Minimum pto shaft engagement

[Stomper]

I am using my quick hitch with my 3ph blower simply for ease of hook up and unhooking. I dont keep the blower on all the time so the QH makes it much more enjoyable for hooking up. Problem is now my pto is extended more. I took a measurement and the pto halves are engaged 5 inches into each other when the blower is resting on the ground. What is a safe minimum engagement.

 

[RickB]

Typical published minimum overlap of the tubes is 6”.

 

[oldnslo]

How much does the engagement change between lowered and raised?

 

[BrooksAGParts]

Typically if you need to lengthen your shaft you can replace just the steel tubes for your shaft, they are sold in 59" lengths all you need to do is identify the type and series or you can add an overrunning clutch (about $45.00 on eBay) which would add 4-5" of length back into your tubing overlap.

Overrunning Coupler / Clutch 1-3/8" Z-6 Male Spline 1-3/8" Z-6 Female Spline QD | eBay

Thank you,
Brian - Brooks AG Parts

 

[Xfaxman]

Another option is a PTO SHAFT extender:

 

[oosik]

My Wallenstein chipper owners manual only speaks of shortening a pto shaft. My drive shaft is 24" long. My overlap is 3" less at 21" of overlap when the drive shaft is dead level. The minimum overlap(at fully raised or lowered) is right around 19". At 21" of overlap my driveshaft is 3" from bottoming out.I've always heard the recommended overlap should be, at least, 1/3 the total shaft length. 24" shaft - 8" overlap and so on.However - research shows one thing is a constant. There is no hard fast rule.Everybody agree on this- the more hp/torque delivered thru the pto shaft - the greater need for more overlap- 5" seems to be the absolute minimum overlap universally accepted- measure twice, cut once, if the shaft must be shortened. Cut an equal amount off each shaft if shortening- new tubes are the best solution to a shaft that is too short Next would be Xfaxmans recommendation for shaft extenders

You could always remove the quick hitch if you felt more overlap was required. Cheap solution.

 

[RickB]

My Wallenstein chipper owners manual only speaks of shortening a pto shaft. My drive shaft is 24" long. My overlap is 3" less at 21" of overlap when the drive shaft is dead level. The minimum overlap(at fully raised or lowered) is right around 19". At 21" of overlap my driveshaft is 3" from bottoming out.I've always heard the recommended overlap should be, at least, 1/3 the total shaft length. 24" shaft - 8" overlap and so on.However - research shows one thing is a constant. There is no hard fast rule.Everybody agree on this- the more hp/torque delivered thru the pto shaft - the greater need for more overlap- 5" seems to be the absolute minimum overlap universally accepted- measure twice, cut once, if the shaft must be shortened. Cut an equal amount off each shaft if shortening- new tubes are the best solution to a shaft that is too short Next would be Xfaxmans recommendation for shaft extenders

You could always remove the quick hitch if you felt more overlap was required. Cheap solution.

Good info here.

 

[pmsmechanic]

Should be interesting discussion here.

 

[Stomper]

Another option is a PTO SHAFT extender:

View attachment 585948

View attachment 585951

To get the required minimum engagement between the two halves all I need to extend it is 1.5” so I believe this is the cheapest and easiest way to go. Now I am assuming that this adapter goes onto the tractor pto and the shaft hooks to it. Correct.

 

[Xfaxman]

Correct.

 

[rangerfredbob]

Even the overrunning clutch doesn't matter though, if splined on both ends, clutch will work on either end...

I know from experience that 2" of engagement isn't enough , my 5' finish mower shaft had been shortened before I got it and only had about 2" of engagement and it came apart while mowing, didn't do any damage to anything other than stalling the tractor. I put an overrun clutch on it and is good to go (my tractor doesn't have one in the PTO output so was NEEDED anyway, not for the finish mower but for the brush hog...)

 

[RickB]

Even the overrunning clutch doesn't matter though, if splined on both ends, clutch will work on either end...

I know from experience that 2" of engagement isn't enough , my 5' finish mower shaft had been shortened before I got it and only had about 2" of engagement and it came apart while mowing, didn't do any damage to anything other than stalling the tractor. I put an overrun clutch on it and is good to go (my tractor doesn't have one in the PTO output so was NEEDED anyway, not for the finish mower but for the brush hog...)

ORC’s only work on the tractor end, they will not transmit power if installed on an implement.

 

[rangerfredbob]

I think you're right, I thought I had figured it out that they could be either way, but I just went out and looked at the clutch and was wrong... don't feel like spending the time to look deeper into it right now

It's better to have it on the tractor end anyway, I imagine the PTO output shaft is better supported than most PTO input shafts on implements...

 

[cathy liebchen]

I would get the correct length shaft and not have extra links cobbled together that can break

 

[Xfaxman]

I think you're right, I thought I had figured it out that they could be either way, but I just went out and looked at the clutch and was wrong... don't feel like spending the time to look deeper into it right now
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You don't need to spend much time. It is called overrunning or one way because it only transmits power turning one direction. If you turned it around and put it on the gearbox, it would rotate the other direction and the gearbox would not turn.