PTO Drive Outer Housing Spinning Question

[wstr75]

I replaced the safety tube today that covers the drive shaft on my Howse rotary mower. The previous safety tube had fatigued and broken away at the tractor connection end and exposed the u-joint.

Question: Does the safety tube rotate when the implement is engaged? I secured the little chain that came with the tube but it immediately was jerked apart when the pto was engaged. My assumption is the tube rotates when the pto is engaged but that it would stop rotating and slip if something where to get entangled with the tube.

I checked the tube and it readily slipped when held (this is with the motor not running).

 

[Willl]

I've always thought the chain was to secure it from spinning ?

Non the less, I personally wouldn't have replaced the cover. Always thought it wasn't a good idea to get close to a bare shaft while rapidly spinning.

 

[aczlan]

I would shoot some grease into the "bearings" at the ends of the cover. The chains should be able to hold the cover still when the PTO is on.

Aaron Z

 

[Gary Fowler]

I just check mine when I hook up to make sure they will slip but I never hook the chain, in fact I removed the safety chain when I got the bush hog. I think that is more dangerous than not having a guard. That flimsy little chain and hook could come unfastened and slap you a few times doing some major damage if it came undone or become a projectile. There is enough friction to really spin that chain if it comes loose. As long as it stops spinning if something gets into it, that is all the safety you need. Best safety is to stay away from spinning shafts even if they have safety guards on them

 

[wstr75]

I truly appreciate these replies. It makes me feel better and confirms my assumptions about the safety tube covering over the PTO drive. As a boy in the 1960s I drove tractors without PTO covers and knew to be careful at all times. As a fifty-something man who has recently gotten back into tractors, I was questioning my reasoning. Thanks for helping me understand.
Bill in NC

 

[3035user]

If they were supposed to turn why would they put them on? I always hook my chain up.

 

[Skyco]

Both PTO driveshafts I own ripped the chain out almost immediately...there needs to be a better system for them to remain stationary while the shaft spins inside.

 

[zzvyb6]

The outer shield should not be rotating. Its kept stationary so that if a pant leg, shirt sleeve, glove, baler tie string, tarp cover, corn stalk, hat, boot or sock touches it, it won't be grabbed and pulled into the shaft and wound up. Now imagine a jacket sleeve getting caught while your arm is in the it.

A few years ago, a fellow was mowing the side of a 4 lane highway just 2 miles north of here. People stopped only when the tractor ran out of fuel. The kid operating it had gotten a pant leg caught, probably when he jumped the pto shaft to get to the other side of the mower. He probably died instantly, but was spinning around the shaft with body parts flying off for 2 hours. And, nobody realized it had happened. I knew him as Rick....

 

[wstr75]

Well, if the tube is meant to be stationary, it is going to need something more substantial than the weak chain that came with the tube. Perhaps a stainless cable. Maybe secure it at the gearbox end and also at the tractor PTO end.

Anybody here rig up something more substantial to keep the safety tube from spinning?

Bill in NC

 

[JimRB]

Not that I have thousands of hours of bush hogging experience but I have used bush hogs with pto shafts covers for 15 years. I have never had a chain fail. I have had some cables fail. Really the chains are not taking any huge amount of torque. That little plastic attachment point would fail before a chain would fail. If that cover has that much friction then that needs to be looked at. Of course if you choose to sit or stand on the cover while the shaft is spinning you might experience disaster.