Learning the hard way

FrozenOrange

Active member

Equipment
L3901HST, B7100
May 8, 2017
137
56
28
North Pole Alaska
I learned some things about PTO shafts. Like a shear bolt must not be replaced with a grade 8 bolt. There are horsepower ratings for the equipment and the shafts. Little things ya overlook.
I inherited a 48" rotary cutter, tiller, post hole auger. They work great on my old 7100. The old machine had a tire problem and I wanted to get the pasture mowing done. What the heck. Put the rotary cutter on my L3901. An hour later and nearly done I find a stump. Normally the shear bolt would give and I'm out nothing but a cheap bolt. I never thought to look at that bolt. I never thought about a 20 hp shaft on a tractor with far more power.
Now I have a new shaft for the correct hp and have correct shear bolts. Here are pics of the old shaft
20201007_131612.jpg
20201007_131628.jpg
20201007_131612.jpg
 
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85Hokie

Moderator
Staff member
Lifetime Member

Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
10,745
2,551
113
Bedford - VA
That is torque .... and lots of it!!! I have never seen that wind up like that - seen a few shafts beat something to hell and back .....

Glad no one was hurt. And don't beat yourself up - IF someone every says = "I have never screwed up," they lied!!!!

Hell - first screw up I did was dump a heavy piece of wood on my 1 hour old brand new tractor that I had not made the first payment on yet ... I have the dent to remind me ..... everyday!

Good story - thank you for the true story! And a teaching lesson.
 
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SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
7,197
555
83
USA
Might be able to repurpose that end as a screw point for a post hole digger.............. :D
 
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Nicfin36

Well-known member

Equipment
L2501 HST, BH77 Backhoe, SSQA Loader ZD1011 Mower
Jun 19, 2019
1,016
466
83
Decatur, AL
I looked at the picture before reading and my brain couldn't comprehend what that was. Wow! Live and learn. :)
 

FrozenOrange

Active member

Equipment
L3901HST, B7100
May 8, 2017
137
56
28
North Pole Alaska
That is torque .... and lots of it!!! I have never seen that wind up like that - seen a few shafts beat something to hell and back .....

Glad no one was hurt. And don't beat yourself up - IF someone every says = "I have never screwed up," they lied!!!!

Hell - first screw up I did was dump a heavy piece of wood on my 1 hour old brand new tractor that I had not made the first payment on yet ... I have the dent to remind me ..... everyday!

Good story - thank you for the true story! And a teaching lesson.
I bought three new shafts to replace the three I had. On one older shaft (in picture) the shield was falling apart due to years of sun. I figured that was a safety issue as well.
 

mcfarmall

Well-known member

Equipment
Kubota M5660SUHD, Farmall C
Sep 11, 2013
1,410
1,691
113
Kalamazoo, MI
Glad you weren't hurt but that is cool as heck! Seriously, I'd hang that on my shop wall in a heartbeat!