Pressing on Lower Steering Stem Bearing

[strawbobrob]

I am replacing the steering stem bearings.  Other threads were very helpful and I've gotten the races out and the lower bearing of the steering stem off.  Before starting to build back I read a thread that indicated the best way to get the new lower bearing on was to heat it up in new motor oil, and that way it would just pop on there without force, which was better for the bearing. 

I heated up the bearing in a small pot of new motor oil on the stove for 7 minutes.  The oil started to smoke so I took it off the stove, brought it out into the garage and despite heating it about as hot as I dared, it still required pressing to get on (threaded rod, nuts and washers, old race turned upside-down..).  It's on now and seated.  But the bearing is now black from the heating.  I thought it was the oil on it but it's not.  Maybe not "black", maybe just a charcoal gray, pretty dark. 

So, I've packed the bearing and it seems fine, rolls around nicely, but the question in my head is, did I damage the bearing heating it up in oil, which was hot enough to seriously smoke the oil?  What are the chances it is now be brittle and will fail, etc.? 

Also for others trying this for the first time, a little advice--getting out the lower race of the steering head is not hard at all if you make the right tool--that perfectly bent screwdriver shown in other threads-- about 10 pops with that and a hammer and it was out.  Making the tool was a good half hour to get it exactly right.  BUT , damaging the inner wall behind the race is very easy.  the tool scratches down the inner face as the race comes out, unless you are aware and very careful.  The burrs created then need to be filed/sanded before the new race will go in= no fun.

So, what is your judgment?  Did the heat damage the bearing, and do I need to take it off and replace it?  Thanks.

[fordmano]

No idea if you caused any damage, I would think not think so but I have been wrong before about a lot of different topics.

Another idea to ease the install would be place the steering stem lower section in the freezer while your heating the bearing,,,, bearing is expanded and the stem would be slightly contracted.... (Maybe)

[Warlock]

I am replacing the steering stem bearings.  Other threads were very helpful and I've gotten the races out and the lower bearing of the steering stem off.  Before starting to build back I read a thread that indicated the best way to get the new lower bearing on was to heat it up in new motor oil, and that way it would just pop on there without force, which was better for the bearing. 

I heated up the bearing in a small pot of new motor oil on the stove for 7 minutes.  The oil started to smoke so I took it off the stove, brought it out into the garage and despite heating it about as hot as I dared, it still required pressing to get on (threaded rod, nuts and washers, old race turned upside-down..).  It's on now and seated.  But the bearing is now black from the heating.  I thought it was the oil on it but it's not.  Maybe not "black", maybe just a charcoal gray, pretty dark. 

So, I've packed the bearing and it seems fine, rolls around nicely, but the question in my head is, did I damage the bearing heating it up in oil, which was hot enough to seriously smoke the oil?  What are the chances it is now be brittle and will fail, etc.? 

Also for others trying this for the first time, a little advice--getting out the lower race of the steering head is not hard at all if you make the right tool--that perfectly bent screwdriver shown in other threads-- about 10 pops with that and a hammer and it was out.  Making the tool was a good half hour to get it exactly right.  BUT , damaging the inner wall behind the race is very easy.  the tool scratches down the inner face as the race comes out, unless you are aware and very careful.  The burrs created then need to be filed/sanded before the new race will go in= no fun.

So, what is your judgment?  Did the heat damage the bearing, and do I need to take it off and replace it?  Thanks.

Use your old inner race. Cut it and use a piece of pipe with it and all thread rod and use the all thread to pull it in place. Can't remember right now, but I have a set up at the house for this, but on the ship at present.
David

[Daniel Meyer]

Heating it in oil there's not a chance you heated it enough to damage it.

[longrider]

for those who install the bearing a bit of info on heating.  the oil should be heated to approx 300-350 f.  the bearing should be hung by a piece of wire or rod so that it is off the bottom.  to expand the molecules fully takes about 30 minutes.  No kidding!.  if the bearing lays on the bottom it will tend to get hot enough to burn the oil on it, on your install,   personally I think no damage has been done.  I do this twice yearly on crankshafts as large as 4in diameter. 

warren

[Madmike]

clean off the carbon and you should be good.  If you want to get set up for doing this again keep your eyes open at garage sales etc. and pick up an old electric household deep fryer, you can put your oil in this and heat it up and leave the bearing in it long enough to get full heat.  If you want to shrink stuff you can use the house freezer or get or make some dry ice - or where I live we can just leave it outside most winter days and get it fairly cold to shrink it.

[strawbobrob]

Ok, thanks to you all--it sounds like you all came out on the side of the bearing being fine and I learned alot about how to heat that up.  Makes a lot of sense and explains why I failed.  Today everyone is complaining about how the kitchen smells.  A cup of burnt 30 weight, anyone?

[strawbobrob]

Just to close out the topic I have gone 700 miles on the 'cooked' bearing and the steering is perfect.  All I need is another 150,000 and I'll be satisfied.

[Cattman]

Maybe I'm looking at this backwards, but don't you freeze the bearing to contract it for easier install?   ??? That's what I/ve done and seen dealers do for wheel bearings.

[Valker]

Maybe I'm looking at this backwards, but don't you freeze the bearing to contract it for easier install?   ??? That's what I/ve done and seen dealers do for wheel bearings.

It goes on OVER the stem. I just did mine, and I think I'll have a machine shop press it on next time... I tried freezing the stem overnight and heating the bearing. I still had to drive it on HARD.