HS40 PTO C Clip


Active Member
Does anyone have a part number for a Tecumseh HS40 PTO shaft C Clip? It fits between the bearing and the seal.

Thank you!


Well-Known Member
28539 for the clip and 28540 for the seal, both should still be available parts through certain vendors as they remained the same through many years although the sidecover itself was updated a few times over the years

If that engine was literally running without those items installed that's a bad thing. without the clip the crank is allowed to pound back and forth on the case and bearing, not to mention causing excessive movement on the rod and other moving parts. If the seal was incorrect or did not seal correctly etc., the problems that would cause, dirt in and oil out! With those parts missing or wrong its obvious it was "worked" on and if you have not had it opened up I urge you to do that before just putting those parts on. the bearing really needs to be looked at if it was run this way at all and probably put on the list of parts to change. The side cover also needs to be looked at really well, hopefully with the clip and seal missing that means that they may have been smart enough to remove them before trying to get the side cover off, but the fact that the parts were left off and it was being run that way......well that says whoever was working on it lacked some common sense :laugh: The bearing is retained to the cover via some washers and screws, and it needs to be securely mounted to the cover, if not the clip wont do anything as the bearing will just be locked to the crank and bang back and forth in the side cover along with the crank.

for future reference, all the parts numbers you are looking for are mostly found on the parts explosions that are easily found on the internet at major retailers (like partstree or jacks small engine) The actual photos and the way they are listed are confusing though as the drawings are generalized, and may be scattered between different sections, your clip and seal is a good example, the seal will be listed in the main explosion, but the bearing are clip are in section 2.

The other thing is if its not listed in part numbers side, that means that means it did not come on that particular engine even though it may be shown on the drawing.
The detailed and educational answer above provided by marcus is yet another example of why I (and many others) consider him to be the "guru" of the HS40 engine as I previously stated in your other thread.


Active Member
Thanks Markus,

I've seen many exploded diagrams, but now I know why I could not find the clip - I was looking in the wrong place. My engine was run previously without the clip, but it did have the seal. The corroded PTO gave me reason to look inside, but when the side cover lifted right off I knew there was a problem. The piston, bore, crank, lifters and rod all look good. The rings looked good. Everything inside was great, so I can live with the pitted external PTO. With the C clip installed it should be back in running condition.

I know I speak for everyone when I say how much we appreciate your expertise!



Active Member
Creia, you are so right! I appreciate all the inputs from everyone, but if in doubt I turn to the answers in the back of the book (aka Markus)!