Hi guys,
After long summer of playing with the Velocity Arms VA36 (JG G36), I've decided to take a first swing at disassembling this gun, cleaning it, maintaining it, inspecting the interior for wear & tear and possibly upgrading it. I'll try to log my progress in this thread as I get these things done.
This gun has treated me really well and has never had a single jam, failure, misfire, or even mis-aim. I got it for $270 with one mag. The hop-up and feeding have been excellent the entire time -- in fact, since buying the gun I had not touched the hop-up adjustment even once. In spite of all the reliability and fun this gun has generated, the one thing I've always wondered about is the internals. I've heard a lot of horror stories about JG guns and was very curious what this gun would look like after a few dozen games and entire weekends of being passed around between various folks all firing full auto out of it for hours on end. After months of abuse, is this thing just moments away from a catastrophic failure? Is there a terrible surprise awaiting me inside ...?
There's a variety of information out there about the JG G36 and I was able to get it apart very easily with the help of a few sources (SHWELL11 on YouTube, and Evike's disassembly videos in particular are a good source. Mechbox currently reports as infected with malware so you should all avoid their tutorials).
The rifle comes apart easily, with a couple surprises. When taking this thing apart don't get confused by the missing screw where the hinged stock attaches. Mine was missing it, if your's is too then you simply won't need to remove it. Hopefully I can find an appropriate screw to use in this spot. A note about pins and screws on this gun: many of them come out very easily and I had at least one screw holding back the barrel assembly that had begun to strip. It may be worthwhile to hunt down replacement screws (and nuts) if you want this rifle to survive frequent disassembly.
Here's the gearbox and the grip removed from the body. It doesn't look like a million bucks, but feels solid. I was relieved to see the spring/piston appeared to be settled in a relaxed position. A ported cylinder is present to match with the G36C's short barrel (port is not visible in the photo, it's on the other side). The area around the port on the cylinder is a bit scratched up, but the cylinder feels solid (and heavy).
By removing the large screw out of the motor grip, tapping out the pin seen here on the left and putting the selector into semi (as well as pressing on the receiver button), the gearbox easily slides out. The gearbox is a heavy metal painted black. The wiring is a little thin for my evolving tastes but I haven't experienced any issues with resistance yet.
I was anxious to remove the motor cage from the gearbox so that I could get a look at the pinion gear. I've had so much trouble with pinion/bevel alignment with both my G&G and G&P M4s (as have my friends with their G&P M4s) that I've come to expect nasty surprises when it comes to pinion inspection. Happily as you can see above, the pinion's teeth look to be in great shape, suggesting good alignment with the bevel gear. Being inexperienced with the version 3 setup, I can only guess that maybe this has to do with the motor cage design.
On to the gearbox...
When I saw that little caramel mountain of goo, I let out a chuckle. Is this the secret to the ultra-reliable VA36? Probably not.. I'll be re-greasing this thing for sure. Overall though, the gears are in mint condition and I was very happy to see that none of the abuse had yet gotten to it.
A bushing is visible in this picture and on the left side of the gearbox, I can't tell whether they can come out or whether they're actually part of the gearbox. On the right-hand side of the shell, they come out rather easily and are metal. Which brings me to the right-hand side of the gearbox...
I don't know how I didn't notice this at first but when I looked over I laughed again. Awesome. I'll never run out of grease!
Back to the gears.
Removing the sector reveals that it is gradually polishing the surface of the cut-off lever to a fine chrome finish. Oh well. I was bound to find SOME skeletons in this closet, and at least now while I'm already in here, I'll actually have something more fun to do than just cleaning and re-greasing. On that note: I didn't find any shims in this gun at all, but it's been a remarkably quiet gun for the lack of shims. I wonder if the mountains of grease is how JG gets around the lack of shimming. In any case, it didn't hurt performance or reliability for a whole summer. Not bad.
Heading up north towards the spring guide:
I think I'll be replacing this with a metal bearing spring guide. In the absence of things to fix, I gotta pimp something out right?
Nozzle:
The nozzle is plastic, and has a nuclear-symbol opening rather than circular opening like my other nozzles. Perhaps this helps guide the airflow to the middle of the BB in the hopup chamber? While I'm discussing springs and nozzles, I might as well mention that this gun has chronographed a consistent 360fps at several games. I suspect the spring is probably an M110.
Piston:
The piston is in great shape and the teeth look to be in good condition with no major wear (the picture masks it a bit with all the grease). The spring seems to be attached to the inside of the piston, which seems odd to me compared to the other rifles I have.
Wrapping up, here are some goals for this gearbox:
1) Upgrade the spring guide, maybe the piston and piston head.
2) Re-grease and re-shim the gearbox to reduce the wear I've seen.
3) Rewire the gun for Deans as I continue to standardize on Deans-wired batteries across my collection.
If anyone has any requests for pictures, or suggestions for project ideas, I'm all ears. I'll try to post progress / updates here.