PTO bogs down while mowing

[mac1520]

Got a bit of a problem that started on my New Holland TC34DA (HST) earlier this summer. With the land pride 72 inch mower going on the rear PTO, if I hit thick grass, the PTO BOGS way down. Engine RPM says steady, but you can hear the mower just slow way down. Every now and then the Rear PTO shift knob pops out of gear. Goes back in with no problem, but happens from time to time... Changed all Hyd fluid & Filters... Still does it. I have 760 hrs on it and everything else works fine.

Appreciate any help.

 

[Soundguy]

No engine rpm change, but pto rpm change? = very bad. They are ratio locked.

I'm not up on that new machine, but if it is ind pto, that clutch is slipping either from gross overload ( not likely if engine doesn't bog ) or perhaps if hyd, the clutch pack is not being pressurized.

 

[kthompson]

Are you sure the mower is really dropping rpms and just the heavier grass load has change the sound of the air is able to make around the blades? Is this a rough cut or finish mower? If finish mower sure the belt is not slipping? If rough cut does it have a clutch on the pto shaft? If so could it be slipping? kt

 

[mac1520]

No engine rpm change, but pto rpm change? = very bad. They are ratio locked.

I'm not up on that new machine, but if it is ind pto, that clutch is slipping either from gross overload ( not likely if engine doesn't bog ) or perhaps if hyd, the clutch pack is not being pressurized.

Yea... Not happy with the idea of replacing the clutch, but wondering if the PTO Clutch valve is not doing its job correctly causing the clutch to slip?

 

[jeff9366]

On my Land Pride R/C the PTO slip clutch on the R/C is adjusted using a socket to increase or decrease spring pressure.

When was the last time you sharpened the blades on your R/C? If blades are dull, the increased pressure of resistance and clippings load may be making the slip clutch slip, which it is supposd to do.

 

[mac1520]

Are you sure the mower is really dropping rpms and just the heavier grass load has change the sound of the air is able to make around the blades? Is this a rough cut or finish mower? If finish mower sure the belt is not slipping? If rough cut does it have a clutch on the pto shaft? If so could it be slipping? kt

It's a finish mower and positive it's definitely the mower & PTO slowing down. The grass is cut each week, so the mower should be able to cut it with minimal issue. RPM stays rock solid, you don't see the tach needle move at off the 540 at all. Looked at belt and it's good, regreased all the fittings, blades spin nice and easy by hand. All great questions...thx

 

[oldnslo]

Mac1520
I looked at the parts breakdown for this model and didn't see a reference to a PTO clutch. Do you have to depress the clutch and then engage the PTO on this model. When you press in the clutch does the tractor also stop moving?

If yes I would adjust or check the freeplay on your clutch.

 

[mac1520]

On my Land Pride R/C the PTO slip clutch on the R/C is adjusted using a socket to increase or decrease spring pressure.

When was the last time you sharpened the blades on your R/C? If blades are dull, the increased pressure of resistance and clippings load may be making the slip clutch slip, which it is supposd to do.

Had my neighbor come look at the deck, but since it's a finish mower, there was no adjustable clutch. I had the same thought initially about the blades, so sharpened them all two weeks ago, figured since it was a HST, I'd try new Hyd oil and filters (it was old - 450 hrs since last time).. No change.

 

[mac1520]

Mac1520
I looked at the parts breakdown for this model and didn't see a reference to a PTO clutch. Do you have to depress the clutch and then engage the PTO on this model. When you press in the clutch does the tractor also stop moving?

If yes I would adjust or check the freeplay on your clutch.

Interesting... I saw a similar problem on a TC35, and was thinking it had one, but there is no access panel below the drivers seat, so I ordered the repair manual section that covers PTO & Hydraulics. I do have to push the clutch to engage the PTO and yes, the tractor stops moving with the clutch engaged. I will definitely check for the free play adjustment and report back. Thank you!

 

[stuckmotor]

I'm not up on these tractors. If this was my MF with a two stage clutch, I'd suspect the PTO clutch was out of adjustment. The PTO shift knob popping out adds another dimension to the problem. Hopefully it's an inexpensive symptom of something being out of adjustment.