5325 and SB1174 Breaking Shear Bolt on Engagement

[justwannafarm]

Looking for some advice here. I have a 5325 w/ Frontier SB1174 snowblower. Yesterday I engaged the PTO after disengaging and broke the shear bolt in the pto shaft where it meets the implement. I replaced it with a zinc one since the grade 2 I had were too short. Guessing the zinc was a grade 5? Today I engaged it once at idle, then brought up to 540 and it was fine for about 5 minutes, disengaged and went to re-engage and snapped the bolt again. both times I was at idle so I don't understand why I keep breaking bolts. The only difference now versus earlier in the season when I used it is that it's extremely cold out so everything is moving much slower (even spinning the auger by hand is harder but it's not binding up on anything)

Do I use grade 2 bolts or go with something higher? I've heard guys using grade 8 but that worries me. I don't want to cause any damage to the shaft or gearbox and would rather keep replacing cheap bolts and keep the blower running the entire time rather than engaging and disengaging.

Thanks

 

[jd110]

It sounds like the pto is engaging too abruptly. I assume you have the EH pto? (engaged with a switch) If so then the pto valve is probably sticking. It should be removed and cleaned or replaced. If you have amanual pto, are you engaging the lever slowly? If so, and clutch still engages abruptly, the clutch disk is probably warped or oil soaked.

 

[justwannafarm]

It's a manual engagement. I guess I could try being a little more gentle w/ it. I didn't think it made a difference but I'll try that. It'll also be a lot warmer the next few days so who knows. Never had a problem w/ the brush hog all spring/summer/fall and snowblower was good until we hit the -17 mark here.