Harbor Freight QH interference with PTO shaft

[number9]

I run the HF QH and on occasion have had it contact the PTO shaft of my LandPride finish mower. It only happens when I am backing up a bank. The deck starts up the bank and as it rises the PTO shaft comes in contact with the bottom of the QH. Makes a vibration something awful for sure. I thought about cutting the QH right under the top hook and welding in a section of thick walled pipe cut in half to make an upside down U for the shaft to have clearance. That would work, but I hated to hack up the QH.

So, I got some 3/8" x 2" flat stock at TSC and just recreated the lift pin mounts and welded it on top of the existing mounts. Haven't used it yet, but this will raise the QH 2-1/4" higher above the PTO shaft and I think it will work out fine.

Just thought I'd post as I can't be the only one that's ever had this happen.

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[bandaidmd]

I don't think that problem would be specific to just the HF brand. With the exception of width all the brands seem to be pretty much the same dimensions in the horse shoe.

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[hodge]

Keep us posted- when I back my finish mower up a bank, the angle of the universal joint gets steep enough that it shakes. I will be curious if the QH is the issue, or changing the angle of the u-joint when the back of the mower rises.

 

[number9]

I bet it's your QH. That's the same thing I thought, that the ujoint was binding up, then I happened to be backing up slowly once and lowering the deck in a certain spot and the vibration started, and I seen the QH was on the PTO shaft.

Since that time, anytime I've felt / heard the vibration I look to the PTO shaft and see the QH on it.

My RC deck doesn't do this and I back it up banks near vertical (exaggeration). Then I notice that the gearbox on the RC sits down on top of the deck, where the gearbox on the FM sits up on top of the belt & pulley housing, so it's an easy 6" or more higher.

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[hodge]

I don't have a quick hitch. My tiller does the same thing, if I have it raised very high, or have the top link adjusted too far forward.

 

[North Idaho Wolfman]

I've heard of this happening when the PTO shaft is to long too, It binds.

 

[hodge]

I've heard of this happening when the PTO shaft is to long too, It binds.

That can be, but not in my case. Both shafts are fine on length.
Universal joints have a fairly narrow angle of operation. Go past that point, and they start to bind. They can get out of phase, too. For instance, if the implement isn't adjusted in plane/level with the tractor, the u-joint on the implement, when lifted, can be at a different angle that the u-joint at the PTO shaft.

 

[BadDog]

That's not normally what is meant by "out of phase" on a drive line. Out of phase usually applies to u-joints not clocked the same. When you put the 2 pieces together, choose the spline engagement that aligns the yokes, then it is "in phase". Both stubs should also be made parallel with angle not ever exceeding the max rating for the specific joint, which is what you were describing.

 

[hodge]

That's not normally what is meant by "out of phase" on a drive line. Out of phase usually applies to u-joints not clocked the same. When you put the 2 pieces together, choose the spline engagement that aligns the yokes, then it is "in phase". Both stubs should also be made parallel with angle not ever exceeding the max rating for the specific joint, which is what you were describing.

I know that. I didn't know another term for the two joints to be traveling angles that don't correspond.

 

[North Idaho Wolfman]

Hodge, I think it's called being out of parallel when that happens.

 

[bandaidmd]

Other than someone welding the yokes on wrong I didn't realize there were any shafts you could slide together in the wrong " phaze".
Only ones I have first hand knowledge of will only slide together 1 or 2 ways and the 2 way ones are rectangle shafts so either way is the same phazeing.

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[hodge]

Hodge, I think it's called being out of parallel when that happens.

That sounds about right.

 

[hodge]

Other than someone welding the yokes on wrong I didn't realize there were any shafts you could slide together in the wrong " phaze".
Only ones I have first hand knowledge of will only slide together 1 or 2 ways and the 2 way ones are rectangle shafts so either way is the same phazeing.

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It could happen, unless the shaft is indexed and can't be put together but one way. Otherwise, say with a square or triangle shaft, quarter turning them when you put them back together will get the u-joints outo of phase. It is even easier on a truck with a splined slip joint, since you can easily get things misaligned. If you pull a shaft apart, be sure to mark the two sides so you can get it back together the way it was.

 

[number9]

That did the trick for me. Mowed yesterday in all the same places, all the same patterns, didn't adjust the 3pt at all and no QH contact on the PTO shaft - all the spots before where it'd rub I looked down and it had 2" easy clearance.

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[hodge]

That did the trick for me. Mowed yesterday in all the same places, all the same patterns, didn't adjust the 3pt at all and no QH contact on the PTO shaft - all the spots before where it'd rub I looked down and it had 2" easy clearance.

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Good job there.

 

[North Idaho Wolfman]

Excellent! I've made most of my implements so far, and it's always a challenge to get the geometry just right to make everything work.