G&G PM5 Broken Spur Gear

[Superstuco]

Hello All !

I bought my PM5 g&g at velocityarms a few months ago... Had a blast with it, shot over 15000 shots with it without problems... Then the other day, SCRRrRrrrRRCCRCRRRrRR. I stopped shooting right away. It's that kind of noise that makes you feal bad for the gears...

So I started looking for videos on the web explaining how to open the gun and proceeded to dissassembling it. Wow. It WAS a broken toth on the spur gear. Makes sense.

I found a systema spur gear on 007airsoft http://www.007airsoft.com/products/htm/upgrades.htm for 38 bucks canadian... will this fit with my gun? Is this a good deal? I intend to learn how to fix this baby when it breaks to not be dependent on the few dudes around where I live that know how to do it...

Also, i'm wondering how the hell will the wire that passes through at the bottom of the gearbox resist the friction of the motor's head! I mean, it does not seem to make sense that the motor spins like crazy right on the dam red wire! Is this normal?

So do you guys have any advice for me? Should I order this? Anything else? Do i really need that gray grease for the gears? Thanx !

[theguy]

hi?

Buy a new spur gear?

[yuhaoyang]

Depends on how well the gear teeth match (potential engagement and backlash problems), what ratio is the gearset and the one your looking at, and ect.
You may want to consider a whole new gearset, and since this is the first time you've opened a gearbox, you may want to take it to a gun doc for shimming, rather than do it yourself, or shell out $100 for a modular gearset+gearset key.

[DefCon 1]

Be careful when re shimming the mechbox. It's really important that you take your time as it will cause you all sorts of headaches if not done properly.

I think Mechbox.com have a video on shimming.
Anyway, good luck

Cheers

[m102404]

It's usually not recommended to mix & match gears from different manufacturers/sets/wear. Even if you find the same make/gear ratio...your other two gears have "worn in to" the one that is now broken.

The safe recommendation is to buy a complete new gear set. Expensive, but "safe". The PP Systems gears (airsoftparts.ca) are really nice for the price. Modify gears are great too.

When the motor is installed...the pinion gear (the one on the motor shaft) is above the wire and not touching it. You can test fit the motor while you have the mechbox open like that...and see where it sits.

You can also run the red wire tucked in closer to the bottom of the mechbox...to make sure it stays out of the way.

Best of luck with the shimming,

Tys

[Superstuco]

Hey Guys! Thanx for the replyes...

Ok so I'l order a full set of gears... I'm just wondering... The gear sets are almost all said to be "high torque" or "high speed"... I'm basically just looking to get exactly what I had before... The original parts from my G&G PM5A4. So... What should I choose? High speed means I have to get a different piston with smaller teeths? That's what I don't want as of now... Now much cash available for gun parts...

And for the smimming, I found a couple of graphs on the web that show what thickness shims to put where... I'm gonna try it, need to learn eventually anyway... What's the worse case scenario for a shitty shimming? Jams? Premature wear? Teeth exploding when I first spin them?

[Styrak]

Just don't get gigh speed or high torque. Look for regular ratio gears. If the ratio is listed with the gears I believe standard is 18:1

[m102404]

If stuck for choice, I'd default to torque up gears.

I'm sure you can do a simple search for shimming...there's search fields and buttons littered all over this site.

Google "Devgru shimming guide" ...it has great pics and comments on key points. There is no magic "use this shim here or there" formula that works for every setup.

Search, research and you'll figure it out.

[yuhaoyang]

don't use that "put these shims here" diagram