Bearings

[Fast6hand]

I know that I have been posting a lot of questions lately, but I'm right in the middle of tearing my motor down. I wanted some insight on how to determine if a bearing needs to replaced. It's probably pretty simlple logic but I just want your guys input. And, can you reuse bearings? I have another set of crankcases and was wondering if I could remove them safely if they could be reused. Thanks so far for all the info given to me. I will be updating periodically about the build.

 

[Awk08]

IMO.....once your that far into it, replace all the bearings with new, that way you know what you have...new.
and there's no risk of a bad bearing being reused, and possibly taking out everything you've just done

 

[harley1-5]

I agree with awk and bearrings are relatively cheap

 

[Fast6hand]

IMO.....once your that far into it, replace all the bearings with new, that way you know what you have...new.
and there's no risk of a bad bearing being reused, and possibly taking out everything you've just done

When you put it like that I couldn't agree more. By the way, is there a good DIY/video on how to remove main crank shaft bearings?

 

[harley1-5]

ken occonor has great engine assembly vids on utube

 

[Fast6hand]

ken occonor has great engine assembly vids on utube

Yea I've seen them all. But I haven't actually seen one for removing the bearings. Does anyone have the link?

 

[harley1-5]

not sure on the link but I have watched the vids he heats a metal shaft and uses it to transfer heat to the bearrings and they drop right out

 

[Herpderplol]

Weird they didnt come out on the crankshaft... I would say, use a drill press (not on) and press them out. Unless you have a press, use that

not sure on the link but I have watched the vids he heats a metal shaft and uses it to transfer heat to the bearrings and they drop right out

Thats for putting them on, the center piece expands in the heat, making it slip right onto the crank.

 

[Fast6hand]

I'm gonna try the same method of heating the crankcase up slight around the bearing and hopefully if it will fall out. Thanks for the input guys!

 

[240Fun]

take the alignment pins out of the case halfs so the mating surface is flat. Clear an area big enough to beable to lay the case half on with the mating surface down on the table, i used my work bench with a piece of plywood on top your gonna need some welding gloves so you can handle the case it may be warm. Heat the area right around the crank bearings with a mapp gas torch until you just start to see some of the oil burning off it will start to smoke then take the case and slam it on the bench mating side down keep it nice and square to the bench and the bearing should fall out of the case if not you can heat the case and cool the bearing with ice but you gotta be fairly quick or if you have access to a press it a nicer way of doing it

 

[Fast6hand]

take the alignment pins out of the case halfs so the mating surface is flat. Clear an area big enough to beable to lay the case half on with the mating surface down on the table, i used my work bench with a piece of plywood on top your gonna need some welding gloves so you can handle the case it may be warm. Heat the area right around the crank bearings with a mapp gas torch until you just start to see some of the oil burning off it will start to smoke then take the case and slam it on the bench mating side down keep it nice and square to the bench and the bearing should fall out of the case if not you can heat the case and cool the bearing with ice but you gotta be fairly quick or if you have access to a press it a nicer way of doing it

Ok. Seems pretty easy. Slamming it down seems rough. Maybe a towel on the bench would be more appropriate, not to score or damage anything. But thanks for the tip.

 

[Fast6hand]

So I got them out easily. I heated up the area around the bearing with a heat gun to about 200 degrees, turned the case over and tapped the bearings out with a large socket with an extension. They popped right out. The last 3 bearings I need a blind bearing puller. I had a extra case with bearings that I practiced on. And of course the bearings are not being reused. It was simpler than I thought it was going to be. Thanks for all the suggestions.

 

[Fast6hand]

Just ordered all 9 bearings for the motor! I can't believe I'm this excited. Just not sure how to get the pilot type bearings in the case. Any suggestions?

 

[240Fun]

I didn't realize you were gonna get new bearings that's why I didn't mention using a socket and hammer on them slamming the case does seem kinda harsh I do it all the time taking model airplane motors apart to clean and rebuild them and never had an issue

 

[Fast6hand]

I didn't realize you were gonna get new bearings that's why I didn't mention using a socket and hammer on them slamming the case does seem kinda harsh I do it all the time taking model airplane motors apart to clean and rebuild them and never had an issue

No problem! If I was trying to reuse them I would of probably tried that. Thanks for the info though. Much appreciated.