Contact Us (626) 286-0360 Store Locations
Extended Phone Support Hours 7am-7pm PST
Browse by Type or Category
Airsoft Season! SAVE 18% with coupon code: SUMMER2018 (Exclude MAP and SALE Items)

G&P Complete 8mm Reinforced Gear Box for M4 M16 Airsoft AEG (Configuration: Rear Wired / Small Taymiya / 340-400 FPS)

24 Customer Reviews

by Brian C. on 08/11/2017
"Very happy with this gearbox. Put it in my completely stock G&G Combat Machine. It did require a little work to get it in. I could have used the thinner wires that came with the gun, but wanted to use the thicker and more flexible ones the gearbox came with.

FPS: I have had it chronoed with 0.20 bbs. Came in at 330 fps. I have another completely stock G&G Combat Machine that comes in consistently at 350, so this is a little slower... but MUCH quieter and smoother. The trigger response is infinity better even with the stock motor.

I plan on switching to an M120 spring and high torque high speed motor. That ought to get me closer to the 400 FPS limit of my local field.
by matthew s. on 02/09/2016
"Got this for my g&g cm16. Dropped right in with a little snug fit. Had to do some wire splicing for the battery. The motor wiring is a little different so if you're doing this for your g&g then you'll also need a better torque motor and I'm investing in a more qualified handgrip too
by Carl S. on 09/30/2015
"This is a very nice and high quality gearbox. I would though recommend re-shimming the gearbox and putting new silicone oil and teflon grease inside it. In my gearbox the bevel gear was not shimmed properly at all. I would also recommend switching the motor connectors to the more universal type motor connectors. It also comes preassembled and is packaged in a box with bubble wrap around it.
by Rick F. on 06/18/2015
"First the bad. The battery connector isn't the most common size, so had to change that. Also the motor wire for ground is was too short to reach.

Good: Everything else! I am happily surprised at rate of fire. I didnt build this as a rof build but it is very good. The fps is strong and allows for good range. Feels and looks super nice in the gun and feels like it will last a very long time. Thanks to Evike tech for recommendation!
by Brandon D. on 06/10/2015
"Awesome gearbox. I already had it for about a year now and it's still going. A must buy..
by dan w. on 04/19/2015
"i bought 2 black ops vipers for christmas in 2013, one of them finally had trigger issues so i decided to upgrade the guts. this gearbox dropped right in, requiring only slight modification to the ORIGINAL motor connectors (i didn't buy a motor), the original 8.4v/800ma battery wouldn't turn the motor, but i had a 8.4/1600ma battery that i use for another gun and it works amazingly well. the diference is clearly visible with the naked eye, over 400FPS with .20 gram bbs. i lost the cool blow back and charging bolt effects of the viper, but it's well worth the 85 dollars i paid. it's really all metal bearings, super nice, well over 5000 rounds later and it's super awesome, extremely high rate of fire compared to the stock viper gearbox in my other gun. the only con i have is that occasionally the selector switch goofs up when going from semi to full out, and it locks you out like it is on "safe". but switching back and forth again fixes it. overall A+
by Marko V. on 06/24/2014
"This is a pretty good gearbox for the price but there are things that i would change if you are getting it

- The piston head is kinda weak and has a tendency to explode at high fps
- The spring guide doesnt have bearings it only has 2 washers that kinda spin but it is metal
- The Tappet plate and the selector plate are flexible but weak
- The cylinder has no ports so you need a long inner barrel

- The other parts that i didn't list above are very good and very high quality
- Decent shim job
- Deans
- Greased well
- Exelent compression no leaks at all (even though the cylinder head has 1 O-ring)

Overall would recommend
by Garett P. on 03/17/2014
"Amazing I m buying a second one it is perfect for just a drop in into any m4
by John N. on 02/24/2014
"Perfect drop-in gearbox! No better company than G&P

Fits perfectly for a custom build with other G&P products
~400 FPS, with little to no deviation between shots.
PERFECT air seal
Wired to Deans
G&P quality gearbox

A Little over-spin with a G&P Satan motor w/ 7.4v LiPo
by mike w. on 08/25/2012
"Awesome gearbox but g&p only make great products so thats what i was expecting. easy drop in, you'll have to smash one connector flat so it will feed through the little hole into the handgaurd . other than that no mods required. shoots at 380 fps with madbull 6.03 ,465mm. and element hop-up with systema bucking. perfect for local fields. thanks g&p and evike!
by Walter C. on 03/18/2012
"I bought this to replace my shattered stock TM box. I've only run it through one day of games but so far so good with a m140 spring I swapped in. Comes with ball bearings, good set of G&P gears (with sector delay), good trigger and trigger group. It doesn't, however, come with a ball bearing spring guide nor piston head, so you might want to drop at least one of those in. I also replaced my piston with a aluminum because of the m140 and did a custom wire job due to a mosfet. All in all a solid box and a great buy.
by David M. on 07/25/2011
"its great has lasted me for a long time now i get around 26 bps with it and so far (fingers crossed) hasn't given me any trouble as far as lock ups or gears breaking Etc. unlike other gearboxes have in the past. only one problem with it is that the gb doesn't settle right in the utg body its either too big or too small in some way so there's no safety. safe is semi, i dont touch semi cause it tries to flip back in forth between firing modes and on full auto its full auto so ur only real safety is your trigger finger lol. i tried takeing it out even and putting it back in the "correct way" push the selector plate on the gearbox forward and putting the lower reciever on semi didnt fix the problem. so aside from that the gb is great id buy another one in a heart beat except the fact that it only uses g&p motors unless u do what i did which was replace the clips so it can use standard and other brands of motors. but that requires saudering it.
by Matt S. on 03/28/2011
"Ok so lets be honest, All this for $80 Bucks is a STEAL. no doubt about it, i have seen just the gearbox shell go for about $60, so to get the rest for another 20 was great, including some of the external components.

The Good,
The gearbox with the 8mm bearings is very nice, the spring guide is all metal, the cylinder is very nice and gets great compression. the cylinder head and air nozzle are both metal and get great compression. although i did not need them, the external components such as the charging handle and the selector switch was a nice bonus. I don't know what the FPS was originally, but i popped a Systema M120 spring and it shot 435FPS!

The Not so Good.
now I have not personally had a problem with the G&P White Piston, i have heard of them being defective and lead to premature death, needless to say i replaced right away with the G&P Blue SR 25 Piston. i have used a set of G&P gears for 4 years and one of them failed, the axle snapped, i have heard of this happening with G&P gears. the wiring harness did not have the usual terminals to connect it to a motor, but that was easily fixed with a soldering iron and some elbow grease.

This Gearbox fits great in a G&P Body and shoots great with the G&P Hop Up.
Overall I am extremely happy with this purchase.
by John S. on 01/18/2010
"i must say this is a truly fantastic drop in gearbox. now normally i just build my own gearboxes for my guns from scratch but i had an opportunity to get this gearbox for cheap off of a friend who bought it for his ak-47 and let me tell you this is a great quality gearbox especially for the money i use a 25c lipo a turbo motor and a new madbull 110 spring and this is a great gearbox very high quality everything
by chris r. on 02/14/2009
"One of the best gearboxes on the market. i bought one to put in my classic army m4 and its shoots very nice. The gears are high quality and come with a sector cam pre-installed. It also comes with a very nice stainless steel cylinder head and the air nozzle is metal with an o-ring in it for a very good airseal.