Snowblower Need to increase PTO speed to use a Kubota B/L 2563 snowblower on a 540 PTO?

Crocus · Feb 15, 2017

I purchased a used "Kubota" B/L2563 snowblower to use on the 3pt hitch on my Kubota B26TLB (540 PTO). I tried it only once with deep wet snow and the chute jammed with hard packed snow before I moved little more than a foot. After examining the parts diagrams for it and reading any relevant posts it looks like it was designed for a two speed PTO as on a Kubota L2250 to be run at 1000RPM. That blower can be front-mounted with different frame etc but the drive shaft runs straight to the impeller/auger for both types of mounting.
I can't easily increase the impeller diameter and modify the auger gear ration so I wonder if there is a gearbox somewhere in the world that could be bolted/welded at the drive input on the blower to double the RPM?
I also wonder if I welded on more blades onto the impeller or enlarged each blade as much as possible, would that work? The auger would still be turning too slow but it could produce a usable attachment. Otherwise it is a $1000 boat anchor.
Comments please. I already know I was a "dumb ***" for not researching more before buying.

PHPaul · Feb 15, 2017

I'm guessing increasing the PTO RPM is the only viable solution.

A speed doubler is easy, but a speed doubler that doesn't reverse rotation is a bit of a different story. They're out there, but they won't be cheap. Also be sure whatever you get is rated for the HP.

The other issue is that the speed doubling gearbox is going to take up room. At the very least you'll need a shorter PTO shaft, and I wouldn't be surprised but what you'll need to modify the mount to move the blower back further from the tractor so you'll have enough room without running into joint angle issues on the shaft.

Long term, you might be better off to sell the blower to someone with a 1000 RPM PTO or willing to front mount it and use the proceeds to buy a 540 blower.

JCByrd24 · Feb 15, 2017

I agree it looks like you are correct about the PTO speed. This unit looks similar in size to a front mount blower that runs higher fans speeds than rears which are larger and use the 540rpm PTO. These units are very common these days and a common solution exists, though opposite of yours. Most current mid PTOs spin around 2000-2500 RPM and thus almost all current front blowers have a chain drive gear reduction on them to drop it down to around 1000RPM. You need just the opposite, but the parts are the same. A couple bearings, sprockets, and chain and a little bit of fab and you can make this work. The chain drive will not reverse the rotation. I'd google image search the common JD 47" quick hitch blower and you will be on your way. It's a bolt on affair for them. In fact I have the whole chain drive setup from JD that I could send you as I just mounted a JD snowblower custom on the front of my old Yanmar, which has 1000 RPM PTO in addition to the 540 so I removed the chain reduction. JD had QC issues on their sprockets and undersized the chain in my opinion so I think you'd be better off starting from scratch with common surplus center parts instead of JD brand.

aczlan · Feb 15, 2017

This was originally a front mount blower, correct? If so, look on the back of your snowblower. If it's like most of their RAD snowblowers that Kubota is using, the incoming PTO shaft goes through two sprockets, one drives the other by a chain and that reduces the speed of the fan in relation to the PTO shaft.
If you were to remove that set of sprockets, you could then connect your PTO shaft directly to the input shaft on the impeller fan and you should be good to go because that speed reducer reduces the impeller speed to around 540 RPMs.

Aaron Z

Crocus · Feb 16, 2017

Thanks all
Looks like the sensible solution would be to sell it and buy a correctly geared blower. Selling it might be tough because it is an old machine and I doubt the frame mechanism is available to mount it on the front. The parts diagram also shows a second driveshaft is required in addition to the one I have. I'll have to hope for a buyer with a high speed rear PTO.
By the way it doesn't have a chain drive, only a single gearbox. The impeller is a direct drive and the auger is driven through the gearbox.
I must compliment Kubota for having a parts diagrams for that old unit available on their website. Otherwise I would have never figured out how it was intended to be used.

JCByrd24 · Feb 16, 2017

Yes any current rear mount should be designed to run on 540rpm with a larger fan. I see these used on CL pretty regularly. I believe 1000RPM PTO is not completely a rarity in older machines so you might not have too much trouble selling the one you have. That being said, it's really not much of a job to add a reduction chain drive to the unit you have. If you were close by I'd help you do it....here's an example stolen from another thread. Again this is a speed reduction but the principle is the same:

http://www.tractorbynet.com/forums/files/kubota-owning-operating/497104d1485846429-going-through-second-stage-bolts-20170130_210935-jpg

buickanddeere · Feb 17, 2017

How far is the red line past the rated pro rpm ?

Crocus · Feb 17, 2017

Thanks again JCByrd24. I like that idea. I'll look into fabricating a "speeder-upper" version of that example. Thanks for the offer of help but I am a long way from Maine and the tractor is another 500km farther west.

aczlan · Feb 17, 2017

Do you have the manual which says it that this is supposed to be a thousand RPM input snowblower? From what I see looking at the exploded parts diagrams on the Kubota site, the three point hitch versions are all intended to have a 540 RPM PTO. The front mount ones all have the chain and sprocket drive to slow them down so they can run off of a 2000 rpm front PTO and still have the fan running at around 540 RPMs.

Aaron Z

Crocus · Sep 19, 2017

aczlan said:
Do you have the manual which says it that this is supposed to be a thousand RPM input snowblower? From what I see looking at the exploded parts diagrams on the Kubota site, the three point hitch versions are all intended to have a 540 RPM PTO. The front mount ones all have the chain and sprocket drive to slow them down so they can run off of a 2000 rpm front PTO and still have the fan running at around 540 RPMs.

Aaron Z

With winter around the corner I have revived this thread to decide how to solve this challenge.
That blower is designed for Kubota tractors L2250, L2550 and L2850. They all have 540 and 1000RPM PTO's and can have a mid-mount PTO at 1080 or 2000RPM The drive shaft on the blower fit my 540RPM output shaft even though it should be different if it is designed to be run at 1000RPM. On another Tractorbynet thread I read that the blower driveshaft should couple to a 21 spline PTO shaft for 1000RPM instead of the 6 on the 540 shaft.
I have ordered a manual for that blower to sort this out.