Derailleur Pulley Bolt

gummomarx
gummomarx Posts: 69
edited June 2022 in The workshop
Sadly, on trying to replace a pulley, the bolt head is stripped. Any tips on how to get it off?

Also, I'll need to buy a new bolt but I'm unsure, while searching online, what will be compatible with my Shimano RD-M663 derailleur.


Comments

  • Munsford0
    Munsford0 Posts: 678
    Drill it out carefully from the other side. Clean up the thread if necessary with a tap.

    Bolts are items 10 and 11 on here. Or search for the Shimano part number

    https://si.shimano.com/api/publish/storage/pdf/en/ev/RD-M663/EV-RD-M663-3043A.pdf

  • gummomarx
    gummomarx Posts: 69
    Thanks - I've sent for the drill bits. Fingers crossed.
  • MattFalle
    MattFalle Posts: 11,644
    Try putting a Torx bit in and undo it using that.
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • shirley_basso
    shirley_basso Posts: 6,195
    or a 12 spike torx bit also may work
  • MattFalle
    MattFalle Posts: 11,644
    shirley_basso said:

    or a 12 spike torx bit also may work

    Didn't MF say yhat?

    #dejavu
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • gummomarx
    gummomarx Posts: 69
    I'd tried that - no joy.
  • MattFalle
    MattFalle Posts: 11,644
    Flat blade screwdriver?

    Its mashed, so why not...
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • gummomarx
    gummomarx Posts: 69
    I'd tried that too.
  • MattFalle
    MattFalle Posts: 11,644
    Dremel a flat across the back and try and unscrew?
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • MattFalle
    MattFalle Posts: 11,644
    Can you also take another piccie from further back please
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • gummomarx
    gummomarx Posts: 69

  • gummomarx
    gummomarx Posts: 69
    I have a set in 0.5 increments - I think I'd need something in 0.2 steps.
  • masjer
    masjer Posts: 2,662
    edited June 2022
    If you remove the other good jockey wheel, you can use the (now loose) plate itself and unscrew if from the rounded bolt. Half a turn (of the plate) and the bolt will be loose. You might have to hold the bolt slightly, but they unscrew easily.
  • mully79
    mully79 Posts: 904
    oxoman said:

    I'm assuming when your trying to hammer the torch bit or larger allen key in that the back of the mech screw is up against something solid like metal or concrete. Woods to soft, had to show so many newer engineers how to do similar stuff it's unbelievable.

    Just watch you don’t pass them a VDE screwdriver they’ll think that makes them an electrician.

    If you suspect it’s going to be really jammed you can try a small pilot drill through the centre from the rounded bolt side. Then drill from the other side with a slightly larger bit. If your lucky it will bite and screw the bolt out with out damaging threads.
  • gummomarx
    gummomarx Posts: 69
    oxoman said:

    I'm assuming when your trying to hammer the torch bit or larger allen key in that the back of the mech screw is up against something solid like metal or concrete.

    This could be done with the bottom pulley bolt a the exit is visible but the top bolt exits into the derailleur body.

  • masjer
    masjer Posts: 2,662
    gummomarx said:

    oxoman said:

    I'm assuming when your trying to hammer the torch bit or larger allen key in that the back of the mech screw is up against something solid like metal or concrete.

    This could be done with the bottom pulley bolt a the exit is visible but the top bolt exits into the derailleur body.

    You can remove the whole cage from the main body. There is just a grub screw holding it on. Before you completely remove it, check the position of the cage, as usually there are 2 positions the spring lug can sit in.
  • gummomarx
    gummomarx Posts: 69
    masjer said:

    You can remove the whole cage from the main body. There is just a grub screw holding it on. Before you completely remove it, check the position of the cage, as usually there are 2 positions the spring lug can sit in.

    I'll have a look for that again before i start drilling. :D

  • masjer
    masjer Posts: 2,662
    edited June 2022
    Not the same as your derailleur, but this might help. Ignore the stuff about the top pivot. The part about spring tension and reassembly is probably what you need.
    https://parktool.com/en-int/blog/repair-help/rear-derailleur-overhaul
  • masjer
    masjer Posts: 2,662
    Like I said in my first post, once one jockey wheel is removed, you can use the plates themselves (a bit like a scissor action) to unscrew the bolt. It might save you having to use the drill.
  • gummomarx
    gummomarx Posts: 69
    Thanks masjer for your fine advice.
  • gummomarx
    gummomarx Posts: 69
    edited June 2022
    Mission accomplished, thanks to a combination of methods offered here and other forums:

    The new pulley bolt arrived today. I removed the bottom pulley and with the chain on the smallest sprocket, I was able to rotate the derailleur's outer cage plate after having removed the limiter-screw. This allowed the bolt to turn anti-clockwise enough so that, when I inserted the allen-key and put downward pressure on the tool, I managed to get sufficient bite into the bolt to get it fully turned and removed. Hallelujah!

    Thank goodness I didn't have to resort to drilling etc. Thanks also to the denizens of this thread for the inspiration, freely given, which spawned a solution to a tiny bolt with a big headache.
  • masjer
    masjer Posts: 2,662
    ^Good job, and thanks for the update.
    Just to say, it might be worth investing in a quality set of hex keys (if you don't already own a set) to avoid the dreaded rounded bolt.

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