730 PTO Noise

[JD60Standard]

I was baling with my 730 today and it started making a banging noise only when the Pto was engaged. It doesn’t do it all the time, and sometimes did multiple rounds before it started banging again. This makes me think it’s some sort of gear alignment issue, has anyone else had a similar problem?

 

[Paul_IN]

I would start by unhooking the baler drive shaft and checking how much play is in the tractor PTO shaft. This runs on taper roller bearings and it’s common for this to be loose. If memory is correct the assembly spec is 0.001-0.004 inches end play in the shaft. It seems possible to me this could cause an intermittent banging. There could be other issues with the bearings failing, the gear train, or clutch mechanism. It’s hard to diagnose from afar.

 

[matthies]

Are you sure something isn't wrong with the baler? Just a thought.

 

[JD60Standard]

I’m going to put the baler on a different tractor tomorrow and see what it does. You could feel the banging through the floor pan of the the tractor, which makes me think it’s the tractor.

 

[m16ty]

I’m going to put the baler on a different tractor tomorrow and see what it does. You could feel the banging through the floor pan of the the tractor, which makes me think it’s the tractor.

It still could be transferring from the baler through the driveline to the tractor.

 

[JD60Standard]

I hooked the baler onto my other tractor and it ran quiet, no banging. I did run the 730 for a while this morning and it wasn’t banging too much, but I did notice that the casting that the Pto clutch is inside was extremely hot to the touch after running for a couple hours, I then switched to my 720. Would all this additional heat mean that the issue is somewhere inside the Pto clutch housing,not the main drive train for the Pto.

 

[Paul_IN]

I hooked the baler onto my other tractor and it ran quiet, no banging. I did run the 730 for a while this morning and it wasn’t banging too much, but I did notice that the casting that the Pto clutch is inside was extremely hot to the touch after running for a couple hours, I then switched to my 720. Would all this additional heat mean that the issue is somewhere inside the Pto clutch housing,not the main drive train for the Pto.

The clutch pack may be slipping at times. I watched a video of a modified fuel system 720 diesel on dyno and the PTO clutch couldn’t hold the power. It made a pretty loud noise when slipping. Slipping will heat up the parts.
How is the oil level? High oil could cause excess heat from churning and a common failure is the shaft seals which lets transmission gear oil in the PTO. Trans oil can deteriorate the PTO friction material again causing slipping.
Does the banging coincide with taking in more hay?

 

[m16ty]

The clutch pack may be slipping at times. I watched a video of a modified fuel system 720 diesel on dyno and the PTO clutch couldn’t hold the power. It made a pretty loud noise when slipping. Slipping will heat up the parts.
How is the oil level? High oil could cause excess heat from churning and a common failure is the shaft seals which lets transmission gear oil in the PTO. Trans oil can deteriorate the PTO friction material again causing slipping.
Does the banging coincide with taking in more hay?

Never heard of trans gear oil leaking into the PTO and causing problems, but I could see it happening. As a 730 owner myself, I wonder if you could just run trans/hyd oil in the transmission? That way if it mixed there wouldn’t be a issue.

 

[JD60Standard]

The clutch pack may be slipping at times. I watched a video of a modified fuel system 720 diesel on dyno and the PTO clutch couldn’t hold the power. It made a pretty loud noise when slipping. Slipping will heat up the parts.
How is the oil level? High oil could cause excess heat from churning and a common failure is the shaft seals which lets transmission gear oil in the PTO. Trans oil can deteriorate the PTO friction material again causing slipping.
Does the banging coincide with taking in more hay?

The level is correct and I changed the oil just before I started baling, it did not stink of gear oil. It seems to bang weather the baler is working at full capacity or not, but intermittently. I plan to do pull the Pto clutch out after harvest is done and if I don’t find anything wrong in there I’ll dig deeper in the rear end and transmission case.

 

[JD60Standard]

Never heard of trans gear oil leaking into the PTO and causing problems, but I could see it happening. As a 730 owner myself, I wonder if you could just run trans/hyd oil in the transmission? That way if it mixed there wouldn’t be a issue.

That’s what the previous owner of my 720 did and it seems to work fine as long as your not doing any real heavy pulling.

 

[m16ty]

That’s what the previous owner of my 720 did and it seems to work fine as long as your not doing any real heavy pulling.

I don’t know, I still work my old 730 pretty hard.

 

[Tx Jim]

Never heard of trans gear oil leaking into the PTO and causing problems, but I could see it happening. As a 730 owner myself, I wonder if you could just run trans/hyd oil in the transmission? That way if it mixed there wouldn’t be a issue.

I've read of trans oil getting into ind pto housing. IIRC trans oil such as 85W-140 will ruin pto clutch linings. I think Hy-Gard in 2 cyl trans would cause gears to make more noise during operation.

 

[Scott 730]

AFAIK Hy Gard is GL-4 rated so there should be no issues with using it in a transmission with straight cut gears. SAE50 motor oil has been used also.

And yes, gear lube can ruin pto clutch discs if the seal fails allowing trans oil to enter the pto housing.