LC4 Steering head bearing, a how-to-guide...

Discussion in 'Thumpers' started by laramie LC4, Sep 15, 2006.

  1. bikemoto

    bikemoto Tyre critic

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    Thanks for that, will have to get it done now.
    #81
  2. todd83-900t

    todd83-900t Been here awhile

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    Two years & 6k offroad miles ago I replaced the bottom headset bearing/race and both rubber seals. I used BelRay waterproof grease and filled in the ignition lock slot on the stem with RTV to keep the water out. Today I dug back into the headset and found that the bottom bearing was full of mud like grease and it will need to be replaced.

    Question: Has anyone found a better way to keep the water and dust out of the headset bearings or did I discover why you should clean then every year? I envision using some neoprene or inner tube to form an additional barrier, but that isn't very satisfying. Isn't there a loctite product called KCO (keep the crap out) that could be applied here and on the prolink bearing?
    #82
  3. GodSilla

    GodSilla I did that.

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    I have seen a trick used by enduro riders here where they tap into the headstock and thread the hole to take a grease nipple, then after each ride simply apply a grease gun and pump a couple of shots gently intio the headstock, the new grease should displace any dirty grease out the ends. Wipe clean with a rag and you're done.:D

    It's basically what I do with the rear suspension linkage on my XR after each ride, and the original bearings are still good after 13 years.
    #83
  4. bmwktmbill

    bmwktmbill Traveler

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    BMW riders have done this to their airheads for years, never heard of a failure.
    b
    #84
  5. todd83-900t

    todd83-900t Been here awhile

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    Thanks GodsSilla and bmwktmbill for the grease nipple idea. I suspect it would work but in the process also make a mess. The grease would probably ooze out of the upper/lower bearings and the stearing lock on the side of the headstem. This would put me at odds with my clean freakitist flare-ups. Yes, I know, I want it all, a clean bearing and a clean bike.

    Are there other LC4 riders that have managed to keep their bottom headset bearings clean. Anyone? If so what's the trick?
    #85
  6. 30Bones

    30Bones Long timer

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    Glad I saw this on top tonight for some info I needed. I had mine rebuilt and added the are release valves and they break off easy. :lol3 I have another on the way. The left for is going back in real tough though. Right side slide right into place, left is about half way in the upper mount and it's bound up pretty good. Any helpful tips would be appreciated.
    #86
  7. bmwktmbill

    bmwktmbill Traveler

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    Bones,
    Spread the clamps with some small screwdrivers, be gentle, slide the leg up and remove, do the other side....
    b
    #87
  8. 30Bones

    30Bones Long timer

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    I tried that, but need another set of hands I think as it was not working and I was not prying too hard. Thanks
    #88
  9. meat popsicle

    meat popsicle Ignostic

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    my fork service how-to has a bit on this: find some little widget to hold the bottom one open while you pry the top with one hand and slide the leg up with the other. come on man, haven't you ever tried to pry her open with you know what, while one hand is holding the rear and the other is trying to open buttons on the sweater? :evil
    #89
  10. 30Bones

    30Bones Long timer

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    Well you put it in terms I can relate too and now I got it! They will be in tonight after I get home from the bar. :freaky
    #90
  11. bikemoto

    bikemoto Tyre critic

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    I've never had to resort to spreading the clamps on WP48s yet; in fact I can't remember the last time I did that on any set of forks. From my notes-to-self-department:

    First tip: twist the fork tube as you slide it up. One direction will be almost impossible, the other easy. I put this down to the triple clamp edges (at the spit) biting in one direction and not the other.

    Second tip: you need a good grip to do this. If your hands are even slightly oily - wiping them on a rag is not sufficient - you may not have enough grip. Hold the forks with a clean rag to improve friction.

    Third tip: (aka stating the bleeding obvious) the upper and lower clamps have to be perfectly in line. Sometimes a really good shake to loosen any binding and let everything settle naturally lined up helps. Most notable on the second fork leg, as inserting the first can leverage the clamps out of line, and you are left thinking, "but I got the first one in, so they must be lined up :scratch" This technique is also useful to get the forks out, to break them loose.

    Remember: a firm fit with a bit of friction is best!! :lol3
    #91
  12. KTManiac

    KTManiac Adventurer

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    Hi everyone.

    I've had issues of this kind myself lately :

    first, while working on the forks of my '90 (!) 600 lc4, I notice some "notches" in the movement from side to side of the steering... I ordered a pair of bearings from the KTM dealer. And the gaskets as well. Took all apart, found out that indeed the almost 20 years old bearings were totally shot :eek1.
    Biggest issue was to remove the lower bearing. No way it would move while following the procedure described earlier (remove the outer ring and hit the race with a hammer and screwdriver). I tried cutting the race with a grinder, and it seems the heat produced made it at last get out of there (of course, I managed to slightly damage the stem :cry)
    Then I mounted the new bearings flawlessly (27 EUR a piece from KTM), noticing the reference number was indeed not 331274, although it was SKF built. I did not think to write down the numbers, thinking this is the only time I'll ever have to do this...)

    Then, I notice a hard spot on the middle position of the steering on my 4000 km :eek1 (that's 2500 miles !) '03 640 Enduro. I assume this one is dead as well - anyone comment on this ?

    Anyway, I searched the net to find an alternative solution (no way I'm giving KTM another 50 Eur for that), especially since I probably won't need to change the gaskets this time.

    Here's what I found out : 331274 is not in SKF's catalog anymore, and it seems it has been replaced by this : BT1B 328688 AC/Q

    I also found this which might be of interest.

    These are way cheaper solutions, but please remember : I have not actually tried yet to fit any of these, so don't take it for granted yet :deal

    If anyone has used any of those bearing on their KTM Lc4 (they all seem to have the same stem bearings), you are welcome to comment.

    I'll probably go for the SKF way, and let you know as soon as done.

    All the best

    Maniac
    #92
  13. bmwktmbill

    bmwktmbill Traveler

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    Manic,
    Just regrease the bearings on the '03. Nine times out of ten that brings them back to life. Just drop the whole works enough to wipe out the lower bearing and then wipe in some new grease, do the same up top but pull out the upper, wipe and regrease, tighten everything up and see what you have.

    Usually saves a total replacement. When that works and you are feeling good, pull the swing arm and regrease there(don't lose the rollers, I did), then do the pivot. Now pull the sprocket carrier bearing, pop the seals and grease it, do the same for the front wheel bearings working under the lip seals...can't remember if you can get at the rear wheel bearings???

    Change the fork oil, bleed the brakes, you are done.
    b
    #93
  14. KTManiac

    KTManiac Adventurer

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    Thanks bmwktmbill for your comments and advices.

    I did most of what you said, except for the swingarm thing...

    Now, about the stem bearing, I took everything apart and discovered the top bearing was quite ok, but the lower one was all rusty and could not be saved.
    As I said earlier, I ordered a pair of bearings from the SKF dealer :

    [​IMG]

    It cost me 15 EUR (21 USD) for both, and they fit perfectly ! That's cheaper than the KTM deal...

    Now, check out what was originally fitted on the bike :

    [​IMG]

    Not a very good picture, the left ref # is L45449, the right is L45410
    That's a polish made bearing, maybe this info is worth a search, for those who can find them. Odds are it will be much cheaper as well than the KTM price.

    All the best

    Maniac :1drink
    #94
  15. tineira

    tineira n00b

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    Just to complement this, I used Koyo L45449/10. US$19 for both of them.
    #95
  16. makazica

    makazica Been here awhile

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    Guys, I need to change the steering head bearings on a Husaberg FE 550.....is it possible to get the lower bearing out without a press??

    Thanks!

    M.
    #96
  17. KTManiac

    KTManiac Adventurer

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    Makazica, I used the method described here. Worked for me.

    Best,

    Maniac
    #97
  18. makazica

    makazica Been here awhile

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    Thank you very much.....very usefull!!
    #98
  19. DolphinJohn

    DolphinJohn Caveman

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    I'm going back and forth on whether to tear my front end apart to inspect/clean/replace my bearing.

    My bike is a 2000 Enduro with around 5k miles.

    I am planning to take it out to Colorado (in my truck) this Sept. for a month of riding, and want to make sure everything is good to go.

    I have the bike inside and with the front wheel off the ground the bearing seems real smooth. No notchyness, and moves real freely.

    I have other bikes to ride, lots of time, air conditioned work space......

    I was also planning to take a look at the swingarm/shock bearings too.

    Maybe I should have made this a poll???

    Any thoughts??

    .
    #99
  20. laramie LC4

    laramie LC4 flying something...

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    do them both just to be safe. the steering head bearing isn't as high a priority as the swing-arm and linkage. at 10yrs of age, i promise it's time to give it some love.

    laramie :beer