Bearing replacement on a 47" JD Snowblower

[TheRooster]

Anyone ever replaced the bearings on the drive sprocket shaft (connects to the PTO) on a 47" snow blower? My blower began making more noise than usual this past season, it also began shearing pins between the auger and the impeller. Everything turns freely, but I noticed that I was almost maxed out on the chain tightening, and it just wasn't sitting well on the larger chain sprocket. I thought the shaft the that the drive sprocket was bent (although I don't see how, it's pretty sturdy) because the collars that seat and hold the bearings against the housing are were "wobblying" when I turned it after taking it out of the housing. It's an interesting design in the way the collars "center up" on the bearing to hold it in place, but they are very mobile once you take all six bolts out - kinda wish it was a classic washer/bearing/collar set up, but I'm no JD engineer. The now unbolted, loose collar is what made it look like it was bent.

SO, everything seems to be straight, I've ordered a new chain (both sprockets look fair), but in the event that I have to replace the smaller drive sprocket, I think I have to take at least one bearing off... Are they pressed onto the shaft? There are two spin tight collars with set screws on either side of the sprocket in between the bearings, but I can't see what they're holding, specifically, unless they're just spacers to keep the sprocket in the same place related to the bearings.

I can send a pic if needed, but wanted to get some feedback if anyone had already had to replace that drive sprocket. Thanks in advance for any help/suggestions.

 

[Dutch445]

the collars with set screws are concentric locking collars for the bearings. they are holding the bearing to the shaft, loosen the set screw,
then using a small punch drive the locking collar to loosen it, they aren't too bad to work with.

if you think the sprockets are ok, and since you are going this deep , consider replacing the chain and both sprockets. as well
as the bearings.

 

[TheRooster]

Dutch445, Thanks so much for the response. The exam of the drive sprocket assembly ended up being part of taking it off to get the chain off. I'm going to try a new chain and see if that's the culprit since everything else seems ok. Rather save to $200+ in sprockets unless I need them, although I agree with you, I should replace everything now that I have it apart. It was easy enough to get into, and gives me a chance to clean everything out. I appreciate the info on the collars, it didn't look too complicated, but I couldn't see how the bearings were held on the shaft, I get it now. I have the 54" blade in the meantime, and we haven't hit blizzard season yet, although we're getting a little hammered tonight.

Thanks, again!