I have a Allied 50" rear mounted blower Mod. #YC6010 and the yoke on the blower end brakes before any of the shear pins do. The yoke has a split from the end almost to the ears for the u-joint. i have had the blower for 13 years and replace it every 2 years, no help form the dealer. The yoke is the weakest part of the system. looked at a different style of yoke but can't find a replacment. i have spent over $500.00 in replacment costs of the years! Might have to look at a different PTO shaft.
snowblower pto problem
- Thread starter Troy Falk
- Start date
Welcome to TBN. 
kco
Veteran Member
I have limited experience with equipment but a few things come to mind.
1. Are the shear bolts correct sizes and grades ?
2. is the PTO shaft phasing correct? Improper phasing puts more strain on the components. When replacing the yoke you must make sure the ends align correctly on the splines, and when putting the two halves together they must be correctly aligned. Three-sided shafts will only go together one way but with square shafts you have a 50/50 chance (assuming the yokes are installed correctly to start with) of misaligning them if you aren't aware of phasing.
3. Is the PTO shaft angle appropriate? Some recommend the angle should be no greater than 20 degrees.
4. Is the blower size appropriate for the tractor? Over working a blower on a too powerful tractor might cause failure over time. Probably the failure would not be handled by shear bolts as they are designed for shock.
1. Are the shear bolts correct sizes and grades ?
2. is the PTO shaft phasing correct? Improper phasing puts more strain on the components. When replacing the yoke you must make sure the ends align correctly on the splines, and when putting the two halves together they must be correctly aligned. Three-sided shafts will only go together one way but with square shafts you have a 50/50 chance (assuming the yokes are installed correctly to start with) of misaligning them if you aren't aware of phasing.
3. Is the PTO shaft angle appropriate? Some recommend the angle should be no greater than 20 degrees.
4. Is the blower size appropriate for the tractor? Over working a blower on a too powerful tractor might cause failure over time. Probably the failure would not be handled by shear bolts as they are designed for shock.
kco
Veteran Member
It seems like your statement in the original post may be right--you may have to go to with different PTO shaft.
Perhaps others have some different suggestions.
Briana03
Elite Member
WELCOME to TBN
I moved your thread to the Parts/Repairs Forum.
I moved your thread to the Parts/Repairs Forum.
Winmac
Gold Member
- Joined
- Dec 31, 2011
- Messages
- 367
- Tractor
- Landini 6860
When the shear pins are removed, does the driveline acctually slip? It is not uncommon for the components to sieze together rendering the shear pins moot. When installing shear pins they are not meant to be tightened, this provides an aditional clamping force, that can double or tripple the failure point.
Pto shaft failure can also be atributed to improper installed length or operation at extream angles. What type of tube do you have? Square, spline, lemon, etc...
Winston
Pto shaft failure can also be atributed to improper installed length or operation at extream angles. What type of tube do you have? Square, spline, lemon, etc...
Winston
Craig Clayton
Platinum Member
This is becoming my favourite line , could you post a few pics?
I suspect you are having an angle problem on the U joint.
I have also damaged my U joint on my 3 PTH post hole auger from excess angle cranking.
Some day I will get it repaired.
I bought a NEW 1976 Dodge pickup with a 2 piece drive shaft that developed a vibration.
The end of the story is I was able to put in and remove the vibration by doing a 180 on one of the U joints. ( shaft rebalanced etc etc etc)
Craig Clayton
I suspect you are having an angle problem on the U joint.
I have also damaged my U joint on my 3 PTH post hole auger from excess angle cranking.
Some day I will get it repaired.
I bought a NEW 1976 Dodge pickup with a 2 piece drive shaft that developed a vibration.
The end of the story is I was able to put in and remove the vibration by doing a 180 on one of the U joints. ( shaft rebalanced etc etc etc)
Craig Clayton
Is it possible that your pto shaft was never trimmed to properly fit your tractor? If this was the case it could be too long resulting in lots of pressure on the pto shaft toward the gearbox resulting in premature failure of your shaft/gearbox components.