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GPX 250 Steering Head Bearing

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by SANZY, Jun 6, 2005.

  1. Hi All,

    I know it seem us GPX owners all seem to be having a problem at the same time but i still need some advise.

    How hard is it to replace the Stearing head bearing on a GPX250, i am OK with doing basic maintenace and have done mechanical repairs mainly on cars before so just want a feel for if it is a real pain in the arse or just a time consuming job.

    Second should i just get the standard Kawasaki replacement bearing or is there something better or a brand i should check to see if they make one. I just figure if i am going to do it may as well get the best i can.

    Thanks for the advise everyone.
  2. I'm not GPX knoledgable, but generally these things generally apply:

    1. The top one is pretty easy, but the bottom one will require heat and probably a puller.

    2. The items from a bearing company/supplier are identical to the factory, they just cost less.

    3. A lot of bikes have roller ball bearings in them. If you can find taper roller bearings, that are of the same size, fit them. They take much higher loads and don't pit as redilly. they will last much longer.
  3. Thank you for the feed back.

    I might have a look at the manual tonight and see if i think i can do this.

    Is a bearing puller expensive/ usefull to have.

    I don't think i have one at the moment but should have every thing else i need for the job.
  4. You can get them fairly cheap (bunnings? autowhatever?)and if your taking on these sort of tasks they are handy.

    I would however check that you can actually use one on your bike as the steering stem may get in the way. You may just have to use two large screw drives.

    You will reck the bearing getting it off not matter what you do.
  5. Thank you again for this info.

    Guess i should be able to get away with the screw drivers. At worst go for a quick run down to bunnings (glad i have a cage to help fix the bike)

    Now i just need to make sure we still have out torque wrench or else i will need to go shopping for tools.

    Any one done this job before on the GPX or ZZR (guess they are similar) I just want to know if i only need to order the bearings. Do the bearings come greased or will i need to get some for it?

    Sorry for the questions just thinking of doing it on the long weekend and don't wanna get half way done only to think, buger i need this little stupid thing to finish the job.
  6. Hey Sanz if you can afford it (not, probably why you're asking the question in the first place) get a bike shop to do it. If the job gets stuffed up, they have to pay to make it right before delivering it back to you. If you stuff it up, you pay twice to get the same result, and that could be more than they'd charge to do it once.
    These guys do this stuff all the time, and it will take less time too, plus, who wants to be out in a cold garage at 10:00pm at night wrestling with a steering head? (do I sound like I've done this myself????? sigh, too often)
  7. Have thought about a shop doing it and ran into one of the service guy's from the Kawa work shop i would use up the old road on the weekend and had a chat. I just think i could do it and save around $200 odd on the job and add this to the i have done this job once and never again pile.
  8. Some good advice already given above....
    Edit: try to replace existing bearings with tapered roller bearings from any bearings shop/ set about 30-50bux depending on size/ brand etc etc

    Just a few things:
    Be careful when doing up the triple-clamp-bolts, firm but NOT HARD, it's steel bolts into alloy... Usually 30-40nm if you have a torque-wrench, depending on bike/ check manual.

    While at it and having the forklegs out, change the fork-oil (if it hasn't been done in the last 2 years). Check weight in the manual or ask bike-shops/ newsgroups etc. (don't ask me :LOL: , don't know which weight goes for the GPX, but being **principally an older bike**, 10W is a good guess, speak auto-transmission fluid.

    You'll need a fairly long screwdiver/ steel-rod to slowly knock the bearing races out of the head-stock, just take your time, a couple of knocks one side then the other.
    Screwdrivers will bugger the dust-seal on the lower clamp, so will a cold-chisel etc.
    Shit myself the first time, but nowadays I'm used to taking a SMALL angle-grinder with a WORN metal-disc (down to about 5-6cm diameter), grinding *V*E*R*Y* carefully through the lower race until the material is very, very thin. Grinding disc sould be roughly parallel to the tube. Don't cut into the tube !! Once about 1/4-1/2mm thin, one half-hearted knock with chold-chisel and hammer cracks the remaining material, the race is easily removable after that.
    Cut straight through the cracked race with the angle-grinder again, remove the burs also with the angle grinder and use the old race to tap the new one into place.

    Freeze the new bearing-races wrapped tightly into glad-wrap to prevent too much moisture clinging to them while in the freezer, it makes installation easier. Of course, remove glad-wrap before installation. Grease the races and bearing-seat very thinly before tapping the races in.

    Grease up the bearings thoroughly, working dobs of grease into the roller-cages, spinning on a finger. Grease up the works again before installing the triple clamps.
    Giving it some effort, do up the adjuster-rings hand-tight, install forklegs, nip up the top-clamp bolts, install front wheel on a provisional base, loosely install brake calipers.
    Turn the bars. From center still-stand a light tap... and after about 10-15 degrees the front end should **take over and turn to full-lock under it's own steam** Then the tension is correct. Hard to describe, it's a matter of feel. Other say: tighten to about "firm", then loosen 1/8 of a turn.
    Whatever/ whichever.

    Do up the top crown nut/ dome-nut/ ring-nut/ whatever, check the top-clamp bolts again for firmness (see above), nip the bottom clamp bolts (see above), finish off the frontwheel/ axle/ clamp-bolts- installation and loctite the brake-caliper bolts with loctite 243 blue.
  9. Wow thanks Glitch_oz

    that is the type of info i was hoping to get so i now feel i can really do this. Just need to go and buy the bearing/race, grease and loctite now.

    Might see about the fork oil depends how the bank balance is feeling when i go to pick up the goods.
  10. Hey Sanz, don't do it before Wednesday, if the Homebush Bay Brewery ride is on, don't want to miss it.
  11. Bearings come with their race. A bearing is really 3 parts, an upper and lower race and the *movable" parts in between (either balls/ rollers or super-thin rollers called needles). Tapered roller bearings are better quality/ last longer than ball-bearings and their rollers are essentially one part with one of the races, stuck together by a "cage", a meshed metal thingo that holds the rollers in position.
    Loctite 243 will set you back about $10-13 per small bottle (blisterpack item).

    Take a loan for the $15 worth of fork oil, the time saved on the extra job is more than worth it. :) :)
  12. I will not be doing anything but riding the bike till monday (camping this weekend) so i am up for the wed ride. will do the fork oil but might pass on the loan. I have heard that 15W oil is the go for the front so ii might give it a go.
  13. Well, I have now otten the tapered bearings and the fork oil.

    Now all i have to do is wait till the weekend and do the work.

    Oh might have to duck down to the auto shop for some little things to before the weekend.
  14. Hi All,

    Just wanted to post up the results of the advise i got off of the forum.

    Over the last two days i have managed to change the steering head bearing on the bike ( still waiting to give it a decent tryout, no where good close to home) and also changed my exshaust for a ZZR250 setup i got cheap from a wrecker. the whole system including the two cans and the header was bought for the total cost of $175 from a local wrecker.

    I did not change the fork oil yet i might give that a go next weekend, i know double to work but i was just to worn out after evey thing else.

    so a big Thank you to all for your advise and help on the topic.

    Oh and i owe Glitch_oz a beer if i ever meet you, your resopnce was next to the work shop manual for me to reference the whole time. even had to crack out the angle grinder to get the lower inner race out (would not have tried it if you had not told me about it.).
  15. Sanzy, you are bucking for mechanical guru, well done! Great sense of satisfaction when you fix something yourself, and hopefully you've cured the clicking steering syndrome.
  16. good on you Sanz, for giving it a go
  17. Goodonya for giving it a go...and succeeding !!! Congrats !!

    :D :D First time around and it doesn't look like the right tool, eh? :LOL: :LOL:
    Sure does the trick, and many workshops do it the same way.
  18. Dam right it does not look like the right tool,

    It took me for bloody ever to grind it off, all i could think of is shit if i go to deep the race is going to not sit properly then i will really be up shit creek with out a paddle.

    But as a wise man once said slowly slowly the grinder will make the difference (or something like that).

    Now i just need the stupid rain to stop so i can give it a run in.

    Anyone from SYd up for a ride tomorrow night if the weather clears ?