BX2750A Worm Gearbox Repair; can't remove locking collar

Timberline · Apr 24, 2018

Back in mid-March, after a 20" snow, I began blowing our drive. Got about 200' into the first pass and discovered the fan was working, but the augers had stopped and all shear bolts were still intact which made me assume there was some kind of failure in the worm gearbox.

Yesterday, I finally got around to tearing it apart and have gotten everything unbolted and am now down to the locking collar on the fan drive shaft. I removed the set screw and have attempted to loosen the collar by tapping the unthreaded hole in a clockwise direction since the shaft turns counter clockwise.
So far to no avail. What I have noticed is that the collar appears to be crooked with the face of the collar not being parallel to the face of the bearing. See attached pic.

Any thoughts on how to get this off would be welcome.

North Idaho Wolfman · Apr 24, 2018

2 pipe wrenches on on the collar one on the shaft.

kubotasam · Apr 24, 2018

I would avoid using a pipe wrench on the shaft. If the pipe wrench puts any marks on the shaft you will have a hard time pulling the shaft through the bearing after you get the collar off. I would suggest blocking the fan from moving by wedging a 2x4 down through the chute.

D2Cat · Apr 24, 2018

I'd pound the collar counter-clockwise.

Yooper · Apr 24, 2018

Sometimes those collars have two set screws 90 degrees apart.

North Idaho Wolfman · Apr 24, 2018

kubotasam said:
I would avoid using a pipe wrench on the shaft. If the pipe wrench puts any marks on the shaft you will have a hard time pulling the shaft through the bearing after you get the collar off. I would suggest blocking the fan from moving by wedging a 2x4 down through the chute.

Yea your right, I didn't word that well.
I was thinking on an area of the shaft that does not require the bearing to slide over it.

And like D2 said, yes the collar can be set either direction regardless of the shaft rotation.

kubotasam · Apr 25, 2018

Going by your pict in the first post it looks like you have the nuts removed from the bearing retainer plates. You should be able to push the shaft with the fan and gearbox towards the front and work it out of the housing. Once removed then it should be easy to get that collar off. Also if the bearing is stuck (rusted) to the shaft you can then center drill the end of the shaft and use a gear puller to remove the bearing.

kubotasam · Apr 25, 2018

Thinking this through I am not sure that is how I did it. It was a few years ago and perhaps I did not recall correctly. I think what I did was to loosen the fan on the shaft by removing the bolt that holds the shear pin collar to the shaft. that allowed the bearing to push through the back of the housing. Then drilled the end of the shaft (to keep the puller from sliding off), put on the gear puller and removed the bearing.

Timberline · Apr 26, 2018

kubotasam said:
I would avoid using a pipe wrench on the shaft. If the pipe wrench puts any marks on the shaft you will have a hard time pulling the shaft through the bearing after you get the collar off. I would suggest blocking the fan from moving by wedging a 2x4 down through the chute.

I tried this using one pipe wrench on the collar and the other on the shaft between the gearbox and the fan shear plate. Two complete turns in both directions and still totally tight. Next?

Timberline · Apr 26, 2018

kubotasam said:
Going by your pict in the first post it looks like you have the nuts removed from the bearing retainer plates. You should be able to push the shaft with the fan and gearbox towards the front and work it out of the housing. Once removed then it should be easy to get that collar off. Also if the bearing is stuck (rusted) to the shaft you can then center drill the end of the shaft and use a gear puller to remove the bearing.

Though one side of the flange can be easily removed, the other side is outboard of the blower housing and can't be pulled through with the bearing in place.

rentthis · Apr 26, 2018

I recently took one off with a band saw. They come with the new bearing. Looks like it would be to hard to get to on yours though. Maybe an angle grinder with a thin cutting disc.

Timberline · Apr 27, 2018

I got it off. I don't have an angle grinder, but I used my Dremel with a tungsten carbide cutting bit. It was slow going, but I used the set screw hole and the dimple for setting the collar, to reduce the amount of metal I had to cut through. Once off, I was able to pull the bearing by hand with a bit of WD-40.

Now I get to tear apart the worm gearbox and see what kind of surprise I have in there.

Timberline · Apr 30, 2018

Turned out to be a broken spring pin connecting the worm gear to the shaft. No other damage found.

tinkerwitheverything · Apr 30, 2018

Timberline said:
Turned out to be a broken spring pin connecting the worm gear to the shaft. No other damage found.

Thats good you have it figured out. Thats kinda weird that they would use a spring pin. to hold the worm to the shaft. Wonder how long a new one will last. Almost seems like it's going to be like a shear pin inside the case.

07wingnut · Apr 30, 2018

Well, you lucked out with that one. On mine, the shaft was sheared off just inside the gearbox.

Timberline · May 3, 2018

tinkerwitheverything said:
Thats good you have it figured out. Thats kinda weird that they would use a spring pin. to hold the worm to the shaft. Wonder how long a new one will last. Almost seems like it's going to be like a shear pin inside the case.

It lasted 14 years, but ultimately was probably cause by an incident in 2010 when I hit a rock big enough to twist the RH auger about 30º and bend one of the fan blades enough to instantly jam it. None of the shear bolts broke, but it snapped the spring pin on the small chain gear off the PTO. This may have been a common problem since that small gear was re-designed to be welded to the shaft rather than pinned.

Search

BX2750A Worm Gearbox Repair; can't remove locking collar

Timberline

New member

Attachments

North Idaho Wolfman

Moderator

kubotasam

Well-known member

D2Cat

Well-known member

Yooper

Well-known member

North Idaho Wolfman

Moderator

kubotasam

Well-known member

kubotasam

Well-known member

Timberline

New member

Timberline

New member

rentthis

Member

Timberline

New member

Timberline

New member

tinkerwitheverything

Active member

07wingnut

Active member

Attachments

Timberline

New member