not not be able to accommodate this situation as well as the graphite bearing. I have a Cub and am interested in the conversion since it is the more conventional way to go if I can figure out why there have been problems with the steel bearing. Any additional comments appreciated. Thanks.
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That would probably depend on the geometry of the arc of the line of travel, the "swing" of the fork you refer to. Again, I'm speculating, not being familiar with the differences between the Cub and the A/B/C line.

My notion of the graphite bearing is that is was designed to hold up for a reasonable length of time, but the expectation would be that the friction against the clutch fingers would erode it over time. Thus, and because that wear would have been very gradual, it would have been designed such that it had a length that allowed it to meet the fingers properly when new, and wouldn't be considered worn out (absent any chipping/breakage) until it was worn down to a nub beyond which the casting couldn't swivel in the fork enough to allow it to meet the fingers properly. I don't know how much wear they allowed for in designing for the service life of the bearing, but it seems to me that when new it would work, when worn out it wouldn't, and somewhere in between was an optimum length between the axis of the mounting pins and the bearing face of the graphite. As it eroded, you would have adjusted your clutch linkage to accommodate for the wear.

I'm not an engineer, but I should think that those at IH setting out the specs for the carrier and bearing, would have figured out that optimum distance, and designed to meet it.

Bottom line, the face of the steel bearing is a lot more stable/resistant to fore-and-aft wear than the graphite, so that any change in geometry as it moves should me negligible.

Is the problem on the Cubs perhaps with the durability of the new-fangled sealed bearings?

Sooo, what should I do? Do I just live with it, or should I split it and replace it? I'm not too familiar with the clutches in these..never done one before.

Whether your rear main is contributing to it (not real likely) or not, you have a problem with your clutch. Whatever it turns out to be, short of something as simple as a linkage adjustment fixing it (again, not likely), you need to get in there and figure out what's going on.

Split it and fix it is my advice. It's very simple and typical setup as clutches go.

Yes, the quality of the bearing was also mentioned by some as a possible reason for the short life. Other thoughts expressed were that the steel bearing may not have been a true thrust bearing but more like an axial bearing. Others stated that side to side alignment may be more critical than for the graphite and if the yoke is not properly aligned failure would occur more easily with the steel bearing. Also on the forum someone posted a picture of an interesting arrangement but no one was witness to how it was actually installed. The picture taken through the inspection hole in the bell housing showed an original graphite bearing housing in the yoke and a steel thrust bearing in front of the graphite housing, which no longer had any graphite extending out of its housing. It looked like the steel thrust bearing may have been "floating" on the drive shaft in front of the old graphite housing, which was only used to push the steel thrust bearing against the fingers. This arrangement was reported to be working OK. I assume the thrust bearing had a collar through its center. If the collar just fit loosely over the drive shaft, it would move straight fore and aft on the drive shaft and may be a way to overcome any alignment issues.

The "float" of either the carrier or base for the graphite bearing is a factor. There is a lot of intentional imprecision designed into the way they fit into the fork -- allowing the faces to align with the plane made by the tops of the fingers in the instant before the real pressure comes on. There is enough slop there that either should align okay if in good condition. Trick is (at least in the A/B/C) that there's a cotter pin in the middle of the tapered dowel that the fork hinges on. Positioned such as to prevent the dowel from sliding out too far either side of the torque tube casting, it still allows the carrier to slide back and forth .

I'm not really sold on the axial vs. thrust bearing idea. Thrust-type steel throwout bearings were hardly a new concept by the late 40's. While history may lead us to doubt the business acumen of IH's management, their engineers were first rate. They'd have specced the proper type of bearing.

As for wear in the graphite vs. steel, I come out in favor of less wear on the steel. Within the range that either will float, the gyroscopic effect (I know, there's another, proper, name for it, but it escapes me) of the center of the bearing turning will cause it to center itself up as it picks up speed -- it will shift as much as the carrier allows to center and spin-balance itself. And if it is off center, the fingers of the clutch are not as apt to rip or chip away at the steel face as they would on a graphite face.

Again, not expertise, but general thoughts.

It makes very little difference whether or not a graphite bearing is aligned with the release lever tips. If the bearing is off center all that happens is that the wear circle will not be concentric with the center of the bearing.

Whether you replace your clutch or not would seem like a personal preference thing. If you can live with the chatter, then leave it be. I can tell you that the chatter probably will not go away by itself. If you want to get rid of the chatter you have to get in there and see what the cause is. It might not be very evident. In my previous post I mentioned I had to get an after market carrier. I overlooked telling you we are replacing the graphite bearing with a ball bearing type throw-out bearing. The fingers not being adjusted correctly will cause chatter with both of the types of bearings. I also thought of another cause for the chatter. A broken or weak spring(s) on the pressure plate could also be a cause. It's a little tricky splitting the tractor. You need to support both the back and front halves to split it. The rear half is easy, what with the two wide spread rear wheels. But the front half is another story. It wants to tip over if you don't have a wide spread support mechanism. Good luck no matter which path you take.