Seized Front Sprocket.

Discussion in 'Technical Help' started by West Cork Paul, Aug 1, 2019.

  1. No way can I get the fecking thing offo_O, it’s seized solid. Corroded to the shaft I guess:(. All suggestions as to how to unseize and remove it are very welcome please.

    459ED5E4-1655-42D3-B677-CE7F64976B7A.jpeg
    The bolt head you can see between the sprocket puller central screw and the gearbox output shaft is there to prevent the sprocket puller pushing down into the central hole in the output shaft, which it was doing:(.

    TIA

    ps. Judicious amounts of penetrating fluid have already been applied over days to the sprocket/shaft join.
     
  2. Heat, then douse in ice-cold water?
     
    • Like Like x 1
    • Agree Agree x 1
    • Thanks Thanks x 1
  3. Heat is your friend, but be aware of possible seal damage behind the sprocket
     
    • Agree Agree x 2
    • Thanks Thanks x 1
    • Useful Useful x 1
  4. I came across this on a motorbike forum ( might have been this one ! )
    But I made a note for future reference .

    https://htsuppliesltd.co.uk/product/innotec-deblock-oil/

    Supposed to be the best product ever for loosening seized parts ....
    they also have one which gives a " freeze shock " to break the hold
    of seized parts .

    Just a thought ....
     
    • Thanks Thanks x 1
  5. You may get a better (more square) pull by using 2 bolts in the sprocket holes and jacking more directly off the shaft? The 3 legged pullers can easily go off square and you end up stripping the puller thread - ask me how I know....
     
    • Like Like x 2
    • Useful Useful x 1
    • Thanks Thanks x 2
    • Useful Useful x 1
  6. Angle grinder.
     
    • Like Like x 1
    • Funny Funny x 1
  7. Don't use the tapped holes, they will strip out
    A hydraulic puller and a bit of heat will do it.
     
    • Useful Useful x 2
  8. If the splines are worn, they could be holding it on too. Put it in gear and tap the sprocket left to right
     
    • Agree Agree x 2
    • Useful Useful x 2
    • Like Like x 1
  9. as above, heat the sprocket only and let it creep to the shaft and check or douse shaft behind sprocket occasionally with WD etc bearing seal in mind. I'm guessing you are not worried about saving sprocket? after or as well as careful heating, a light to medium hammer tap on sprocket extreme towards engine alternating 12 oclock/6 oclock etc will definitely do it eventually.
     
    • Agree Agree x 1
    • Useful Useful x 1
  10. Cut a section out with a dremel. Had to do that a couple of times. Molypaste when you fit it back.
     
  11. I tried the hammer taps - well whackso_O - thinking that might break the rust seal but not yet. I'll try heating it as well. I've a new socket set and chain to put on so don't need to keep this one.

    I suppose this is karma as my swingarm pivot bolt slid out really easily with a couple of taps from a drift - and that was after 20 yrs of it being in there:eek:.
     
    • Like Like x 1
  12. I might have to do that if the heat and hammer doesn't work.
     
  13. With the puller pulling tension on the sprocket - tap the puller with a hammer to shock the shaft.

    If that does not work - and you can gain access - carefully using a cutting disc on an angle grinder cut from outside in - may be worth fitting something behind sprocket to act as a stop if you get pulled in.

    Then cut as near as you can -

    Then try puller again

    If that does not work - then use a chisel to split the sprocket... but the issue is the load is taken by the shaft for every impact... so important to cut as close as you can..
     
    • Useful Useful x 1
  14. Yes to that one !

    Back in the Brit bike days , I "invested" in a kit with a bunch of puller legs , or whatever they're called , in different shapes and sizes .
    And the puller " hub " had slots for various 2 or 3 leg setups .

    I lent it out some time ago , didn't get it back , and then I didn't chase it ....
    .... if that's any guide to how good it was .... :)
     
    • Agree Agree x 1
  15. I’m going to apply some heat to the sprocket tomorrow (although I can’t help thinking that’ll cause the sprocket to expand and tighten on the gearbox shaft) then start tapping the sprocket with a hammer to see if I can break the rust seal between sprocket & shaft.

    I’m also going to apply some Frost’s Rust Remover to the sprocket/shaft join and see if that’ll dissolve the rust.

    Failing which, Ill see if I can, with the Dremel, carefully cut through the sprocket so I can split it and get it off.

    I will report back.
     
    • Like Like x 1
    • Agree Agree x 1
    • Useful Useful x 1
  16. Got a puller on it at present but the more I tighten the puller the more the central bolt just pushes into the hole in the gearbox shaft:(. Nature’s welding has truly taken holdo_O
     
  17. Tie a tow rope round the sprocket, park the bike side-on behind the garage door, cut a hole in the garage door, feed the rope through the hole and tie the rope to the back of your car. When I did this, I mashed my foot on the accelerator hoping the massive, sudden yank would shock the sprocket from the shaft, but the bike ripped the garage door from its moorings, bringing it along, following the car as we careered down the road, at times with the bike, still with an up n over door attached, bouncing about 8 feet off the ground until I was able to stop. I'm hoping to convince the insurance company that my home was partially wrecked by a personalised tornado in the middle of the night. However, you might be luckier and the sprocket may just pop off with no drama..

    Good luck!
     
    #20 Borgo Panigale, Aug 1, 2019
    Last edited: Aug 5, 2019
    • Funny Funny x 6
    • Like Like x 2
    • Face Palm Face Palm x 1