G36 Problems

[Hux37]

I have 2 SRC G36Ks that I am having troubles with.

1) A customer brought it into Capital Airsoft as it was whining when shooting. After a tear down, it was found that the piston was stripped, the tappet plate was broken, one of the 8mm bushings was destroyed, and one of the gears was missing a tooth and the axle was loose and had lots of play. (read this as you can pull the axle out of the gear) All the parts were replaced with stock SRC parts. Upon trying to reassemble the mechbox it was found the tappet plate was binding.

I stripped the mechbox down to just the shell and tried fitting the tappet and see if it's function is impeded by any parts. It was found that the tappet was binding and catching on one of the cut outs in the mechbox.

The question for this is, could the mechbox have been warped from the factory to cause all this damage to the above mentioned parts.

2) Another SRC mechbox that we have completely rebuilt is having little to no compression. Where the highest fps was clocked at 152 fps.

The parts in this mechbox are:

Hurricane Gears
KA Half Tooth Piston
KA Tappet Plate
KA Selector Plate
8mm Bearing Bushings
SRC Stock Cylinder Head
SRC Stock Cylinder
SRC Stock Bearing Piston Head
SRC Stock Bearing Spring Guide

This box has been completely reshimmed, regreased, and rebuilt 6 times. We have tried it with different barrels, different hop up units, etc etc and it still baffles me as to how to get it to work right.

Any help would be appreciated. And if you need better descriptions please let me know.

Thanks,

Hux

[Ninja_En_Short]

SRC Stock Cylinder Head
SRC Stock Cylinder
SRC Stock Bearing Piston Head

Here's your problem, get rid of that crap and decent parts in there.

[Azathoth]

The shell could be off spec or the tappet plate.

Given the extent of the damage of the first sample I would guess that the gearbox is made from fail.

In the second case, are you doing a compression test before you assemble. If it's good then the problem is not inside the gearbox but how the nozzle gearbox interface with everything else such as the hopup.

My suggestion to the owner? Treat them like an out of date MAC. Toss it into the garbage and replace.

[Reckless]

I've seen a couple out of spec SRC gearbox's .. one even seemed to be 1mm short in over all length and was causing the piston to contact the bearing guide ...
that was a V2 though in an M4 ...


I've had a couple G36's on my bench too where the hop chamber wouldn't mate properly to the nozzle/front of the gearbox... causing a pretty decent airleak. a previous owner even went to the extreme of installing a M140 spring to get 360 fps... when I got the hop and nozzle/gearbox to line up and play nice, it wouldn't feed.. I had to file a path in the feed tube and base of hop unit (less then 1mm .. but enough to stop a bb from feeding) ... all said and done I had to go into the Gearbox too cause now it was firing 450+fps ... and the nasty spring had done some not to nice things to the interior of the gearbox...

[Jawz]

Hux,

I personally own two SRC-branded G36s: a G36E2 (2nd generation) and a G36KV (3rd generation).

From my experience, upgrading SRC v3 gearboxes is a major PITA (pain in the "Antarctica") because the gearboxes do seem to be out of spec. There's always some spot that binds! Some 3rd party pistons may not fit, then there are gears that do not mesh well, etc. and the ROF (rate of fire) obviously dropped noticeably to a point where the wires really heated up--meaning that too much amperage was running through the wires in order to cycle the gun. And BTW, we are talking about an ultra high-torque motor here!

What I eventually did was to replace both gearboxes with JGs--never had a problem afterwards! Those G36s run as smoothly as can be!

FYI, the same applies to SRC AKs! While they maybe externally very nice, it's the v3 gearbox again that raises my blood pressure! :banghead:

Anyway, good luck with your project!

Jawz