PTO bolt issue

[Brian B Glynn]

1952 WD45

Issue: Constantly breaking the bolt on the PTO shaft- even Grade 8s. Often after only a few minutes when using a brush hog.

A little history

Oil leak on the PTO gearbox fixed with a new seal last winter is leaking again.
Bolt hole on the PTO shaft is very slightly elongated.
Brush hog spins freely and the gear box holds lube.

Any ideas why I'm going thru PTO drive shaft bolts so quickly?

 

[DrAllis]

Cutting too low and hitting the ground. Driving too fast and over,loading the PTO itself.

 

[Brian B Glynn]

Thanks, but height is where I've always had it- even higher, and speed is the same. This is a new issue.

 

[DoubleO7]

This is a new issue.

Appears to be the same issue as you have had in two previous threads on the subject.

Are you hoping for a different answer than what you got before?

PTO bolt

What do I need for a replacement bolt on my 1952 WD45 PTO shaft. The shear bolt near the pump one.

forums.yesterdaystractors.com

PTO Shear bolt issues

I have a 1952 WD45 and cannot keep a PTO shear bolt in place. I've tried different bolts including a Grade 8 bolt but they always break within several minutes. The PTO unit seal was replaced last year if that makes any difference. The brush hog works well before the bolt breaks. Any ideas?

forums.yesterdaystractors.com

Or maybe you messed up with the chains?

Chains for brush hog support

I have a 1952 WD45 and have a hard time keeping my brush hog at a consistent height. (Long story and I've tried everything with the settings). I'm thinking of welding chains or hooks to the brush hog and some sort of chain adjustment connections set up on the tractor. Does anyone have pictures...

forums.yesterdaystractors.com

Or maybe something inside the pto gearbox you had off has an issue.

WD 45 PTO Gearbox

Do I need to use those goofy acorn type nuts when re-installing my PTO gearbox to the underside of the tractor or can I use regular ones?

forums.yesterdaystractors.com

 

[Brian B Glynn]

Double07, do you have any helpful advice?

 

[DoubleO7]

Double07, do you have any helpful advice?

Already given in your previous threads.

Have you tried any of the suggestions posted in your previous threads?

 

[Brian B Glynn]

Yes, I bought a new over running clutch but need to get a shorter shaft from the tractor to the brush hog. Will the over running clutch help even though I never broke a bolt before without one?

 

[Jim.ME]

Did you change bearings when you changed the PTO gearbox seal? Did anything get changed other than the seal?

Is the cutter shaft free to telescope? Are the u-joints on that shaft in time?

Have you marked the slip clutch sections to see if it is slipping at all? Have you loosened it, made it slip to confirm it hasn't seized, then adjust it back to spec?

Have you gotten and tried using one of the shouldered bolts the shaft is supposed to have in it? Has the extension shaft gotten bent?

An overrunning clutch only stops the cutter from transmitting the inertia of the rotating assembly back through the tractor drive train. Beyond the normal reason to use one, to prevent the tractor being pushed along when the clutch is disengaged, it would lessen/remove the force sent back to the tractor that would occur if the engine was shutoff with the PTO engaged.

Just trying to think of things that might be in play.

 

[Watthour]

Runout in the coupling and U-joint can stress a pin worse than an overload.

 

[DrAllis]

Never broke a bolt before you added the over running clutch ??? Really ??? Get rid of the over running clutch for a while and see what happens !!! If the PTO shaft is bottoming out you are going to destroy something in a gearbox !!!!

 

[Brian B Glynn]

No, I've been running without an over running clutch the whole time. I did buy one last week but my drive shaft from the tractor to the brush hog was too long so now I need a shorter shaft.

 

[Aaron SEIA]

Yes, I bought a new over running clutch but need to get a shorter shaft from the tractor to the brush hog. Will the over running clutch help even though I never broke a bolt before without one?

Overrunning clutch or slip clutch? You NEED a good functioning slip clutch. There has to be something else going on with the mower or it's use. That bolt is NOT meant to be a shear bolt and continued breaking of it points to a bigger problem.
AaronSEIA

 

[Brian B Glynn]

Runout in the coupling and U-joint can stress a pin worse than an overload.

What is runout?

Overrunning clutch or slip clutch? You NEED a good functioning slip clutch. There has to be something else going on with the mower or it's use. That bolt is NOT meant to be a shear bolt and continued breaking of it points to a bigger problem.
AaronSEIA

Tell me more about a slip clutch

 

[Brian B Glynn]

Runout in the coupling and U-joint can stress a pin worse than an overload.

What do you mean by runout?

 

[Aaron SEIA]

What is runout?

Tell me more about a slip clutch

It does what it's name is. Slips when it encounters a load. Usually its a spring loaded disc setup. Holds under normal conditions, but when you hit something it'll slip.
AaronSEIA

 

[Aaron SEIA]

No, I've been running without an over running clutch the whole time. I did buy one last week but my drive shaft from the tractor to the brush hog was too long so now I need a shorter shaft.

If adding 6" for the OR clutch makes your shaft too long, it was too long to start with. Let me guess. Pull type mower and it breaks in a turn? OR clutch isn't going to fix the problem.
AaronSEIA

 

[Fritz Maurer]

If adding 6" for the OR clutch makes your shaft too long, it was too long to start with. Let me guess. Pull type mower and it breaks in a turn? OR clutch isn't going to fix the problem.
AaronSEIA

I gathered that it is a 3 point mower .

 

[DoubleO7]

Never broke a bolt before you added the over running clutch ??? Really ??? Get rid of the over running clutch for a while and see what happens !!! If the PTO shaft is bottoming out you are going to destroy something in a gearbox !!!!

His post #7 says he has one but has not tried it out as the pto shaft is now too long.

 

[DoubleO7]

Yes, I bought a new over running clutch but need to get a shorter shaft from the tractor to the brush hog. Will the over running clutch help even though I never broke a bolt before without one?

Unless you need that pto shaft to use another implement, cut the current pto shaft to the proper length.
A search via your favorite search engine will yield many how-to do it info.
Or if you know the brand of shaft you have now, go to their website for such info.

 

[Watthour]

What do you mean by runout?

Mis-alignment, elliptical, or non-concentric connection or construction of the coupling and/or shaft. The resulting potential imbalance can create forces during operation which can fatigue material, destroy bearings and fasteners, and bend shafts and housings. It would tend to happen more slowly in a 600-ish RPM PTO shaft, but can happen nonetheless.