Remove left side main bearing

I seem to not be able to remove the left side crank bearing... The inner part with the rollers was destroyed before I took the engine apart so whats left is the ring.

I've tried heating it up and according to some posts on the forum it should have just popped out, but it didnt even if i tried to hit it (as well as you can from the inside...)

Any special method or tool I should use?

I've got a machine workshop so I could make my own tools

I dont want to do something that can hurt the case, as example welding something to the bearing

Question 2, is there any risks with putting a freezed bearing into a heated case? Like cracks?

I seem to not be able to remove the left side crank bearing... The inner part with the rollers was destroyed before I took the engine apart so whats left is the ring.

I've tried heating it up and according to some posts on the forum it should have just popped out, but it didnt even if i tried to hit it (as well as you can from the inside...)

Any special method or tool I should use?

I've got a machine workshop so I could make my own tools

I dont want to do something that can hurt the case, as example welding something to the bearing

Take an arc welder and run a bead in the inside of the race, no more than halfway around is needed. When it cools, the bearing will slip out with your fingers.

watch all three videos in the series

http://www.rockymountainatvmc.com/videos.do?videoId=99

Didnt answer any of my questions

Take an arc welder and run a bead in the inside of the race, no more than halfway around is needed. When it cools, the bearing will slip out with your fingers.

I'll try that, just have to find something to protect the case from me :thumbsup:

Didnt answer any of my questions

I'll try that, just have to find something to protect the case from me :thumbsup:

With a MIG, its much easier than a "(((buzz box)))

Ground the case, set the tip right next to where you want to start, then pull the trigger (MIG) , lay a nice bead int he center. Doesnt havre to look pretty. As the weld cools, the bearign race will contract and shrink. An old tyimer showed me this many years ago. Has NEVER failed me yet.

If you are going to do this with a buzz box, strike an arc on a scrap metal piece and get the electrode nice and warm first, then weld the bearing.

I've got a MIG welder, I'll try it out tomorrow, thank you! =)

I've got a MIG welder, I'll try it out tomorrow, thank you! =)

I expect a full report on this outcome and some + feedback. :lol:. :thumbsup:

Question 2, is there any risks with putting a freezed bearing into a heated case? Like cracks?

Should be completely risk free if you use a normal fridge (~ -18 degrees C), and heat the aluminum case to 150 degree C or less.

Now if you you use liquid nitrogen...

Should be completely risk free if you use a normal fridge (~ -18 degrees C), and heat the aluminum case to 150 degree C or less.

Now if you you use liquid nitrogen...

Thanks mate :thumbsup:

If the race still doesn't come out, I took the very same problem to the local machine shop. He jig'd it up in the overhead milling machine, 15 minutes and $30 later, We were installing the new bearings. WELL WORTH IT!

But next time, I'll try the welding trick 1st.

I was able to remove it by welding. It was still pretty stuck tho, had to hit it pretty hard to make it move...

Now I'm only waiting for a new rod, which is due 2/7... Four weeks total mid summer without the bike feels veeeery nice...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now