Rotor nut advice

[-Adam]

Hello!

I recently borrowed my neighbor's 150 the pull start jammed. Turns out the needle bearing in the rotor nut went bad.  The one I purchased came with the nut and bearing separated and it's a super-tight fit to mate them together; I can barely get the bearing started in the nut!  I assume a lot of people probably break out the rubber mallet and go to town, but I don't want to risk damaging the bearing.  And, I assume this is the wrong application for a lubricant.  I thought about heating the nut to expand it, but don't know if that much heat would damage the bearing.

So, anyone have any experience with this?  Any ideas on the best way to get the bearing into the nut?

Thanks much!

-Adam

[-Adam]

Jul 12, 2021 13:17:23 GMT -5 -Adam said:

Hello!

I recently borrowed my neighbor's 150 the pull start jammed. Turns out the needle bearing in the rotor nut went bad.  The one I purchased came with the nut and bearing separated and it's a super-tight fit to mate them together; I can barely get the bearing started in the nut!  I assume a lot of people probably break out the rubber mallet and go to town, but I don't want to risk damaging the bearing.  And, I assume this is the wrong application for a lubricant.  I thought about heating the nut to expand it, but don't know if that much heat would damage the bearing.

So, anyone have any experience with this?  Any ideas on the best way to get the bearing into the nut?

Thanks much!

-Adam

Sorry, the text "Homelite 150 Nut Rotor" was supposed to be an image.  Let me try here.

[blythkd]

Never heard of or seen those parts separate. I installed a few back in the day but they were always an assembly through Homelite service parts.

And no, don't beat on it. Definitely should be pressed together, a vise should do the trick. That bearing will only grab in one direction and has to freewheel in the other direction so it can let loose when the engine starts and runs. So check it before you press it in. I'm guessing once it's in, it's in, no coming back out.

If I "lubricated" it with anything, it would be Loctite. If you do Loctite it, just put it on the outside of the bearing, not down in the nut, so it doesn't pool up excess compound in the bottom of the nut and end up in the bearing. That's a blind hole, if I recall correctly.

[sweepleader]

Heating the nut to 250*F would be fine, bearings take that all the time so they can slip fit and shrink in place. I have a toaster oven I use, just set it at 250 and leave the nut in there for a half hour. Then pull it out and work quickly, should drop in but I would have a vise handy so I could push it snug using something flat on the rough vice jaw. Too much push and the bearing will break.

[blythkd]

Yeah you could heat the nut even hotter than that. I just wasn't sure if the lining of the bearing might have some nylon or something similar involved. I went and looked for a nut but I don't have one. But 250 would probably be ok regardless of what's inside the bearing.

[adam]

Thanks to you all for your advice (I posted this question as a guest "-Adam")!  These suggestions make perfect sense.

It seems *way* too tight to use a vice only, so I will heat up the nut.  Per advice I got in a different place, I'll also freeze the bearing with the thought that it might shrink just a wee bit while helping protect it from the hot nut(?).

blythkd - Roger that. I double- and triple-checked the rotation direction because, as you pointed out, I get one shot to make it work. It would be just like me to get the bearing pushed in - sticking my chest out all proud of the accomplishment - just to find out I put it in backward.

Thanks again!  I'll let you know how it goes.

-Adam

[adam]

Well, it's not perfect, but it's good enough.

I don't have a toaster oven, but I do have a heat gun - so, I used that to heat up the nut. The bearing went in the deep freeze for a few hours (I think it's about -10°F). Also, I ended up putting a dab of 3-in-1 on the outside of the bearing, but it didn't seem to make any difference. Long-story-short: the bearing isn't where it's supposed to be (nearly flush with the nut), but is sticking out about 1/8". I only stopped pushing when the handle on my vise started bending(!) under the pressure of the 30" cheater bar. What a pain! I'm just glad the bearing survived under that much force.

However, it's in far enough to get the pull cord cover installed the way it's supposed to be and, most importantly, the saw starts and runs!

So, I'm going to return my neighbor's property and do a little preowned chainsaw shopping.

Thanks, again, for your help and guidance!
-Adam

[blythkd]

Glad you got it done. Seems like they usually stick out a little bit. As long as there was room so it doesn't rub the starter pulley, you're good. Sounds like it works. Good deal.