Mowing B3030 rear PTO slipping

[Granite Tractor]

I've had my B3030HSDCC for about 7 years now (about 325 hours). This summer I've noticed that my rear PTO is starting to slip/stall when I'm using my brush-mower in high grass (there is no loss of engine RPM on the tractor when this happens).

I've read about PTO clutches on some tractors and looked at my service manual, but I can't tell if this model has a rear clutch.

Any assistance greatly appreciated.

Thanks.

 

[diesel85]

I doubt the clutch is slipping on the tractor. Did you check the slip clutch on your PTO shaft itself?

 

[Granite Tractor]

I doubt the clutch is slipping on the tractor. Did you check the slip clutch on your PTO shaft itself?

Thanks for the quick reply. Slip clutch would be great (since that's easy to fix), but in my case the entire drive shaft is slowing down - which suggests something internal (and perhaps $$$)?

 

[diesel85]

Have you checked the fluid level?

Yes, they do have clutches for the PTO output.

KPN: 6A700-13750 DESC: DISK,CLUTCH QTY 5
KPN: 6A700-13762 DESC: PLATE(CLUTCH,1.2) QTY 4

 

[Granite Tractor]

Thanks for the part numbers! Yes, fluid was first thing I checked.

I must admit I ran the brush mower for a few years without properly servicing the slip clutch. Looks like I'm paying for that...

Does Kubota sell separate service and repair manuals? I have the service manual but it just shows basic adjustments.

 

[diesel85]

Yes, Kubota sells what's called a Workshop Service Manual (WSM for short):

For a B3030: KPN: 97897-13290 DESC: Kubota: B2630/B3030 Shop Manual QTY 1

This is what any Kubota shop will have either in microfiche, paper, or digital to work on this series tractor as per factory specification.

 

[JWR]

Thanks for the quick reply. Slip clutch would be great (since that's easy to fix), but in my case the entire drive shaft is slowing down - which suggests something internal (and perhaps $$$)?

That is a critical answer you just gave. IF in fact the whole drive shaft slows down while engine RPM remain fairly constant then you have PTO clutch slippage, not slip-clutch slippage. diesel85 was well justified saying he doubted that because PTO clutch slippage is so rare. I have never seen a tractor with that issue though obviously it can happen. If this persists I'm afraid you are in for a $$$ repair. One way to confirm the problem is to locate a shop with a PTO dynamometer. Go hook your 3030 to the dyno and see what you get. If it puts out around 90% of your rated engine hp or 100% of your rated PTO output hp and show no signs of slowing down, then you DO NOT have a PTO clutch problem. If it puts out well below rated PTO output hp and worse yet varies and drops, you are in for an expensive repair.

 

[Granite Tractor]

Bummer. How expensive are we talking here? I'm now remembering that I had a spreader I was using to sand my driveway that was getting jammed by rocks - not sure that would be enough to do damage. I also had some work done to the PTO shifter under warranty (the pto selector would not engage the rear PTO) - not sure if that could be related

 

[JWR]

I'm not saying that those things you mention ARE related but they certainly could be. To be honest it seems likely. I don't have a feel for costs but the work would involve taking the tractor apart enough to get at the PTO clutch. Labor doing that has to be in the hundreds. But first, before believing any disasters, I recommend you run enough tests to find out where the problem is.

 

[moship]

Here's the exploded view in the event it helps your understanding.