shear pin breakage

[greg_g]

Toby - the 4720 has two PTO speeds; 540 rpm and 1000 rpm.
Are you positive you're mowing at the 540 rpm setting? Because spinning those heavy blades at 1000 rpm PTO speeds can be real hard on a 1/2 shear pin - even if you DON'T hit anything

//greg//

 

[greg_g]

Toby - the 4720 has two PTO speeds; 540 rpm and 1000 rpm.
Are you positive you're mowing at the 540 rpm setting? Because spinning those heavy blades at 1000 rpm PTO speeds can be real hard on a 1/2 shear pin - even if you DON'T hit anything

//greg//

 

[Highbeam]

I have never broken a shear pin on this mower. Check out the photo. The yellow slip clutch is pretty cheap at agrisupply.

 

[Highbeam]

I have never broken a shear pin on this mower. Check out the photo. The yellow slip clutch is pretty cheap at agrisupply.

 

[BB_TX]

Neat idea on the rear wheel, Joe. Never thought about swinging it up like that for trailering. /forums/images/graemlins/smile.gif

 

[BB_TX]

Neat idea on the rear wheel, Joe. Never thought about swinging it up like that for trailering. /forums/images/graemlins/smile.gif

 

[Toby873]

Snapped another one after hammering the last one out. Mowing a previously mowed field. PTO is right speed, not hitting anything. Slip clutch? Does it still require a shear bolt?
Toby

 

[Toby873]

Snapped another one after hammering the last one out. Mowing a previously mowed field. PTO is right speed, not hitting anything. Slip clutch? Does it still require a shear bolt?
Toby

 

[Highbeam]

Swinging that wheel up saves me from a big overhang and the potential legal hassles with that. I trailer a lot of miles and like having that wheel swung up. The tailwheel doesn't pivot around either, it just sits there.

The slip clutch is held on by the former shear pin. You use a strong bolt though so that it won't shear. I ordered my RC with it so I didn't have to do the install but the PTO shaft might need to be shortened a little.

This doesn't explain why the poster's shear bolts are shearing so easily though.

 

[Highbeam]

Swinging that wheel up saves me from a big overhang and the potential legal hassles with that. I trailer a lot of miles and like having that wheel swung up. The tailwheel doesn't pivot around either, it just sits there.

The slip clutch is held on by the former shear pin. You use a strong bolt though so that it won't shear. I ordered my RC with it so I didn't have to do the install but the PTO shaft might need to be shortened a little.

This doesn't explain why the poster's shear bolts are shearing so easily though.