B7100 Rear PTO Issue

[1967ss]

I have an older model B7100 (1976) I bought a few months ago. I recently bought a tiller and used it to till a half an acre. I hit some rocks and the slip clutch did not slip. Rear PTO starte making a whining/grinding sound. It did this in High, Neutral, Low PTO settings. I shut it off, took it to the Kubota shop. They took it apart and said that there was a roll pin that had sheared (I assume a safety device). They also said some of the gears looked a little wore. they replaced the pin and I brought it home.

This time I adjusted the slip clutch carefully and had it where it would just slip on the dirt. Tightening the screws a little each attempt until it would till 2-3 inches of dirt without slipping. After 30-40 feet of tilling, it did it again.

There was one difference this time. The tractor was behaving different since bringing it back from the shop. Previously when tilling the half acre and when mowing, I had never noticed any issues with the Rear Attachment wanting to push me forward. I assumed I had a live PTO with a built in Overrun Clutch. But after bringing it home from the shop, the tiller wanted to push me forward 2-3 feet every so often when it would break loose. So, here are my questions:

1. Does anyone know where this roll pin is? I don't see it in the old service manual that I have (I think it matches my year). Can I get to it by removing the rear casing?

2. The bigger mystery is why the Rear PTO is behaving differently. Does anyone know why it would behave like it had an Overrun Clutch and then stop doing that after coming back from the shop? The manual seems to indicate a one way clutch is in there. I wonder if that was reinstalled incorrectly. Any thoughts?

Thanks for your help. Not the Labor Day weekend I was hoping for

 

[kubotasam]

I have no info on the roll pin that you are referring to. (Sorry) What I do know is than some of the very early year B7100 did not have the over-running clutch built in. I have what I think is a 1977 that does not have the built in clutch and a 1978 that does have the built in clutch. I would need to go out and recheck the serial numbers to be sure of the years but I think I have them correct.

 

[North Idaho Wolfman]

I too know of no roll pin in the entire PTO drive system????

With the tractor off and the PTO engaged try and turn the PTO the opposite direction of it normal rotation it should free wheel easily if it has a one way clutch in it.

Also It's very uncommon for a tiller to "push you along".
It sound to me that the clutch may be out of adjustment and that is what is going on, but it could be that something wasn't put in there right.

 

[1967ss]

I'm not sure what kind of pin it was, I thought he said roll pin. They replaced some kind of pin, that got it working again, but it didn't last long.

I can rotate the PTO clockwise freely, but every quarter turn there is a click. It can still be freely rotated clockwise. This click stops it from turning counter clockwise. I'm thinking it would not allow counter clockwise rotation at all before it broke and i don't remember this click when rotating clockwise. Now I can turn it counter clockwise for a quarter turn until it hits that stop. Thanks for any help or advice.

 

[North Idaho Wolfman]

Did they give you a part # on an invoice as to the pin.

The click every 1/4 turn the opposite direction should be normal as that should be the one way clutch.

 

[1967ss]

Good idea to look at the invoice. No part # listed, but he had a better description of what he did.

"Tech took center cover off unit and found coupler holding splines onto the unit were okay, but roll pin had sheered off causing noise from PTO. Tech repaired and retested the unit and it is working properly."

So, the pin was part of the coupler. I can't figure out which part is the "coupler".

I'm trying to figure out what I need to remove if I'm going to attempt to fix this myself.

 

[kubotasam]

So if the service order states the took the "center cover" off that indicates to me they were looking into the range transmission. This is where the shifting part of the pto mechanics are. The only roll pin I can find is external to the case where the pto shift lever is pinned to the shift fork. This roll pin failing only happen if the shift lever has to much force applied to it. You are not by any chance needing to tie the lever or hold it to keep the pto engaged? (I am sure you are not or you would have told us that.)

Just to help us out here. You only talk about high, neutral and low on the pto speeds and the parts diagram shows a mid pto so your tractor must have a hydrostatic transmission. Gear drive B7100s did not have the mid pto.

 

[1967ss]

Yes B7100 HST-D (4 wheel drive). The more I have read about this, it does appear they were in the range transmission. Which makes sense, since I cannot disengage the PTO. The noise happens in Low, Neutral, and High so something would have to be wrong at the range transmission, not further back near the PTO. There is a coupler in the exploded view of the range transmission, though no roll pin is called out in the list.



He said something about this coupler and the spline shafts being wore and that replacing them would be the next step if it does it again. This requires splitting the tractor ($1400). So, I'm trying to learn more about this coupler and the roll pin. Perhaps this isn't the original coupler, since the manual doesn't indicate a roll pin, or this service manual isn't an exact match to my year and I need to order one.

How difficult is it to get to the range transmission to get a look at this coupler and potentially replace this roll pin? What all needs removed?

 

[North Idaho Wolfman]

Can you give me the serial # .
The only roll pin I can think of is on the coupler that connects the propeller shaft to the HST unit.

 

[1967ss]

I think that may be the roll pin in question. He said something about propeller when first talking to me, but never mentioned it again. Which is the propeller shaft?

My serial number is 11558 (B7100HD11558).

 

[D2Cat]

Sounds like North Idaho Wolfman has the bead on the problem.

"He said something about this coupler and the spline shafts being wore and that replacing them would be the next step if it does it again. This requires splitting the tractor ($1400)"

All that is true, except the $1400.

Depends on what all you replace/update while you're doing the work, but you could replace the clutch disc, pressure plate, pilot bearing, pilot seal, shaft and coupler, seals in throw out bearing housing, and throw out bearing with parts from dealer for about $400. Split it and do it yourself and have all the internals of your drive train new.

 

[comfun1]

My tiller sometimes pushes me ahead when in high range, very seldom in low range.

 

[zin01]

So if the service order states the took the "center cover" off that indicates to me they were looking into the range transmission. This is where the shifting part of the pto mechanics are. The only roll pin I can find is external to the case where the pto shift lever is pinned to the shift fork. This roll pin failing only happen if the shift lever has to much force applied to it. You are not by any chance needing to tie the lever or hold it to keep the pto engaged? (I am sure you are not or you would have told us that.)



Just to help us out here. You only talk about high, neutral and low on the pto speeds and the parts diagram shows a mid pto so your tractor must have a hydrostatic transmission. Gear drive B7100s did not have the mid pto.

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