bearings keep breaking
 

I am wondering and hoping that someone can can help me determine why the bearings keep breaking. They are the bearings on the jackshaft (I think that is what it is called) on the small sprocket side. I have another new bearing but I am reluctant to use it until I can figure out what might be causing it. Any ideas? Thank you in advance!

Hello;
Was just reading your "new to the forum thread." One of the best things you can do is take pictures and post them using the blue "Post Reply" button or "Go Advanced" button. At the bottom of the page will be a "manage attachments" button that will let you upload pictures to your post-- they likely will need to be re-sized prior to uploading. All that said, what part of the bearing is breaking? If it is the inner race, the damage on the shaft may be may be causing that to happen if you have to force the bearing on. It may be spreading the bearing and cracking the race. You also mentioned missing teeth on the sprocket. Time for a replacement.

Thank you X-bird. It is indeed the inner race (I think). Lol. It is the part that rides on the shaft that keeps breaking. The outer stays intact. I will post a picture of the way I have the sprocket mounted and a picture of the shaft. I am not sure what other pictures might be helpful. The grooves mentioned are not highly visible and the ones that prevented the bearings from sliding on were super minor; you could barely feel them.

Thanks again for your advise. I've already learned something new. I'd never even heard of an outer or inner race before. :-)

The hardened metal used in bearings is much like tempered glass, very strong yet it has it's weaknesses. Just like the glass will shatter if lightly tapped on its edge with a hard object, hardened metal can break easily if forced the wrong way--in this case spread out a little bit. It doesn't take much. If you can't get the bearing on by hand, there's an issue with either the bearing size or the shaft--which is likely the problem.

OH poop! I bet I broke it on the install. The bearing I got is the exact same bearing on the other end. Same size. Are both sets of bearings usually the same size? Perhaps forcing the bearings on the shaft weaken it but I bet I broke it when tapped the bearings with a hammer. I didn't realize they were so fragile. The bearing did not fit well into the bore either. I covered it with a folded rag and tapped it in with a hammer. Sounds like I probably killed it with my hammer!?!? That right? Man I have a lot to learn.
I have to go bend some steering parts back to straight. Kids crashed it. I was going to lightly heat it with a torch and then squeeze it in a vise. Is this idea okay? Since icm new, I gotta ask. Lol. Thanks again for your advise X-bird.

X-bird, (or anyone) do you suppose tapping the bearings is what caused them to break so quick?

actually, if you have toe force it on, the spread is probably the cause. Clean the axle along the entire length the bearing has to slide down to get to position. same thing if it has to go inside something. Clean it up with a red scotchbrite pad or automotive wet/dry sandpaper.

Will do "x" thank you. I sanded the shaft until the bearing slid on. I figure the forcing probaby occured when I was just trying to see if it would fit yet between sandings. I will clean everything and install the new bearings and see how it goes. If they break again, i'll post pictures of everything. Thanks again.
Danny

Zapper
 

No the shaft will need cleaning with fine sand paper.If he just tapped it on he has another problem.