Snow BX2750 Snowblower Shear pin, rebuild

[McKeanSeven]

Good Morning
I have read a number of posts on this subject. Excessive Shear pin breakage. I have owned this blower for several years and the breaking to shear pins,,,,,,,, primarily the fan shear pin has gotten worse, even to a point where a pin will break in after 50 yards of very light snow. The blower vibrates more and more and I have determined that something is bent, mis-aligned, worn, etc. I have taken the chain sprockets/gear assembly apart and repaired a few set screws and such but with little improvement. I plan to do a rebuild on the unit this spring and I am asking if any one can give me some pointers on what to look for and what should be replaced. I will obviously replace the bearings, but are there other items that should be of particular concern, or areas/items that wear/fail on these units. Any help is greatly appreciated.
Regards
c

 

[davesl708]

If the unit is shearing pins routinely be sure and inspect the hub where the pins go. The holes may be getting enlarged from the shearing force. The larger holes will allow a greater impact on the shear pins causing more frequent shears. Also, loose bolts will enlarge the hole and increase the impact in that area.

Good luck with the rebuild. Snow blowers earn their keep.

 

[McKeanSeven]

Thanks for your reply. The Pin Hole has definitely been disrupted. When I move the fan forward during pin replacement the pin hole has been burred around the edge. Sounds like a new drive shaft from the worm gearbox is in order for replacement.
Regards
c

 

[Kanook]

Not saying that this is your reason for excessive shear bolt usage... A few years back I was going through shear bolts without good reason and found out that the blower I had at that time required a 1/4in bolt and I was using 3/16in and was also torqueing the bolts too tight. Was told the ny-loc nuts should only be snug.

 

[McKeanSeven]

Not saying that this is your reason for excessive shear bolt usage... A few years back I was going through shear bolts without good reason and found out that the blower I had at that time required a 1/4in bolt and I was using 3/16in and was also torqueing the bolts too tight. Was told the ny-loc nuts should only be snug.

I actually have a BX 2750D and I understand the fan bolt is the same size as the auger bolt 2 1/4" X 5/16.
I bought several 1/4" by 1 1/4" per the manual and they were obviously not long enough to pass through the fan and shaft assembly...........but with that being said I might be torqueing too tight....... People say Grade 8 on the fan the Grade five for the augers..........I did have a few problems with auger bolts but have not broken an auger bolt for quite some time, but there is definitely something out of wack on the fan assembly.

 

[SeymourBota]

I recently had an issue with the pto shaft right behing the lower chain sprocket- where clearances are tight.

When I previously needed to replace bearings, etc. and chain, I discovered you can buy the whole section as an assembly- getting everything new and machined together for much less than the cost of individual parts.

On the fan shear pins, are you using the grade 8 replacements?? If not, they will definitely shear in a few yards.

 

[McKeanSeven]

That PTO assembly behind the lower sprocket does seen like a weak link with a fair amt of vibration. This one-piece assembly, is it a Kubota part ordered through them,,,,,,,, or something after-market. Do you have the part #??

I just moved up to a grade 8 on the fan bolt,,,,,,, and it definitely helps but will still pop a bolt periodically. Thanks for the advice.
Regards
c

 

[SLIMSHADIE]

Grade 8 on fan and grade 5 on augers per manual.

 

[SeymourBota]

That PTO assembly behind the lower sprocket does seen like a weak link with a fair amt of vibration. This one-piece assembly, is it a Kubota part ordered through them,,,,,,,, or something after-market. Do you have the part #??

I just moved up to a grade 8 on the fan bolt,,,,,,, and it definitely helps but will still pop a bolt periodically. Thanks for the advice.
Regards
c

Mine is an early generation BX2750 and the assembly is 70001-00696 Cost $192.20

There is a pin through the driveline right behind the sprocket on the new assembly and it has now sheared.