3-point Lynch Pin Length

[Beltzington]

My RC cat 1 pins are about 4" long which leaves about 2" of slop on each side of the lift arm ball. Should the pins be shorter, could be a coincidence but it seems like I have been loosening up nuts and bolts lately, had one of the pins on the RC fall off and the right lift arm came loose where it mounts to the tractor. I am wondering if the long pins are allowing the attachment to exert more force on the 3-point than normal.

 

[jenkinsph]

I would use the shortest pins that will fit with only a little end play.

 

[LD1]

And do something to prevent the pins from loosening. Loctite? Lock nut? Lock washer? Stake the nut? Drill and pin the nut? Tac weld the nut? Drill and set-screw the nut?

Tons of different methods

 

[JimRB]

I second the shorter draw pins and tightening up the arms so there is little side to side slop. My tractor has turnbuckles so it is easy to take slop out. Note those Cat 1 draw pins torque to about 435 lb-ft according to my JD mower manual. I have a 4' breaker bar that I just lean on to torque them. The used mower I just picked up that was less than a year old had loose blade bolts and draw pins. Both the blade bolts and the draw pin nuts seem to need over 400 lb-ft of torque. Properly tightened they probably will not loosen up. Of course you are supposed to double check that things are tight after 10 hours of use.