Excessive crankshaft endplay.

[Angry Mechanic 0]

Hi everyone, I have a K301S in my 1977 wheel horse that I bought this past summer. Supposedly rebuilt, runs good no smoke. After finishing mowing my lawn yesterday, removing my earplugs I could hear more noise than I remember hearing from my engine prior to that moment. Inspected engine more closely and determined that excessive crank play was what I was hearing, pushed on flywheel side, then on clutch side and can see a lot of movement back and forth and hear klunk when pushing. When engine is running and clutch is engaged it side loads crank so you dont hear the klunk from the slop, but as soon as you disengage that side load you start to hear it.   When I came home from work today with my Magnetic base dial indicator I went straight to the pole barn and checked crank play.   Cold engine and 48 degrees out I could see no movement so put dial ind on flat portion of flywheel screen ( I know its not the best spot) and it showed only 6 thousandths movement..... Thats great. Started and ran engine with  tractor parked for about 5 minutes I think, shut down and pushed crank both ways and that darn klunk and slop is back again. With engine warm put dial ind back on and get 33 to 36 thous crank end play! I can push on flywheel and then slowly engage pto clutch to push crank back other direction and klunk... its a jumpy movement which is what has me pondering whats happening, If you get what im saying I smoothly apply pressure to push crank back and at one point it suddenly moves. Could the bearing not have been in the bearing plate all the way when the previous owner reinstalled, and I am having that bearing move more easily  side to side when its hot? I know I want 3 to 20 thousandths end play, Can anyone here speculate what I may expect to be the problem?   I was going to get gaskets and reset crank play, do you think I couldn't get a lot of movement when it was cold just because a tighter fit to the flywheel bearing or am I being dumb?  Perhaps I should repeat the cold test using a  brass punch on each side of the crank  to see if I get the bad crank play.  Sorry for the long post, any ideas appreciated.

[oldredrider 2,553]

.033-.036 end play is way more than shims could fix. You may have a bad crank bearing that has beat up your bearing plate. Since the bearing plate is aluminum (soft material) and the other bearing sits in cast iron, I would pull the bearing plate and inspect it and the crank bearing.

[Shynon 7,475]

I think I would also pull the connecting rod cap off and see it the connecting rod or crank are worn due to the .033-.036 end play,

 

 from a fellow Minnesotan

Edited September 28, 2016 by Shynon

[prondzy 3,883]

 and 

[Angry Mechanic 0]

Thank you for the advice, If I have time this weekend I will dive further into it and take a look  at the bearing plate first.  I wasn't  planing on having to do anything serious to the motor for a while but oh well.  Its 57 degrees out and engine is cold and I can push crank back and forth with audible klunk, maybe yesterday I wasnt putting enough force into it.   Thanks again.

[Molon_Labe 731]

Had the same issue with a Kohler M16 with excessive end play. The engine had been apart before and it looked like whoever did it put every shim in the overhaul kit back in it. The shims on the left between my thumb and index finger were tossed out and the ones on the right went back in after checking the thickness with a micrometer and subtracting that number from the end play. Hope your fix is as simple as this one was.