Gearbox keeps jamming

Discussion in 'Gun Building, Modifications & Repairs' started by E_2_, Sep 20, 2015.

  1. E_2_

    E_2_ New Member

    Hi guys. I am somewhat new to teching. I am in the process of trying to upgrade a V3 gearbox and am having some troubles. I am trying to replace the standard gears with a set of 13:1 low ratio gears and the stock motor an ASG CNC U-30000 high torque motor. Everything went into place flawlessly but, when I go to test fire, I get about 300 rounds through the gun before the gearbox just seizes up on me. I know my battery is charged, so I can't be running out of power. I have tried adjusting the motor height numerous times and it has never worked. The only thing I haven't tried yet is shimming the gearbox. What do you think is wrong with my gearbox?
  2. Lefse

    Lefse Well-Known Member Supporting Member

    You'll have to provide more info for us to figure out the issue. Did you shim the gears properly? What spring are you running? Exactly what battery are you using? This sounds like a typical underpowered battery to me.

  3. E_2_

    E_2_ New Member

    I have only been running it on an 8.4 volt battery, but the gun does fire for quite a while before jamming, so it's got to be enough power. And no I have not shimmed the gearbox yet. As for the spring, it's whatever stock spring is used in the umarex/elite force ump45 competition series (m110/m115 maybe?).
  4. kazuma5201

    kazuma5201 New Member

    A few things:

    1. Make sure it's shimmed properly. If you don't know how, google it. Tons of guides and videos on it.
    2. Make sure the wires haven't come loose from their terminals on the motor. Also make sure the Motor is secure and cannot move/turn in it's "cage".
    3. Make sure the internals of the Gearbox are SUPER clean and CLEAR of debris. The only thing making it fairly "dirty" should be grease for the gears.
    4. Inspect your Bushings/Bearings and make sure they aren't warped bent or broken. Consider better bushings/bearings anyways.
    5. Make sure you're AoE is correct. If you don't know what this is or how to fix it, google it as well. There are a plethora of guides and videos on it.
    6. Make sure you're gun is Feeding correctly. Make sure BBs aren't getting jammed between the lip of the airhop entry and the air nozzle. If the nozzle can't extend all the way forward for whatever reason, it could cause a jam, and even a gearbox malfunction. I'd advise installing a Sector Chip on your Sector Gear if this is what's happening.
    7. Inspect your Piston's Head and Teeth to make sure there aren't any damages; especially some really odd looking ones where it could be hitting something at an angle.
    8. What Spring do you have?
    9. What are the stats on your Battery and Fuse?