Steering Stem Bearing Install

[doctorgonzo]

I trashed my lower steering stem bearing last night trying to install. I was using the method if 1.25 ID pipe. I had bought 1.0 ID galvanized originally, which was too small of course, so I went back and not wanting to pay $12.00 for another hunk of galvanized got PVC (I had seen others talk about doing it with PVC). Well, in the process of beating the new bearing on it broke apart, trashed. This was followed by the fun of getting the inner ring of the now trashed bearing back OFF the steering stem. Not a fun or productive night. I ordered another bearing that will be here the first of next week, but before I try again, any hints. I greased the stem before I started, but I was having to beat the bejesus out of that thing to get it to move at all (eventually breaking it).

Tips and tricks appreciated.

EDIT:
Step one is going back and getting 1.25 ID METAL pipe.

[Billy Ricks]

Maybe try freezing both parts or have a machine shop press it on for you. BTW, you should be able to pick up those bearings at any bearing shop.

[reddirtrider]

Put it in the freezer before installing.

[doctorgonzo]

Put it in the freezer before installing.

After it was too late I thought "Crap, I should have frozen them".

[spyug]

Reddirt is right. The freezer is your friend. They should just more or less slip in.

Another method, rather than pounding on them is to use a suitably long length of threaded rod with a large washer and nut on either end. tighten to draw the bearings in. A smear of grease on the outer surface of the bearing race also helps.

Now when putting the lower triple tree on also give it the freezer treatment and it should slide right in.

More finesse, less brute force

Let us know how it goes next time.

cheers,
Spyug

[doctorgonzo]

Thanks guys, I will do the freezer treatment. I have made multi-hundred dollar mistakes on this bike (as I learn motorcycle mechanicing), a $15.00 trashed bearing is a fairly cheap lesson learned.

[atchbo]

With respect to the 'you can get em anywhere' comment, are you talking about the older tapered bearings or the newer sealed bearing?

Or put another way, does anyone know a generic description for the neck bearings in the 1977 GS400B?

Atchbo

[doctorgonzo]

With respect to the 'you can get em anywhere' comment, are you talking about the older tapered bearings or the newer sealed bearing?

Or put another way, does anyone know a generic description for the neck bearings in the 1977 GS400B?

Atchbo

Mine is a 1981 and it has non-sealed tapered bearings in the steering stem. The new All Balls wheel bearings were sealed, but my OEM ones I took out were open and greased on the back side.

[Agemax]

if you are trying to fit a new bearing to the head stem YOU DO NOT FREEZE BOTH PARTS! you want to freeze the head stem and heat up the bearing. freezing will contract the stem, heating will expand the bearing.
then it will drop straight on.
avoid direct heat, ie a blow torch. use an induction heater or pop it in the oven for a while

[doctorgonzo]

if you are trying to fit a new bearing to the head stem YOU DO NOT FREEZE BOTH PARTS! you want to freeze the head stem and heat up the bearing. freezing will contract the stem, heating will expand the bearing.
then it will drop straight on.
avoid direct heat, ie a blow torch. use an induction heater or pop it in the oven for a while

Got it. Fingers crossed for it "dropping on".

[Billy Ricks]

If heating expands the bearing won't that defeat the purpose of freezing the bearing? I figured freezing both parts would would give a bit of extra clearance. I could be wrong.

[Agemax]

If heating expands the bearing won't that defeat the purpose of freezing the bearing? I figured freezing both parts would would give a bit of extra clearance. I could be wrong.

if you are fitting a bearing on a shaft then you need to expand the bearing or shrink the shaft, heating expands, freezing contracts.

[Hammered]

I just put mine on today. A couple hours of the Stem in the freezer is all you really need. Just remember to pack the bearing and run a piece of Emory cloth around the part of the shaft that the bearing sits. A little grease on the bearing seat and a piece of 1 1/2" PVC, tap the bearing down, BUT DONT FORGET THE SPACER AT THE BOTTOM> Sorry bout the caps but I got 2 taps into it and looked over to see, thats right the bottom spacer. I played hell getting the bearing back off. Im not sure how much trouble it would be to not use the bottom spacer, but if you have it, use it I guess.

[twiggy2cents]

quick mcgyver tip, i learned this in school.

When heating a bearing to make it expand (and when we say expand it will make the inner hole of the bearing increase) set the bearing on an incandescent light like a 75 watt or 100watt light bulb(normal one) let it set there for about 15 minutes and with gloves very quickly slide it on what you want.

I have done this in manual transmissions multiple times in place of a hot plate. Trust me the light gets hot enough just give it some minutes to transfer all of its heat

[Billy Ricks]

quick mcgyver tip, i learned this in school.

When heating a bearing to make it expand (and when we say expand it will make the inner hole of the bearing increase) set the bearing on an incandescent light like a 75 watt or 100watt light bulb(normal one) let it set there for about 15 minutes and with gloves very quickly slide it on what you want.

I have done this in manual transmissions multiple times in place of a hot plate. Trust me the light gets hot enough just give it some minutes to transfer all of its heat

After I gave it a little more thought I figured the expansion would be outward increasing the size of the bearing center.