Blade comes loose and spins freely

[FDSJr 3]

I have an ongoing problem with my 42", 3 blade, side discharge deck.  No matter how much I tighten the nut that holds the blade on the spindle, it comes loose after a couple of hours of use and spins freely on the spindle.  It is not all 3 blades -- only one of them.  My local dealer said to be sure that I have the correct washers on the spindle.  I do, and that doesn't seem to help.  I tighten it down, sometimes using an air impact wrench, and a couple of hours of use later, the blade is spinning freely again.  Has anyone encountered this problem and how did you solve it?  Thanks. 

[oldredrider 2,547]

If you have the correct washer beneath the nut, try some blue LOC-TITE on the threads. If that doesn't work, try a new nut on the shaft.

[FDSJr 3]

Thanks.  I definitely have the correct washers on it.  I have used LOC-TITE on it in the past, but I don't recall if it was the blue version.  Maybe LOC-TITE and a new nut will help solve the problem.

[Lagersolut 613]

1 hour ago, FDSJr said:

Thanks.  I definitely have the correct washers on it.  I have used LOC-TITE on it in the past, but I don't recall if it was the blue version.  Maybe LOC-TITE and a new nut will help solve the problem.

 

 

Blue is for removable - Red is for permanent long term

 

I had an oil pan plug on the wife's car that I could take off with my fingers twice - 1st time figured just didn't tighten it enough - 2nd time the Blue LOC TITE came out - now it stays tight - never had a oil pan plug do that before either and we all know it's the last thing you want falling off a vehicle .

[Don1977 604]

I would get a new nut and try that. Something is probably stripped. Hopeful it's the nut and not the spindle shaft. I have had that problem and had to get a new nut.

[doc724 924]

Before you get a new nut, look at the threads on both.  I agree with Don 1977, one or both of the parts is cross threaded and stripped

[Tankman 3,515]

Check nut and spindle threads. Then use Blue Threadlocker (Loctite). Red Threadlocker requires a torch to remove a nut.

Be sure to post your success!  We're nosey Horses!  

 

My thought, "replace the nut."  Good luck.

[FDSJr 3]

Thanks very much to everyone for the comments and suggestions.  I will work through it and let you know how it goes.  Thanks again.

[chev0545 231]

make sure the 11/8 nut on spindle isn't spinning when tightening the blade nut.i use a long handle 11/8 wrench I got from a vendor on here.

[cleat 4,992]

Should not need loc-tite, actually that may make it worse.

 

Nut should self tighten with use.

 

I always make sure the nut spins on easily by hand then apply some never size to the threads and torque it on with an impact.

[FDSJr 3]

UPDATE:  This is somewhat baffling.  I have now had a chance to thoroughly check the deck.  The loose blade problem only seems to affect the center blade -- the other 2 are fine.  What is interesting here is that the nut does not appear to be coming loose.  The blade itself somehow seems to be loosening under the nut (and washer) without the nut coming loose. The nut is just as tight as when I first torqued it down.  Since this has happened several times, the loosely spinning blade has caused the hole in the blade to enlarge very slightly.  It is also possible that a very slight groove has been worn in the spindle shaft.  I am going to make a guess here that this loose fit of the blade on the spindle shaft will eventually allow it to spin freely - no matter how tightly I have torqued down the nut.  I am considering starting fresh with a new spindle shaft, new blade, new washers, and new nut.  If this doesn't fix the problem, I have no idea what will do it.

[gwest_ca-(File Mod) 10,513]

Take the blade off and run the nut back on to see if it will go past the thickness of the blade. Sounds like the nut is tight before the blade is. Possibly the threads are damaged or not enough threads?

 

Garry