JD Front mount 59" blower

[xkbal]

I'll have to disagree with most posters here. I have a 3720 with the front mount 59 snowblower and use it on a 2600' curved driveway through a forested area.

Couple issues;
1. blower should be a foot wider for the 3720, at least with my snow conditions it would handle it and would be wider than the rear wheels.
2. blower need some sort of shear bolt to protect the impeller. If you're lucky you won't hit anything and cause expensive damage but you shouldn't need to rely on luck with something that costs this much. Check out the links below for some people who've had these issues and some pics of the broken parts (forgot to take pics of mine on the 2 occasions I've broken the impeller mounting universal).

http://www.tractorbynet.com/forums/john-deere-owning-operating/236895-broken-u-joint-59-blower.html
http://www.tractorbynet.com/forums/parts-repairs/193007-uh-oh-snowblower-ate-rock.html

That said I love being able to drive forward while blowing snow, wouldn't give that up (at least for my driveway). Rather than spending that much money for this blower I would evaluate all other front mount blowers the pull type blowers. I know the pull type wouldn't work well for all snow conditions but in my area I'm thinking that's what I should have gone with and leave the loader on over winter.

Al

 

[Rockgod]

I'll have to disagree with most posters here. I have a 3720 with the front mount 59 snowblower and use it on a 2600' curved driveway through a forested area.

Couple issues;
1. blower should be a foot wider for the 3720, at least with my snow conditions it would handle it and would be wider than the rear wheels.
2. blower need some sort of shear bolt to protect the impeller. If you're lucky you won't hit anything and cause expensive damage but you shouldn't need to rely on luck with something that costs this much. Check out the links below for some people who've had these issues and some pics of the broken parts (forgot to take pics of mine on the 2 occasions I've broken the impeller mounting universal).

http://www.tractorbynet.com/forums/john-deere-owning-operating/236895-broken-u-joint-59-blower.html
http://www.tractorbynet.com/forums/parts-repairs/193007-uh-oh-snowblower-ate-rock.html

That said I love being able to drive forward while blowing snow, wouldn't give that up (at least for my driveway). Rather than spending that much money for this blower I would evaluate all other front mount blowers the pull type blowers. I know the pull type wouldn't work well for all snow conditions but in my area I'm thinking that's what I should have gone with and leave the loader on over winter.

Al

I looked at both those threads and the first ones seems to have a point. However, the second one (its damage) seems to have been caused by a bolt that fell out and was used that way for at least 1 season. With that said I thank you for your input/warning.

From the OP in second thread:

Just to try to keep things in perspective, I need to remind myself of two things.

1. I've used the blower for six years and have seen quite a few 4 inch rocks go flying out, or occasionally get jammed, with no breakage, other than shear bolts. I've done the 800 foot driveway many many times with no shearing of bolts at all.

2. In this case, the bolt on the impeller shaft had somehow become lost and the key was the only thing holding the impeller on the shaft. I know this because there was wear on the blower case directly behind the impeller. In fact there was so much wear that two of the four carriage bolt heads there were worn flat and thin. I suspect that the impeller bolt was gone for at least all of this winter so far and maybe part of last winter too. When the bolt is in place, there is a good quarter inch of clearance behind the impeller.

On the other hand, the dealer had three of the hub/U-joint pieces in stock, and when I told him how it had broken, he said "Yeah, that's how they do it."

With luck, I can go another six years

Tom

 

[xkbal]

Different strokes, in 3 seasons I've broken 2 of the same castings (no bolts were missing) and as pointed out by the OP you mentioned he states that it is the failure method acknowledged by his Deere dealer. My dealer stepped up and provided me the second set of parts at no charge after acknowledging that it is a design issue. Should a universal or casting not break I'm not sure what the next weak point in the system is, hopefully not something in the tractor.

If you have a smooth driveway with no chance of something large getting stuck that's fine. In my case, both times there were broken branches blown off the trees in a storm and covered in snow. No way to see them till they had been hit.

You can obviously go with whatever blower you want, just wish someone had warned me.

Al

 

[Rob-D]

I'll have to disagree with most posters here. I have a 3720 with the front mount 59 snowblower and use it on a 2600' curved driveway through a forested area.

Couple issues;
1. blower should be a foot wider for the 3720, at least with my snow conditions it would handle it and would be wider than the rear wheels.
2. blower need some sort of shear bolt to protect the impeller. If you're lucky you won't hit anything and cause expensive damage but you shouldn't need to rely on luck with something that costs this much. Check out the links below for some people who've had these issues and some pics of the broken parts (forgot to take pics of mine on the 2 occasions I've broken the impeller mounting universal).

http://www.tractorbynet.com/forums/john-deere-owning-operating/236895-broken-u-joint-59-blower.html
http://www.tractorbynet.com/forums/parts-repairs/193007-uh-oh-snowblower-ate-rock.html

That said I love being able to drive forward while blowing snow, wouldn't give that up (at least for my driveway). Rather than spending that much money for this blower I would evaluate all other front mount blowers the pull type blowers. I know the pull type wouldn't work well for all snow conditions but in my area I'm thinking that's what I should have gone with and leave the loader on over winter.

Al

Al,
The problem with the 'U' joint breaking is very likely in the set up. When the dealer puts the blower on he should leave out the woodruff key so the bolt acts as a shear bolt. If you have a blower check to see if you have the key in. I put my blower on, not the dealer. I left out any woodruff keys on the input shaft. In fact I talked to my dealer about it and he agreed that the bolt through the U joint should shear if you get a jamb.

I had the 47" blower on my 2720 before I got the 3320 and the set up is different, there is a specific shear bolt on the 47" blower impeller. The engineers at Deere know enough to leave a weak point in the shaft. As far as people saying the bolt breaks to much I never found this, it's never broken and I have a gravel drive. In fact I have dents in my blower from stones! Make sure you don't have a key in your drive, it's simple enough to do.

As far as the size, I've never had a problem with it and also consider this bloewr is used on several tractors, some with less power than the 3 series.

Rob

 

[Rob-D]

Put a grade 2, 1/4-20 bolt in the shaft, it will break before the U joint. This is what I like about Deere, when I had my 2320 the front drive shaft was too small, I had a problem and when I got the new shaft it was thicker. Deere fixed the battery problem too. My 3320 has a sealed battery. Battery acid eating at the front cooler is no longer an issue. If there was a problem they would have addressed it.
Rob

 

[xkbal]

Put a grade 2, 1/4-20 bolt in the shaft, it will break before the U joint. This is what I like about Deere, when I had my 2320 the front drive shaft was too small, I had a problem and when I got the new shaft it was thicker. Deere fixed the battery problem too. My 3320 has a sealed battery. Battery acid eating at the front cooler is no longer an issue. If there was a problem they would have addressed it.
Rob

There is a problem and they have not addressed it. Having an individual dealer suggest something contrary to the products manuals that he thinks should work is acknowledging that he believes there is an issue but it is not Deere addressing a problem. Having Deere put out a technical bulletin saying remove the key and use a grade XX bolt would be addressing it. For a several thousand dollar brand new blower I should not have to be experimenting. Every other blower that they sell (that I'm aware of) has a shear bolt for the impeller, why not this one model?

For what it's worth I also removed the key after the first damage and managed to blow some loose snow for about 100' till I hit a drift and sheared the bolt. While I agree this will protect the universals and tractor you are not able to use the blower to it's potential. That 1/4' bolt is now the shear protection for the whole blower as that provides the power to not only the impeller but also the augers. I considered putting a stronger grade bolt in there but again we are back to whether I should have to experiment on a several thousand dollar blower that was bought brand new from the dealer and is missing a feature that the vast majority of blowers from all manufacturers have.

I like Deere (have operated several over the years), I like the tractor, I like the dealer, but at the end of the day it's a design flaw and there should be a proper shear bolt in the system.

As far as the size of the blower, I don't have a big problem with it. Just if I had known of the issues with the shear bolt and given the price I probably could have gotten one better suited for the size of this tractor that had been properly designed. I went with Deere as I've always had good success with products sold by them. In this case I believe I could have got a better product, for my purposes, for a similar price.

Al

 

[dschuffert]

I think whether you have shear protection or not depends on how old the blower is. I bought a new 59" front mount this summer for my 3520 and then moved it to my 3720. As you can see in the uploaded pictures the driveshaft does have a shear bolt on it. This is where the driveshaft connects to the shaft on the gearbox. The blower itself also comes with four extra shear bolts that are bolted to the body of the blower. The pictures that I uploaded show both.

As a few on this thread I also believe that the John Deere engineers are continually evolving a product line as they get feedback. I have not bee able to use the blower yet, but hope to this winter, then I will be able to better comment on the operation and if I experience any issues with the shear bolt setup.

 

[Rob-D]

There is a problem and they have not addressed it. Having an individual dealer suggest something contrary to the products manuals that he thinks should work is acknowledging that he believes there is an issue but it is not Deere addressing a problem. Having Deere put out a technical bulletin saying remove the key and use a grade XX bolt would be addressing it. For a several thousand dollar brand new blower I should not have to be experimenting. Every other blower that they sell (that I'm aware of) has a shear bolt for the impeller, why not this one model?

For what it's worth I also removed the key after the first damage and managed to blow some loose snow for about 100' till I hit a drift and sheared the bolt. While I agree this will protect the universals and tractor you are not able to use the blower to it's potential. That 1/4' bolt is now the shear protection for the whole blower as that provides the power to not only the impeller but also the augers. I considered putting a stronger grade bolt in there but again we are back to whether I should have to experiment on a several thousand dollar blower that was bought brand new from the dealer and is missing a feature that the vast majority of blowers from all manufacturers have.

I like Deere (have operated several over the years), I like the tractor, I like the dealer, but at the end of the day it's a design flaw and there should be a proper shear bolt in the system.

As far as the size of the blower, I don't have a big problem with it. Just if I had known of the issues with the shear bolt and given the price I probably could have gotten one better suited for the size of this tractor that had been properly designed. I went with Deere as I've always had good success with products sold by them. In this case I believe I could have got a better product, for my purposes, for a similar price.

Al

Did you assemble your blower? Because I did and I followed the instructions AND used the parts Deere supplied. I don't remember seeing a key (I did it a few years ago) and cetainly there is no key on my shaft.
When I approached the dealer about the second stage shearing he agreed with me that the bolt on the U joint IS a shear bolt. So I'm not modding the blower, I'm using Deere's parts and following Deere's instructions. I didn't come up with a grade 2 bolt, again, I used what Deere supplied. I seriously doubt Deere is just looking the other way when these things explode.
I'm sure you can sell your blower for a good price , they are in demand. getting something better is a subjective assessment. You might think you're getting a better blower and find out in the end it's worse.

Rob

 

[Rockgod]

I think whether you have shear protection or not depends on how old the blower is. I bought a new 59" front mount this summer for my 3520 and then moved it to my 3720. As you can see in the uploaded pictures the driveshaft does have a shear bolt on it. This is where the driveshaft connects to the shaft on the gearbox. The blower itself also comes with four extra shear bolts that are bolted to the body of the blower. The pictures that I uploaded show both.

As a few on this thread I also believe that the John Deere engineers are continually evolving a product line as they get feedback. I have not bee able to use the blower yet, but hope to this winter, then I will be able to better comment on the operation and if I experience any issues with the shear bolt setup.

Good photos dschuffert, thanks for those!

By my count that's at least three places for shear bolts on this blower. The other two I noticed were on the main auger itself if I remember correctly. You'd think that'd be enough shear points.

 

[xkbal]

I think you'll find that what you're looking at is not a shear bolt. If the key was not installed, contrary to what the online Deere parts manual shows, then you can experiment with that bolt acting as a shear bolt. I had no luck doing that. The spare shear bolts you refer to are for the auger and have been there for a long time, it's the impeller that is missing protection. If you have a look at your operator manual it will likely only reference the shear bolts on the auger. If it mentions any other shear bolts please let me know and I'll discuss it with my dealer.

Here's the key part number from the manual and attached is the picture from the parts manual showing the driveshaft you mentioned.

20 M84550 Shaft Key 1 (3120, 3320, 3520, 3720 CUT)

 

[xkbal]

Again, I have no issues with however anybody wants to operate this equipment. I even operate some equipment contrary to the way planned by the manufacturer. I just think if you're going to do that you should at least understand what the starting point is. In this case the starting point is that as designed there is shear bolts for the auger. Period. If one wants to experiment that is fine.

My blower was assembled by the dealer according to the Deere manuals. Unless someone can provide some documentation from Deere to prove otherwise. The operations manual only references the auger shear bolts. The parts manual provides the part numbers for the keys to be installed in the universals.

Rob, I expect you missed the key. That is fine if that is how you want to operate the blower but it means you can't get full power to the blower as that 1/4 ' bolt is now the shear bolt for the impeller AND auger. Just because your dealer agrees with you means very little, all the Deere documentation disagrees. The date on the parts manual I looked at online appears to be March 6, 2012 and it still shows the keys I've described. So you are modding the equipment from what information is provided by the manufacturer, unless you think your dealers opinion overides the manufacturers written documentation. I'm more than willing to admit i'm wrong, all I ask is that someone provide documentation (ops manual/ parts manual/technical bulletin). That being said, I've left enough information on the thread for people to make an informed decision so I'm done.

 

[Rob-D]

I think you'll find that what you're looking at is not a shear bolt. If the key was not installed, contrary to what the online Deere parts manual shows, then you can experiment with that bolt acting as a shear bolt. I had no luck doing that. The spare shear bolts you refer to are for the auger and have been there for a long time, it's the impeller that is missing protection. If you have a look at your operator manual it will likely only reference the shear bolts on the auger. If it mentions any other shear bolts please let me know and I'll discuss it with my dealer.

Here's the key part number from the manual and attached is the picture from the parts manual showing the driveshaft you mentioned.

20 M84550 Shaft Key 1 (3120, 3320, 3520, 3720 CUT)

View attachment 286666

OK, I just went out and checked my shaft which is off as I didn't use my blower last year. What I found was indeed a key and a bolt that I had put in a plastic bag and left with the shaft, so I would say there is no specific way to prevent the U joint from breaking if there is a jamb in the shoot impeller. Reading the info with my blower it mentions being careful when crossing a gravel area. I'm wondering if this blower is not intended for gravel driveways. Anyway, I'll have to decide how I will handle the problem as I'd rather not blow up a U joint. What Deere's thinking on this is I have no idea, my 47" blower, as I stated previously, does have shear bolts on both the impeller and the rotor. I do remember that I don't run the blower at PTO speeds until after the driveway is frozen and there is a layer of snow down so that I no longer shoot rocks out the impeller.
Has anyone contacted JD on this? I'd like to know their answer.
Rob

 

[dschuffert]

Thanks xkbal. I learned a lot from this thread. I assembled the unit myself and made a lot of assumptions on what the different bolts were for. I thought the key and bolt that hold the driveshaft to the gearbox were both shear types of material (similar to small engine flywheel or crankshaft shear keys, etc.). You are correct that John Deere lists the key as a "shaft key" and nothing about it having a shear rating. I found Woodruff shear keys all over the internet but not sure what to try yet. I would like to find a Woodruff shear key that fits this application, and shears at a point before the join fatigues, but not sure what the numbers are yet.

 

[Rob-D]

I would try 6061-T6 or 2024 aluminum first. Key material is generally made from lower carbon steels, 1018, etc, you can try leaded steels if the aluminum doesn't hold up to your conditions. If it does fail I would go to a leaded steel, 12L14, 12L15. These are available in small quantities on the net. You can try Speedy Metals, they should have all materials I mentioned.

For the benefit of my friends on TBN I just measured the Rockwell Hardness of the key supplied with my blower. It measures 43 on the Rockwell C scale. This means it is medium hardness, 12L14 (the "L" stands for leaded) for example measures about 14 Rockwell C.

It's probably a good bet to shear before the shaft breaks but I would start with the aluminums I mentioned, that's what I'm going to do. I'd rather change material than shafts!

Hope this helps and thanks for bringing this to our attention. I remember thinking about it at the time I put my blower on and should have researched it further.
Rob

ps: aluminum has been used as a shear material in keys for years. Briggs uses it on their flywheels, any of you who have ever repaired a Briggs engine or other small engine can attest to this.

 

[jjmarotz]

A good idea is to also grease the cables that turn the shoot, they rot out quickly and I've changed them more than once. Grease helps keep them from rotting.
Rob

On the subject of these cables.
http://www.tractorbynet.com/forums/john-deere-owning-operating/232106-59-blower-cables.html

 

[Rob-D]

On the subject of these cables.
http://www.tractorbynet.com/forums/john-deere-owning-operating/232106-59-blower-cables.html

Thanks for the info.
What I've found here is that the salt used on the roads deteriorates the cables prematurely.
Rob

 

[Agent Blue]

I recently purchased a 3 year old 59 snow blower. While making brackets to adapt it to my 4110 I noticed the drive shaft did not have the key in the key way. I thought someone may have forgot to put it in but now it makes sense. Thanks for the info and I won't be replacing something that should not be there. I could not find a 47 and this 59 came up at a reasonable price. The future calls for an upgrade to a 30-40 horse power model and this will transfer.

 

[Rockgod]

Quick update:

Finally arrived yesterday, let it snow!

 

[Rob-D]

Beautiful! You could go commercial with that rig.

 

[Rockgod]

Beautiful! You could go commercial with that rig.

Thanks Rob!

Commercial, I might have to. These types of deals have a way of emptying on the ole bank acc. Thank god for 0% for 60 months.