OzVMX Forum

Clubroom => Tech Talk => Topic started by: CRTAD313 on September 26, 2012, 06:39:20 pm

Title: Bearing removal
Post by: CRTAD313 on September 26, 2012, 06:39:20 pm
I'm replacing a set of steering head bearings this weekend and was told the easy way to remove the bottom one is run a bead of weld round the cone with an arc welder.
Question is will a mig welder work  and any other tips?
Title: Re: Bearing removal
Post by: tony27 on September 26, 2012, 06:50:10 pm
Should work, normally only need to do a couple of small beads. As the weld cools it causes the steel to contract & quite often the race will fall out under it's own weight
Title: Re: Bearing removal
Post by: Slakewell on September 26, 2012, 07:12:26 pm
Mig/stick/tig even OXY will work
Title: Re: Bearing removal
Post by: frostype400 on September 26, 2012, 07:15:40 pm
I am doing this too at the moment what is the best way to get the new bearing back on?
Title: Re: Bearing removal
Post by: Slakewell on September 26, 2012, 07:21:55 pm
Having been to bearing school (Truely) 
I use a large bit of key steel Normal 20x20 and about Penis length 200mm in my case  ;D
A good 1kg ball hammer.
Place it in the freezer over night will not hurt. 
Ok a bit extra if you have trouble getting it in stright at the start. Steel shop/  buy two bits 50x25 flat bar 150mm long and 1 bit 1/2 inch threaded rod with 4 nuts and a few washers. drill two 5/8 holes in both bits, cut threaded rod to correct size place on the head stem bearing on the F/B and slowly tighten the nuts it should go easy if it dosent your alignment is wrong. Clear as mud  ;)
You can also use your steering stem with just the outer shell on the bottom if are very carefull 
Title: Re: Bearing removal
Post by: evo550 on September 26, 2012, 07:44:24 pm
I'm replacing a set of steering head bearings this weekend and was told the easy way to remove the bottom one is run a bead of weld round the cone with an arc welder.
Question is will a mig welder work  and any other tips?
Getting the cone out of the frame is the easy bit, I just feed a long handled flat screwdriver down through the steering and give it a tap with a hammer, always just drop out. The hard bit is getting the bearing off the bottom of the steering stem.
Title: Re: Bearing removal
Post by: dt tas on September 26, 2012, 08:52:00 pm
When i put the new cone in i get the old one and run it around on the bench grinder to make it a tade smaller then use that on top of the new one that way it is the right size .Now have a small collection of cones so mostly have the right size .Also use a solid screw driver to punch them out .cheers george
Title: Re: Bearing removal
Post by: topari on September 26, 2012, 10:23:23 pm
My special tool. Welded to the bearing race and then bang. Works everytime.

(http://i663.photobucket.com/albums/uu354/topari/IMAG0122Medium.jpg)
Title: Re: Bearing removal
Post by: Frank M on September 26, 2012, 10:32:36 pm
for easy removal next time, grind two small oposite grooves in the bearing shoulder in the frame, befor you install the outer bearing ring.
So you can punch out the bearing from the upper side with a long small driver etc.
Title: Re: Bearing removal
Post by: CRTAD313 on September 27, 2012, 06:40:52 pm
ok thanks