Help with Gen 9 Gearbox

Hi, I recently decided to get my first gel blaster but was getting it part by part.

I took apart the gearbox to change the o-ring and after reassembling it the gears seem to spin a split second of the motor rotating and then just lock up. The plunger or nozzle gets pulled back and then gets stuck in place. I’ve tried reassembling it according to videos on YouTube and even swapped the gears out thinking it’s a problem with the original ones but it just keeps happening.

Any idea where I might have messed up? !


Did you put the shims back in the right spot?

I’ve had this happen before when I didn’t put the spring retainer screw through the buffer tube. As the screw and washer help keep the spring & retainer straight.

Did you notice the spring or retainer was not straight?

I would try putting the gearbox back into the receiver without the barrel on and try the retainer screw and see what happens.

Also is your battery charged?

I didn’t touched any of the shims, and I’m sure my battery is charged. The spring and retainer are straight from what I can see, also which part is the retainer screw?

Hmm. Have you perhaps put the motor wires on backwards? That would cause the motor to go in reverse and the anti-reverse latch is catching it and causing it to stop?

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I’ve tried putting the wired in reverse and normally, still not working. I guess I’ll go buy another gearbox and try running it completely stock to check if it’s problem with the gearbox or something else.

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Seems strange mate, especially if it was working fine before the oring install…
Hard to say without pulling it down myself. Hopefully you get it sorted.

Are you talking about an upgraded spring retainer? If not, where’s the spring retainer screw bud? I Notice it has a hole there but never came with a screw in the retainer.

yeah Sorry mate, I have an upgraded spring retainer and didn’t think about it when I made that comment.

Mate as @Ryan mentioned , it is very difficult diagnosing these issues without being able to see what’s happening in the flesh.
Is it possible that you may have a club or someone close by that could help you out ?


Turns out my problem wasn’t with the gearbox but the motor. Tried another stock gearbox and it didn’t work, swapped the gears to a 16:1 ratio set and it’s working now. Does that mean the motor was too powerful for the stock gears to work correctly?

You haven’t mentioned what motor you’re using and no I wouldnt suspect the motor would be too powerful.
The stock gear ratio is only 18:1 which is bugger all difference.

It’s one of these:

For $US995, that will be a low quality (counterfeit) motor… which could be your problem?