Lower Stem Bearing Removal Vintage

[HuskyT]

Putting in new stem bearings and races

What is the best way to remove the lower steering stem bearing?

83 CR500 triple and stem.

I can't get this thing to budge. Was going to keep it as a spare but I have now destroyed the seal. Is their a puller that is reccomended? Best suited...? if so would be great if someone could explain or post up a pic. I'm confident one of you guys will tell me the right way to do this.

T

 

[1983XC175]

Tim, I would use a press. you press the steering stem out thru the bottom of the lower clamp.Then, press the stem back in. A local machine shop can easily handle it.
Bill

 

[Moody390]

Alternative to ^^^ which is the conventional way haha. For Pinion Gears in Car diffs (similar bearing arrangement) I;
1) Smash the race off, and drop the rollers.
2) Then dry ice the whole lot to chill it.
3) Light the oxy/acet, and heat 1 and only 1 spot.
4) A Couple of light taps on the lower ridge (looking at it inverted) should be enough to slide it off the journal.

If uo press it off, be sure to wind a nut on the thread before pressing. Also, there is a circlip underneath, which i didn't see haha.

 

[Husq.fleet]

I put the stem in the vice and used a air hammer because I wasn't reusing it.

 

[schimmelaw]

I second Husq.fleet. Ez pz Japonez.

 

[fran...k.]

The easiest thing if you have a 4 1/2 inch angle grinder is to grind almost all the way through the inner race. After demolishing the rollers and grinding which can be done away from parts needed to be clean I heat the thin portion with a small oxy acetylene flame but I am not sure if that is necessary all the time. If necessary you could grind in two spots. Upon attempting to spin the race with a hammer and punch it breaks at the thin spot and comes off easy. I do believe this is easier than the other suggestions you have got so far.

Fran

 

[Motosportz]

If you have a wire feed welder you can knock the bearings off so you have just the race. Put a bead of weld on the race, this will heat it and expand it and it falls off.

 

[HuskyT]

I put the stem in the vice and used a air hammer because I wasn't reusing it.

Just to be sure here.... all I want to do is remove the lower stem bearing off of the stem. I'm asuming there is no is no need for me to press the stem out of the lower triple?

So do I just clamp the stem upside down in a vise ( with lower triple still attached) and use a hammer and drift or air hammer ( do not have one) on the bearing itself ( not saving it) and pound it off by working around 360 degrees?

Will the new bearing slip on or will it require pressing it on to seat it? can I use a brass drift or similar to seat it? I'm assuming you want to avoid tapping on the new bearing as much as possible.


T

 

[HuskyT]

I starting to see a pattern here of heating with an oxy/acet torch as maybe the easiest way. And - or weld to get the bearing warm and expanded.

Short of that... grind with a angle grinder( i have one) and pound/rotate until it spins or breaks off.

What about going back on with the new bearing? Best way to re-install?

T

 

[fran...k.]

I have changed quite a few of these things and don't recall having any problems putting the new bearing on. On some applications, mix and match sutff you need a shim under the bearing and then you are stuck if it is on with the wrong shim or you perhaps forgot the seal. I would find a piece of pvc pipe which fits over the stem and rests on the bearing without damaging it and have a piece of 2x4 say a foot long to smack the pvc pipe with. heat the bearing but not too much to damage the seal. In the event that it doesn't go on all the way use the pvc and 2x4. Chances are a it will go right all the way down but the threads on the stem itself will pull it in. Chances are you will be less sure that the races in the frame are seated and tighten that up more with the neck races in mind. I grind an old frame race so it goes in quite easily and drive off that if necessary. You are changing those races too aren't you?

Fran

 

[fran...k.]

Do what you want but I say do not weld on it that is for when the thing you want to remove is on the inside. Things get smaller when the welding is over. My talk of the flame is just to weaken the metal and perhaps break the spell. If you get it as thin as you dare it will get red real quick before much else gets hot. it might even break because as steel is heated it expands and in it's hot state it upsets or compresses in on itself. as it cools it contracts and might just crack nice and easy due to the tension it will now be under.

 

[Motosportz]

Do what you want but I say do not weld on it that is for when the thing you want to remove is on the inside.

Done it several times. Heat expandes things. Weld bead on the race makes the race bigger and it falls right off.

To install put the lower triple / stem int he freezer for a few hours and get the bearing warm, should go right on with a few light taps.

If you have a press pressing the step out is the EZ way, strips the bearing off as it comes out then you just press the stem back in. Simple.

 

[pcnsd]

I 've use two methods depending on the tools available at the time. Both require removal of the bearing cage and rollers.

1. Weld a 1 " bead on the inner race and knock off by tapping the stem on a study but non-marring surface (2x4 on concrete works)

2. Use a Dremel cutoff tool to cut a diagonal slot across the bearing face as deep as you can without touching anything else. (stem or clamps) Then use a cold chisel to crack the bearing race and knock off as above.

Regards,
PC

 

[Moody390]

Just a tip, Do Not use a brass dolly or a copper hammer to install the new bearing. other wise you'll spend hours and loads of fresh oil trying to clean it out.

 

[HuskyT]

Here is what I went with!

Several people suggested this to me. It worked amazingly well. Had lower bearing race off in under five minutes. Heat on the race is the key. Grinding creates heat and allows bearing race to slip off stem.

Air Die grinder or angle grinder
Mount stem in a vise. ( I wrapped mine in a bath towel to avoid marking up the shaft)
Grind. Examine with light to make sure not cutting into stem. Grind some more. Turn grinder and cut thick portion of bearing race ( removes a lot of material.
When almost through hit it with a chisel and mallet in the groove that you just created. Bearing spun instantly and fell off. Rubber seal is kind of messy with the die grinder . Very quick and easy. Just be carefull not to mark the stem with the die grinder.

Pics:

Overall view:

Close up of grind on lower inner bearing race and seal:

T