I recently pieced together a m4 from various pieces, new and used. Well, mostly used, trying to get the most "bang for the buck" After scrounging most pieces it was time to decide on a gearbox.
SRC offers a complete gearbox for the m4 for 69.00 at JT. In stock form it comes with metal gears and plastic bushings. Not to shabby and probably would last a long time as long as it wasnt abused with too much voltage.
I planned on running 9.6 volts so I opted to have the bushings changed to metal and the top gear changed for insurance(Thanks Jerimiah) If memory serves this added about 15.00 to the price of the new gearbox.
As for performance, flawless! It worked great. Runs very smooth and shot 355fps with .20 on a stock spring. I am running a classic army motor/grip, metal body with a one piece hop-up.
So far I would say its a good and worthy purchase for the 70.00 price.
I will update as I put some hours on it and possibly further upgrades.
Pros:
Cheap
upgradeable
available
Apparent reliability
interchangability
metal gears
Cons:
Plastic bushings
Weak (supposedly) top gear
Now that I have run it a few games here are some updates on the box:
If you wanna run 9.6, install steel gears. I chewed up a Marui gear with my Classic Army BB motor and 9.6.
Upgrade the cylinder head or o-rings. When we changed the gear and cleaned it up the SRC o-rings lost seal. FPS dropped 50fps. They suck!
Other than a couple minor things, it still was a worthy purchase.
