47" blower breaking impeller shear pins.

[tsquared2305]

I've read a number of threads here about JD 47" blowers attached to 2305's breaking shear pins and although some come close to my problem I'm still having issues with the blower.

This is the 3rd winter for the blower/tractor. First 2 winters I never had a problem but now I'm breaking about 2 shear pins per use and it doesn't matter if its 2" of light fluffy stuff or 10" of heavy wet snow. The shaft arm that transfers power from the shaft to the impeller is coming loose allowing the impeller to slid forward and impact the housing.

I've followed the advise from some of the other threads - I've checked the shaft key and it looks good and has never fallen out. The problem seems to be with the set screw that holds the arm to the shaft. Typically the set screw just loosens up to the point the shear pin fails, but I've also had the set pin come out and lost a few. I've tried blue loctite on the set-screws without any luck and have tried a cheater bar on the set-screw. nothing seems to be working.

I've got a bolt in there now with a locking nut on it and that seems to be working, but I've noticed a new vibrations coming from the blower thats likely caused by the out of balanced arm w/ bolt & nut.

I've spoken with the JD dealer I purchased it from and they gave me the idea for the bolt and locking nut, but beyond that they don't have any other ideas.

Any one have any other ideas or tricks to try? I'd prefer not to use red loctite, but at this stage I'm about ready to try anything.

Thanks

 

[Labrat]

I've had the set screws loosen so the impeller slides forward and hits on the bottom of the blower housing. Make sure the impeller is pushed back away from the lip on the bottom.
I would also check the impeller bearing. See if it has any play in it, You may have to loosen the drive chain to check it.
Have you adjusted and lubed the chain?
Could the impeller be out of balance from rock or stone impacts?

Just some things I would start with.

 

[Dutch445]

i think there are a few topics regarding this
issue. some other options are to install a simple
1" split collar to the shaft in front of the coupler,
and tighten so nothing can slide forward.
another is to mark where the set screw is
to contact the shaft, and drill a slight dimple
for the setscrew to nestle in, and use lock-tite
on the setscrew. I would not believe an bolt
that close to the center of that rotation would cause
a balance issue, although your impellar fins may
have had a little deformation from hitting the housing.
sometimes you get a square headed bolt instead of
the allen head setscrew in applications like this anyways.