Shear Bolt Broke On New Deck. PTO Shaft & Gear Box Holes Don't Align.

[RickB]

LandPride uses that ignorant trick of having a smooth cross drilled input shaft for cutters with slip clutch drive lines. It's frigging maddening.

Cheap ass engineering. I suppose they might be the supplier for Frontier, who manufactures absolutely nothing.

 

[CoyPatton]

Your last 2 photos labeled pto side, gear box side, left side, right side to me show that you have an offset in the hole the same direction. Your pto coupler and gear box shaft just need better alignment. A tapered punch may be what you need, or you may need to clean up a burr on the gear box shaft.

I also suspect that you need to do slip clutch maintenance of yearly slipping the clutch. This should be outlined in your implement manual. It is typically done each spring. But owning it for 8 months before use, indicates that maintenance should have been performed.

 

[ptsg]

Why don't they just use something like this?

Just a simple 6 splined shaft on the gearbox input shaft. The M8 x 60mm shear bolt is easy to access and easy to take the broken one out by hand and replace with a new one. If needed, one can simple pull the yoke out a little bit to get more space over the PTO shield on the mower, if it has one that is. No need to mess around with the broken middle piece stuck on the shaft. Smaller bolts, so takes less space on the toolbox. I just carry a small box with 50 of them all the time.

 

[ruffdog]

I must have missed the part about them being rusted solid. The pics don't depict that.

Being that it is dry, maybe the two pieces have galled or partially seized. Whatever. If they were lubed and were free spinning, a simple punch or screwdriver would easily line them up.

 

[RustyA]

If your slip clutch is so tight it sheared a grade 8 shaft bolt the clutch needs to be adjusted or freed up. The grade 8 bolt should never shear off, that's the slip clutch's role to protect your driveline.

 

[RickB]

Why don't they just use something like this?

Just a simple 6 splined shaft on the gearbox input shaft. The M8 x 60mm shear bolt is easy to access and easy to take the broken one out by hand and replace with a new one. If needed, one can simple pull the yoke out a little bit to get more space over the PTO shield on the mower, if it has one that is. No need to mess around with the broken middle piece stuck on the shaft. Smaller bolts, so takes less space on the toolbox. I just carry a small box with 50 of them all the time.

Because it is a slip clutch driveline.

 

[the old grind]

If it's a slip-clutch driveline is the grade 8 vs grade 2 shear bolt a backup in case the clutch doesn't slip then? Clutch doesn't seem to have spared the '8' bolt any grief this time.

btw, I have the type ptsg showed on my Betstco flail mower and don't trust the slip clutch on the KK tiller. Time to rethink whether I'll use both or just the one I don't have to recheck every season.

 

[Leejohn]

That is not a shear bolt. You do not put a shear bolt on that end of a pto shaft.

 

[ruffdog]

After reading the OP's last post I agree with the above....it is not a shear bolt because it has a clutch. That is the reason they put in the grade 8 bolt...because they don't want that connection to sever. A shear bolt yoke will most times have a clip to retain it after the bolt shears while the clutch will not have that feature. It wouldn't be a good thing if the pto shaft/clutch comes off the shaft after the bolt shears. The op should adjust the clutch because the next thing to break may be the tractor.

 

[Midniteoyl]

This is an issue misalignment on both sides of the shaft(s).

Hole #1, lets say the PTO shaft - (Female) is aligned like this ---> |
Hole # 2, gear box shaft - (Male) is aligned like this ---> /

The PTO shaft spins and spins and spins and spins. I have rotated the PTO shaft AD NAUSEM and the holes are still misaligned. I've owned the rotary cutter for a total of 8 months and did not start mowing with it until this spring. It is not rusted. There is only a mild amount of surface rust - Florida is wet.

Talking with local dealer again today and sharing these photos he can confirm that the Grade 8 bolt 1/2" x 3 1/2" is correct. Ayup. He also said, after looking at the photos I sent him, "the machine has a slip clutch built into the drive shaft. Without being there to see why the holes are not lining up I would try to adjust the alignment or use a tapered pry bar".

Do I have a miracle rotary cutter that has both a Slip Clutch and a Shear bolt? Cause the specs on these things say Shear Bolt OR Slip Clutch. This is the repair guy.....

When I asked if I used a pry bar and eff it up more would that void my warranty, he said they can come get it for $100 and haul it to their shop.

Reposting 2 photos, now labled and images of the absolute worst pasture anyone has ever had to mow.... it's a wonder I don't roll my tractor or break a shear bolt every time I've mowed it.

I'm sorry, but if those pics are labeled correctly, you need to tap the PTO shaft on a little more. The misalignment is the same on both sides, and it's not on the gearbox shaft far enough.

If it wont go until it's aligned, it's most likely due to galling/hi spot in the gearbox shaft as stated. I haven't looked up the manual, but there is probably a c-clip/e-ring at the end of the gearbox shaft (PTO shaft side) that is used to retain the PTO shaft in case of a catastrophic failure that could be mangled and holding it up as well..

Also agree with that bolt not being a shear bolt in the traditional sense. It's used to mount and hold the slip-clutch and maybe as a last of defense to protect the mower and tractor in case of slip-clutch failure, which is exactly what it did. You need to do slip-clutch maintenance as well.