BX2750D Snowblower Wormgear repair Help

[Southernfarm]

Hi all,

Well, it turns out that the PO of my unit, who went through many shear bolts on a river rock driveway did a big no-no. And worse yet, I should have checked before the start of the snowblowing season. Yes, he used standard Grade 5 bolts for all 3 shear pins!

So I hit my first hidden obstacle and I when I did, I quickly reached for the PTO and disengaged it. Removed the obstacle and started up. No auger. So I checked the shear pins and they are regular bolts.

Here is what I found. The second stage impeller, turns with the PTO and is engaged. That shaft goes into the worm gear and turns. But nothing out on the worm gear onto the main first stage auger. Both left and right augers are connected together with the auger shaft, but the auger shaft spins inside the gearbox.

So I need help with steps to remove the gearbox and find out what broke inside. Could be a worm gear, but I don't think so, because it it was, only a couple of teeth snapped off, I wouldn't be able to spin the auger all the way around. The parts diagram shows a woodruff key on the axle. Would it be possible for that to shear off and everything else be OK? Or would the axle or worm gear need to be replaced? Can I just disassemble the gearbox halves in place, or do I have to remove it from the blower first? Which would mean, disassembling drive shaft right from the chain drive, and forward from that wouldn't it? If it makes a difference, this is the BX2750D from 2013-2014 era.

 

[kubotasam]

I have removed the gearbox on B2650 and B2660 snowblowers. Both look very similar to yours for the parts breakdown. It is fairly easy. You are correct. You need to start with the chain drive reduction. Once that is out of the way you will see the locking collar on the rear bearing, loosen the set screw, twist the collar and remove it. Now go to the other side. Remove the shear pin holding the impeller to the shaft. Remove the bolts from the bearings at the ends of the auger shaft. Remove the support piece from the center that connects the gearbox to the housing. With a little luck and wiggling the gearbox, augers and shaft will pull out as a unit. The impeller stays in the housing.
Now you should be able to remove the augers and auger shaft. Then you can open the gearbox and find out what is wrong.

 

[kupitz]

Hopefully you don't need a complete gearbox, I paid $700 last year after mine blew up. I think the root cause was snow build up on top "wicked" into the breather port and after a few hours....KABOOM!

 

[NoJacketRequired]

Oh man that's ugly, kupitz. What a terrible feeling you must have had when you first saw that mess.

 

[kupitz]

Oh man that's ugly, kupitz. What a terrible feeling you must have had when you first saw that mess.

Especially considering 14" of snow on the ground and I only got partway through my first pass on my 1/4 mile drive!

 

[Southernfarm]

At least I mostly finished my blowing when it happened. It is going to be around -40 degrees tonight so not going to be working on it. In a couple of days it is going to warm up to near 0 degrees Celsius so I will do the teardown then.

 

[Southernfarm]

Thanks for the confirmation on the removal steps. Just one follow up, can the woodruff key shear off clean? I tried moving the auger and impeller and cannot get both shafts to engage with each other, so I have either sheared off all the teeth on the worm gear or just the key is sheared. Question becomes how much damage is on the axle and / or worm gear if I just sheared the key.

 

[kubotasam]

Thanks for the confirmation on the removal steps. Just one follow up, can the woodruff key shear off clean? I tried moving the auger and impeller and cannot get both shafts to engage with each other, so I have either sheared off all the teeth on the worm gear or just the key is sheared. Question becomes how much damage is on the axle and / or worm gear if I just sheared the key.

The parts diagram shows a spring pin part # 13 holding the worm gear to the impeller shaft. It could be that the spring pin has sheared. That would be a cheap fix.

 

[D2Cat]

"spring pin", is that a Kubota/oriential term? I always referred to THEM as a roll pin.

 

[Southernfarm]

I thought of the roll pin too, but I can manually turn the auger shaft and I don't think I could if it were to be the roll pin. Just by the way a worm gear works.

Sent from my Z850 using Tapatalk

 

[kubotasam]

I thought of the roll pin too, but I can manually turn the auger shaft and I don't think I could if it were to be the roll pin. Just by the way a worm gear works.

Sent from my Z850 using Tapatalk

Some worm gear drives will not turn from the other gear(not sure of the correct term) . However at least my 2 blowers B2660 & B2650 will. I spin the augers and the impeller turns. The B2551 I just sold would spin the impeller by turning the augers also.

 

[Toyboy]

I think I've heard of them called "split pins" too, but I believe roll pin is correct

 

[kupitz]

Is that large gear made from some type of aluminum alloy, I have a similar gear drive on my snowblower and the gear is made of brass.

No, it's brass, had a few ounces of nice shaved brass after the explosion.

 

[OrangeLivin]

Holy crap is that ugly - sorry for your misfortune kupitz! Did you do the rebuild yourself? $700 sheesh Did they plate it in gold??

Where is the breather port that possibly got compromised? Does it sit right on top where snow builds up?

 

[kupitz]

Holy crap is that ugly - sorry for your misfortune kupitz! Did you do the rebuild yourself? $700 sheesh Did they plate it in gold??

Where is the breather port that possibly got compromised? Does it sit right on top where snow builds up?

Yes, it was ugly! I did it myself, $700 was the new gearbox and all new bearings on the auger since I had it apart. Took a few hours start to finish, not bad. The breather sits right on top where the snow builds up as you mentioned. I never did find that, only a couple of chunks of the cast aluminum housing.

 

[Southernfarm]

Well bad news not the roll pin or spring pin and not the woodruff key. It's the brass gear.

Sent from my Z850 using Tapatalk

 

[Southernfarm]

Messicks price for complete gearbox and shafts is $473 USD and will call dealer tomorrow for local. The may also have just the gears but no longer made.

Sent from my Z850 using Tapatalk

 

[Southernfarm]

I definitely will give Rob a call. I will tear it down further and see if anything else is damaged.

Sent from my Z850 using Tapatalk

 

[Southernfarm]

I did copy the info. Perhaps a mod could edit or Hudson could edit out the contact info to prevent spamming to Rob.

Sent from my Z850 using Tapatalk

 

[Southernfarm]

I suspect they shouldn't actually break if you use the correct shear pins! I sent an email to the previous owner with a photo as an FYI. He is a nice guy too and rebuilds alternators. He may be able to help cover the machining cost too.

Sent from my Z850 using Tapatalk