Snowblower Help with 3pt Snowblower

[tobypineo]

Hey folks. Need some help with a used 3pt Snowblower that I just bought. It is a 64" Pronovost Puma model, being powered by a B3200 Kubota. It seems to be in very good shape, not a lot of paint is gone, auger and impeller turned fine when I bought it. Problem is that when I hooked it up and turned it on, the shear bolt on the PTO shaft let go.

I figured out that the impeller was hitting the inside of the drum in a spot, maybe 5" long. I don't remember it doing that when I bought it. I figured I would just let her run for a few minutes to wear away the metal, or perhaps bend the metal of the drum enough to give it clearance.

Well, I ran it for about 5 min and it is still doing it. Why would it do that, especially since it turned fine when I bought it? I winched it off the trailer with my atv when I got home, but it was very slow and controlled. I don't know what else to do besides run it. The impeller shaft has no play in it. The spot that rubs is on the bottom of the drum, so I thought maybe it was sagging down, but I don't think so.

On a side note, changing the gear oil in these is no fun! Had to use a suction gun, as there is no drain....I'm sure I didn't get it all out. Oh well, there isn't much to these blowers, hopefully everything will be fine.

I am traveling for a few days, but look forward to the replies you folks always give...thanks for your help.

Toby

 

[ttstpsvernon]

It is never a good idea to let something run in to make clearance or stop banging.This can put undo stress on your pto system and can cost a lot on money in the end specially if there is a vibration involved. It needs to be pulled apart and fixed no matter what it is -- it could be a bad bearing letting the impeller move out of round when spinning fast.

Like i tell my teenage daughter turning up the radio is not a fix for her car.

 

[leonz]

Hey folks. Need some help with a used 3pt Snowblower that I just bought. It is a 64" Pronovost Puma model, being powered by a B3200 Kubota. It seems to be in very good shape, not a lot of paint is gone, auger and impeller turned fine when I bought it. Problem is that when I hooked it up and turned it on, the shear bolt on the PTO shaft let go.

I figured out that the impeller was hitting the inside of the drum in a spot, maybe 5" long. I don't remember it doing that when I bought it. I figured I would just let her run for a few minutes to wear away the metal, or perhaps bend the metal of the drum enough to give it clearance.

Well, I ran it for about 5 min and it is still doing it. Why would it do that, especially since it turned fine when I bought it? I winched it off the trailer with my atv when I got home, but it was very slow and controlled. I don't know what else to do besides run it. The impeller shaft has no play in it. The spot that rubs is on the bottom of the drum, so I thought maybe it was sagging down, but I don't think so.

On a side note, changing the gear oil in these is no fun! Had to use a suction gun, as there is no drain....I'm sure I didn't get it all out. Oh well, there isn't much to these blowers, hopefully everything will be fine.

I am traveling for a few days, but look forward to the replies you folks always give...thanks for your help.

Toby

Hello Toby,

You have the P620 model with the 1 inch wings apparently,

Now you have to remove the impeller from the gear box shaft to determine the damage incurred as the impeller itself is a balanced impeller, Yes it is Balanced!, if the impeller is damaged it will require balancing once again or actual repalcement as the impeller runs at 540 R.P.M. with high thrust loading when casting snow. This is why the rotor is balanced to maintain a proper orbit and to reduce the wear on the bearings and oil seals to an absolute minimum for the end user.

Depending on your skill and ability it may be better to transport the Snow Caster to a nearby Pronovost Implement dealer to facilitate the needed repairs on the snow caster in the shortest possible time.

The simplest repair would be to purchase a new gearbox and replace the old gear box as the damages you are describing fully indicate a failing gearbox.

You need to to take extremely good care of the P.T.0. shaft and clean the female recieving yoke of the PTO shaft that attaches to the male shaft of the snow casters gearbox as well and be sure to wire brush the splines of the shaft stub to aid in attaching the P.T.O. shaft


Depending on your ability you would need to purchase nylock nuts and new washers for the gear box retaining bolts which attach it to the snow casters weldment that supports the gear box which is attached to rear of the impeller drum as well as new set screws/bolts/nylock nuts/shear pins for the new impeller shaft protruding from the new gearbox and some blue Loctite for the snow caster where needed.

You cannot afford to run the snow caster in its current condition as is scraping the impeller drum and will lead to a much more expensive failure.
_________________________________________________________________
Pronovost or not at all!!!:thumbsup::licking::drool:

 

[GPintheMitten]

Does each impeller wing hit the drum or just 1 or 2?

If all 3 rub to the same extent, then the shafts and bearings may be ok.

On the very used blower I bought all 3 rubbed very little. I used an angle grinder to remove about 1/16 inch from each. I took the chute off and was able to access them from the chute opening at the top of the drum.

There is no wobble on mine.

I agree however that the bearings and shaft must be straight and the fan needs to be balanced.

 

[bubbacuse77]

any chance your PTO is too long and you are pushing against the blower when you lower or raise the 3pt? My friend had this problem last year and damaged his PTO shaft internally on his NH Boomer. Cost him a pretty penny to fix and guess who was over blowing his driveway while his was in the shop?

 

[tobypineo]

Geez, you guys are talking about some pretty major repairs! I'm wondering why all was well when I looked at the blower, I could turn it by hand easily...The PTO being too long is something I will look into.

 

[GPintheMitten]

Geez, you guys are talking about some pretty major repairs! I'm wondering why all was well when I looked at the blower, I could turn it by hand easily...The PTO being too long is something I will look into.

I'm not. Did you check out what I suggested? You may have just dinged the drum sheet metal. My fix took about 10 minutes.

 

[Jerry/MT]

Hey folks. Need some help with a used 3pt Snowblower that I just bought. It is a 64" Pronovost Puma model, being powered by a B3200 Kubota. It seems to be in very good shape, not a lot of paint is gone, auger and impeller turned fine when I bought it. Problem is that when I hooked it up and turned it on, the shear bolt on the PTO shaft let go.

I figured out that the impeller was hitting the inside of the drum in a spot, maybe 5" long. I don't remember it doing that when I bought it. I figured I would just let her run for a few minutes to wear away the metal, or perhaps bend the metal of the drum enough to give it clearance.

Well, I ran it for about 5 min and it is still doing it. Why would it do that, especially since it turned fine when I bought it? I winched it off the trailer with my atv when I got home, but it was very slow and controlled. I don't know what else to do besides run it. The impeller shaft has no play in it. The spot that rubs is on the bottom of the drum, so I thought maybe it was sagging down, but I don't think so.

On a side note, changing the gear oil in these is no fun! Had to use a suction gun, as there is no drain....I'm sure I didn't get it all out. Oh well, there isn't much to these blowers, hopefully everything will be fine.

I am traveling for a few days, but look forward to the replies you folks always give...thanks for your help.

Toby

There are a few things I would check.

Make sure that whatever is used to retain the impeller is tightened to spec. The impeller should be keyed to the gearbox output shaft and retained by a bolt that holds it on the shaft. If the bolt is tight, loosen it and make sure the key isn't sheared.

Make sure that whatever holds the gear box in the frame is tightened per spec.

If the first items are good, check the impellers radial run out. Try to lift it up and down and left to right. Use a bar to pry it if you can't get to it any other way. If you find a a lot of runout, then the bearings maybe damaged, Check with the manufacturer to find out the allowable runout.

If the runout is good, then the impeller housing isn't concentric to the impeller shaft, indicating some sort of damage to the support frame for the gearbox or a bent output shaft. try to put a dial indicator on the edge of the impeller through the impeller housing exit to the chute and rotate the impeller to see if there is a bent shaft. If the shaft isn't bent then the impeller housing is bent due to some structural damage to the frame, or the gear box support stucture is bent.

 

[tobypineo]

Hey folks, I'm actually in Helsinki on business right now, so I haven't had a chance to look into your recommendations. But I do appreciate them, and will be looking into them when I get back in about a week. Keep any other ideas coming! I am intrigued at this point with the bent drum idea and the long pto shaft idea, there just wasn't enough opportunity to do damage during transport after I bought the thing, I don't see how anyway....thanks for the replies thus far...Toby

 

[rambler]

There are a few things I would check.

Make sure that whatever is used to retain the impeller is tightened to spec. The impeller should be keyed to the gearbox output shaft and retained by a bolt that holds it on the shaft. If the bolt is tight, loosen it and make sure the key isn't sheared.

Make sure that whatever holds the gear box in the frame is tightened per spec.

If the first items are good, check the impellers radial run out. Try to lift it up and down and left to right. Use a bar to pry it if you can't get to it any other way. If you find a a lot of runout, then the bearings maybe damaged, Check with the manufacturer to find out the allowable runout.

If the runout is good, then the impeller housing isn't concentric to the impeller shaft, indicating some sort of damage to the support frame for the gearbox or a bent output shaft. try to put a dial indicator on the edge of the impeller through the impeller housing exit to the chute and rotate the impeller to see if there is a bent shaft. If the shaft isn't bent then the impeller housing is bent due to some structural damage to the frame, or the gear box support stucture is bent.

Very good checklist. Only other thing is the bottom of the blower got dented while being unloaded, the bottom tin under the fan came up a bit? Otherwise has to be one of these things.

A too long pto shaft will bend something somewhere, either inside your tractor, or on the blower - those are covered in this checklist too, bent/broken frame or gearbox mount...

--->Paul