Replacing tapered roller steering stem bearings - need advice

Started by d0n, July 21, 2006, 05:02:20 PM

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d0n

PLease excuse the dumb questions... ???

Ok, I took it all apart today. Surprisingly, it only took about 2 hours. It was pretty straight forward so I think putting it back together will take even less time. I won't have to spend the extra time breaking bolts loose.

The bottom race was really pitted. You can see and feel where each individual bearing sat. The bike must have sat unused for many years to make those indentations.

In this pic there's a silver race on the bottom of the stem and below that is a rubber seal of some sort. Do both of these need to be removed? How do I get them off?



In this pic you see the new bearings and dust seals (I think they're dust seals). The bearings sit in a tapered steel ring. I know I need to pack the bearings with grease and then install them. Since there were no directions and the yamaha manual says nothing about this procedure... I don't know how to install em or really where each piece goes or what side needs to be up or down.

Also, in the steering stem there's another race that held the ball bearings for the top. Does that need to come out too?


d0n

I just looked at motorplows blog again and I think I understand now.

The old races are removed, the new races are tapped in until they're flush with the surface, then the bottom bearing goes on the stem, slide it up into the hole from the bottom, put the top bearing on, the dustcap and then tighten it down?

Sounds about right?

MotorPlow

That sounds about right.
All four Races need to be removed. I left the rubber seal under the lower race.

Night Vision

dOn, when you disassembled.. did you leave the bucket intact and just pull everything forward or down out of the way?

I completely gutted the bucket. and that is probably the hard way... but I had to re-clean my connections anyway...

Those seals are grease seals, not dust seals really... that pitted bottom race on the triple clamp gets pried/bashed off... when you are done, you should have four old races and the ball bearings.

Harbor Freight has a two piece brass drift set for about $11

if the oem seal is in good condition, you can use it to take up the gap between the new bottom seal and bearing cage and the "lip" or "stop" for the old race.

It helps to put the two new races and the steering stem in the freezer for a night or two.

the new upper race goes in easy with a block of wood and hammer. I had a brass disc from work that worked nice. The top race doesn't go flush into the stem, sticks up a bit.

the lower race can be driven up into the frame with a piece of 1" pvc pipe and the right size fitting.... the lower cage can be driven onto the steering stem,  again with a piece of 1" pvc pipe and a fitting. See MP's blog for a pic of the PVC tool or use the buddy peg method..........

if you go pvc... take the lower race and cage to home depot and find the right size "adapters" that will fit the race and cage... (should've kept receipt, oh yeah... wanna buy 7 feet of 1" pvc? can't get just 12" ya know)

-edit- the "adapter" that I used on the 1" pvc to pound in the lower race was simply a 1" to 1" butt end connector, the diameter of the connector (1 5/8" od) just fits inside the lower race nicely....

the other "adapter" is a 1 1/2 x1 thingy (see MP's blog, or buddy peg)



as far as order of parts...

on the lower it goes .... triple clamp with steering stem... new bottom seal (lip up, flat side toward triple clamp)....pound the grease packed lower roller cage (taper up) onto the froze steering stem. I think I had the seal on the cage and  pounded them simultaneously.

bottom race (froze) gets pounded up into frame so the taper faces down and matches up with bottom cage taper up...

on the top side... you pound upper race into frame with taper up... place upper roller cage into upper race with taper down... place seal (lip side down, flat side up onto roller cage

inset triple clamp/stem into frame neck, through roller cage and seal.... put on original dust cap... the two castle nuts.... that's it ::)

ps... I don't write service manuals and usually end up doing things the hard way (at least once)  ;)

do a couple of dry runs... it'll make sense










if it ain't worth doing it the hard way....
it ain't worth doing it at all - Man Law
;D


if it ain't broke..... take it apart and find out why


don't give up.... don't ever give up - Jimmy Valvano

d0n

thanks for that. I'll print it out and read it while I'm looking at all the parts. The bike is at my friends agarge a few miles away.

I took everything off the front... even removed the entire front braking system. I didn't open it up but I did take it all off.

I took the headlight and the frame its attached to off also. And, the gauges, the turn signals, the horn, the big rubber boot and mount that protects all the wire connectors etc etc etc... pretty much everything on the front end I removed.

It looks kind of scary at this point!  :o As the bike's getting more and more naked... I'm thinking, "how in the hell am I ever gonna get this all back together!?"   ;D

I didn't take any pics or mark any wires. The wire connectors all seemed like they'd be pretty easy to reconnect. The wires are color coded and the plastic connectors mostly will only fit back where they came from. Ya know?

I'll take some pics tomorrow and post em.

Night Vision


dOn, see my edit about the pvc tool

Quote from: d0n on July 21, 2006, 10:52:06 PM
It looks kind of scary at this point!  

hahaha... my neighbor saw my bike and thought I Rothlisburgered  :o someone
if it ain't worth doing it the hard way....
it ain't worth doing it at all - Man Law
;D


if it ain't broke..... take it apart and find out why


don't give up.... don't ever give up - Jimmy Valvano

d0n

NV, after doing the job tonight your instructions made perfect sense. You SHOULD write manuals!  thanks bud!   :)

Tdub

Just heat the inner race of the new bearing with a heat gun or hot heat-sink and it will fall right into place...no drift or driver or freezer required. Tdub
Always Looking for the Next Race

h2olawyer

Mine wasn't quite that easy.  I froze the stem & heated the bearing with a heat gun.  I still needed to use a small brass drift & light tapping to get the lower bearing to fully seat.  Not much tapping but it didn't quite fall fully into place.  That method does make things much easier, though.

When working with such close tolerances, you may end up with a bearing at the small end of the tolerance & a steering stem at the large end.  This can cause minor fitting issues.  It doesn't happen often, but when it does, it can drive you crazy trying to get parts to fit right.

Glad I took a class in quality control when I was trying to figure out what to get my degree in.   :D

H2O
If you have an accident on a motorcycle, it's always your fault. Tough call, but it has to be that way. You're in the right, and dead -on a bike. The principle is not to have any accident. If you're involved in an an accident, it's because you did not anticipate. Then, by default, you failed.

Brian Moffet

Quote from: h2olawyer on July 23, 2006, 01:27:57 AM
Glad I took a class in quality control when I was trying to figure out what to get my degree in.   :D

took a class in quality control and ended up being a lawyer? Hmm...  ;D

Heating the bearing will have a much larger affect on putting the system together than freezing the shaft.  There's just too much mass there to effectivly shrink.  But if you've got a big enough freezer, go for it  :)

Night Vision

the reason I didn't heat the bearing cage is I didn't want to melt the grease on a fully packed bearing. You can pack the bearings after they are installed, but I like the palm packing method.

I have noticed an anomaly with the roller bearings though.... the steering is so sensitive and precise that when I have the shark on..... it will wallow a bit in turbulence. both traffic turbulence and slight cross winds  >:(
might just have to get nakey  ;D
if it ain't worth doing it the hard way....
it ain't worth doing it at all - Man Law
;D


if it ain't broke..... take it apart and find out why


don't give up.... don't ever give up - Jimmy Valvano

Tdub

One side effect of too tight steering head bearings is a "wallowing" feel. Tdub
Always Looking for the Next Race

Night Vision

Quote from: Tdub on July 23, 2006, 02:07:15 PM
One side effect of too tight steering head bearings is a "wallowing" feel. Tdub


hmmmm. I'll try backing them off. I've heard some much about them not being tight enough.....thanks

I'm sorry you left the team, but it's nice having you around more Tdub   :D
if it ain't worth doing it the hard way....
it ain't worth doing it at all - Man Law
;D


if it ain't broke..... take it apart and find out why


don't give up.... don't ever give up - Jimmy Valvano