pitman shaft removal

[Donn Hewes]

Here are a couple photos to show how I use a clevis to keep from breaking the pitman flywheel. You can jusr put a wrench right on the fly wheel, but if the pinion is tighter than usual there is a risk of breaking the flywheel. I have done that once.

[Ed Thayer]

Don,

Is that a #7 mower? Is the flywheel attched via the nut on the flywheel?

Ed

[Donn Hewes]

Hi Ed, that is a number nine mower. The process for removing the flywheel shaft is similar for both. The flywheel is pressed and peened on the end of the shaft. By a combination of grinding and a press, the flywheel can be removed from the shaft, but usually it is not. The only reason to remove the flywheel from the shaft would be a broken flywheel or a replacing a scored shaft. the shaft connects the flywheel to the gear box, and usually the shaft is removed to correct a leaking seal, or replace a brass bushing when there is wear or excessive play on the fly wheel end. On a number seven there is a bushing supporting each end of the shaft and a number nine has a bushing on the flywheel side and a baring on the gear box end.

It is a pretty regular desire to remove these shafts during most rebuilds just to change the seal and check the bushing. The shaft is held in by a pinion gear that is threaded on inside the gear box. As this tightened while mowing you would think they would be impossible to remove, however they usually come off with a little effort. They are constantly lubricated and I am sure that helps. the difficulty is to hold the pinion while turning the flywheel. Counterclockwise if you look at it from the front. I use a small crow bar that goes in the gear box and comes up between the pinion and the drive gear, locking them up. With the clevis on the flywheel I can apply force with out too much concern for breaking the flywheel. Which I have done.

In the first picture you can see one hand is ready to hold the crow bar in the gear box while the other is ready to turn the flywheel. if it is tight this is easier done with two people insted of two hands, but I have done it by myself.

[Ed Thayer]

Great description. Thanks for clarifying. I picked up a #7 that is complete and think it may need some minor work. The shaft feels tight and turns freely. But until I pull the gear box cover off I do not know if it has oil in it and if it will need seals or not. I would like to rebuild it and get it operational.

Ed

[Donn Hewes]

I have worked with several number sevens and like them just as well as the nines. given the age of these machines, the condition of the mower is what determins if it is a good one or not. Good luck with it. Donn

[Jay]

Thanks, Donn for the clevis idea and the good picture of it as well. I haven’t broken a fly wheel yet- and I hope to keep it that way (with a little luck!). I too find that the condition of the mower is more important that whether it’s a #9 or #7. Jay

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