[jeffrey.w.ramsey]

4105 owner here with 588 hrs. Fantastic tractor and have had zero issues. After blowing out all the grass and dirt I noticed these bolts are loose. You'll notice someone marked the frame but not the bolt heads. Has anyone experienced this before? Best guess how they got loose?
Semper Fi!
Jeff

 

[dave_r]

Vibration most likely (IMHO). Maybe spin them out, put a dab of blue threadlocker on them, then reinstall (one at a time so it doesn't fall apart on you).

 

[8808hill]

that is scary. I would replace the bolts.. first tighten all bolts and then replace one at a time after blowing out holes and adding thread locker. be sure to fully torque... when inspecting the holes make sure the bolts are not bottoming out, or close to it.. Also be sure of new bolts quality and length.

 

[Alien5044]

Nylock nuts, if they have nuts, might be another option. There are also 'crushed' lock nuts that have a slightly deformed thread to resist vibration loosening.

McMaster-Carr has a wide selection of these types including mil spec'd, if you want to be sure they stay where you put them.

Every time I do my greasing and blade sharpening, I have a good look around at fasteners for security. In recent decades, fasteners seem to have become cheaper and cheaper. My old Sears Super 12 out in the barn, has split lock washers and used 9/16" bolts and nuts, they never rattled loose.

 

[Alien5044]

Just curious here, did you buy the machine new? Does MTF have other 4105 owners that have the same marks on the frames, implying they are factory QC of frame bolt assembly? Are these bolts with nuts or are they going into a casting or other tapped and threaded part?