Rotary cutter gear box to PTO connection

RX7320inEastTN · Dec 22, 2023

I have a 6 foot Tennessee River Implements rotary cutter (NEW), and I need help connecting PTO to gear box splined shaft. PTO shaft not connected when I purchased the rotary cutter. Rotary cutter has a 90hp gear box with splined shaft. PTO portion has a nut that is visible, screwed on to a threaded "pin" or bolt. But, IF it is a bolt, it does NOT have a bolt head. There is a hole in the splined shaft that protrudes from the front of the gear box, but it does not look like a big enough hole to handle the "bolt" on the PTO side of the connection. I called the place I bought it from, and hopefully they will call me tomorrow. But thought I'd ask here also. Thank you.

repete · Dec 22, 2023

Do you have a slip clutch on the PTO shaft? If you have a splined PTO shaft at both ends and no clutch, you are asking to break something when the cutter hits an immobile object.

RX7320inEastTN · Dec 22, 2023

repete said:
Do you have a slip clutch on the PTO shaft? If you have a splined PTO shaft at both ends and no clutch, you are asking to break something when the cutter hits an immobile object.

I thought I mentioned it has a slip clutch, but I re-read my post and realized I did not write that. Yes, it has a slip clutch. I had this exact same model brush hog on my last tractor, and I had to replace clutch plates.

ericm979 · Dec 22, 2023

If it's like my rotary cutter with a slip clutch, the "bolt" is really a tapered pin that's threaded at one end. The hole it goes in is also tapered, larger on one side than the other. One side has a flat around the hole which is where the nut and washer seat. The pin mates with a groove milled on the gearbox end of the slip clutch. It's a bit tricky to line it all up while working in the safety guard but it's not too hard. I use a long screwdriver that's smaller than the holes to get it lined up.

Mine came with a manual that shows all the parts. If you don't have that you can look up the slip clutch manufacturer and find the manual on their web site.

repete · Dec 22, 2023

If you go through a number of clutch discs you may want to adjust the clutch pressure. I take one of those point and shoot thermometers and just take the clutch's temperature every now and then. If it gets hot when you really load it down, but runs cool in "normal" load you might be about right with the adjustment. You want to on occasions make it slip just to be sure it is not "locked" in the engaged position. Especially if it gets wet and rusts at all.

RX7320inEastTN · Dec 23, 2023

ericm979 said:
If it's like my rotary cutter with a slip clutch, the "bolt" is really a tapered pin that's threaded at one end. The hole it goes in is also tapered, larger on one side than the other. One side has a flat around the hole which is where the nut and washer seat. The pin mates with a groove milled on the gearbox end of the slip clutch. It's a bit tricky to line it all up while working in the safety guard but it's not too hard. I use a long screwdriver that's smaller than the holes to get it lined up.

Mine came with a manual that shows all the parts. If you don't have that you can look up the slip clutch manufacturer and find the manual on their web site.

RX7320inEastTN · Dec 23, 2023

Thank you. It came to me in my sleep last night. Remove that nut that I see on what you describe as tapered pin. Then it will go back in to that milled slot on the gear box side. I'll report back when task complete.

ericm979 · Dec 23, 2023

@repete is right about checking the clutch adjustment while you're there. My dealer did a good job of prepping the tractor but the clutch came adjusted too tight. If it's too tight it won't slip when needed, like when you pull a large rock up out of the ground with the mower.

The manual should give you a starting point for the adjustment.

RX7320inEastTN · Dec 24, 2023

ericm979 said:
@repete is right about checking the clutch adjustment while you're there. My dealer did a good job of prepping the tractor but the clutch came adjusted too tight. If it's too tight it won't slip when needed, like when you pull a large rock up out of the ground with the mower.

The manual should give you a starting point for the adjustment.

Thank you. I will do that today.