Cub Clutch

[jpate831]

I have a '47 Cub I restored a few years ago. Recently, I've started having issues with the gears grinding a little when I shift from neutral to anything. I can start it in gear with the clutch pressed down with no issues. I can shift from one gear to another with no issues. But if I let it run in neutral with the clutch out for any length of time, I'm going to grid a gear when I try to shift. I put a new clutch and pressure plate on when I restored it. Do you think I need to adjust something, or do I have some other problem?

Thanks.

[Eugene]

Thinking pilot shaft bushing needs lubrication.

Search function, top of page, look for pilot shaft bushing lubrication. There should be a couple of tips on how to lubricate the bushing without splitting the tractor.

[Scrivet]

Depending on how long you are waiting between pushing the pedal down and trying to put it in a gear you may not have a problem. It takes a couple seconds for the driveshaft to stop spinning once the clutch is pressed, even more if you have the RPM's up. Engage the PTO and watch the PTO shaft at idle, it will be turning at the exact same speed as the drive shaft. If the PTO shaft is still turning after holding the clutch down for five seconds (actually timed or count one Mississippi, two Mississippi, etc.) then you probably have a dry pilot bushing as Eugene stated. Otherwise you're most likely rushing to shift on a non synchronized transmission.

[LRiddle]

Here is a pretty good thread on the topic. I need to try this trick myself.

viewtopic.php?f=1&t=65053&p=530560&hilit=Pilot+shaft+bushing+lubrication

[JohnMihevic]

If you installed a new pilot bearing it may be too tight. I installed a new clutch, pressure plate and pilot bearing. After I got the tractor back together, I could not select any gear from neutral, without grinding the gears. I reduced the clutch free travel to zero and still could not get the gears to stop. With the engine off and rear PTO engaged, I noticed I could turn the rear PTO shaft very easily by hand after depressing the clutch pedal only half way, so the clutch was releasing and not causing the drag. The only thing left was the new pilot bearing which seemed to have enough clearance with the clutch alignment tool. I also soaked the bearing in engine oil for one day and applied grease to the shaft end before putting the tractor back together. I decided to “wear in” the pilot bearing. I figured it would take a few hours and did not want to put a load on the throw out bearing, and crankshaft bearing with the clutch depressed and the engine running. I rotated the main shaft with an electric motor driving the PTO pulley that I use for my C3 mower (see attached photo--I had trouble with download--I thought I could download and imbed the pic--I guess you can click and open it). I kept the clutch depressed by wrapping a tow rope around the front axle cross member and hooking it to the clutch pedal. With the pulleys I used, the shaft speed was 1100 RPM. About every hour, I checked to see if the gears would still grind when shifting from neutral. After about 5 hours of “wear in”, I could depress the clutch, wait a few seconds and shift from neutral to any gear with no grinding.

John M.

Clutch6.pdf

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