Sear's Hobby Page

Last weekend I decided to give my gearbox a once over and to show what it looks like after a year of use. Since I started using a lipoly battery, I wanted to see how the internals stood up after about 1500 bbs.





Left side of the gearbox. It still uses the stock cut-off lever and has worked without any problems. Normally, the semi-automatic function goes away pretty quick but fortunately, the lever showed no visible cracks or fine lines. By the way, the gearbox originally used plastic bushings, 7mm in diameter. This was strange since the G3A3 uses 6mm bushings. Like the cut-off lever, no cracks were seen. About the only problem is that one of the threads for the screws that join the pistol grip to the lower part of the gearbox has lost its "teeth" so only one screw works.  It's good to know that on the G3, the pistol grip also slots onto a groove on the back of the trigger guard.




The right side of the gearbox. If you look at the lower right, you can see a circular mark made by the bevel gear. I believe this is due to a worn shim and needs to be replaced. Also seen is one of the 7mm bushings. Despite the grimy look, it still in good shape. It's also worth noting that the hole where the bushing is placed is slightly tighter therefore when the gearbox is opened, the bushing stays in place. On the left side, I noted the same case for the spur gear's hole. Also included in the shot is the tappet plate spring, which has maintained its tension with no visible signs of stretching.



The Spur gear. From the picture itself, one can note wear at the edge of the gear just before the teeth. The teeth themselves appear rounded. I'm not sure if this is because if this has anything to do with the fact I stuck with the stock battery for a year and switched to lipolies simply because the I wanted to use stock components for as long as possible.


The Sector gear. The stock sector gear comes with a sector chip to control how the tappet plate is pulled during the compression stroke. The metal bushing is shown on the gear's axle. The marks are not from use but rather from times the gears were being aligned to their respective holes. Don't ask me how many times I've opened gearbox as I would classify myself as constant tinkerer.



The Bevel gear. This is the only gear that did was changed. Although not pictured, this gear comes with ball bearings on the left side of its axle. It came from my old M4 and didn't see that much use until I transferred it to the G3.  There are some slight marks on the teeth but not real wear or damage. How is this gear compared to one without any bearings? To be honest, I did not note any significant difference in performance.


Spring and spring guide. Originally I thought that the RAS model came with a metal spring guide until I remembered yesterday that came with a plastic version which I switched out the first time I opened it. The spring in the picture is a Guarder SP110. As I mentioned earlier, the G3 has gone through more than one spring upgrade. First it was a Tactical Unlimited 125, which gave the gun an average of 435 fps using the stock barrel and type 2 cylinder. At that time I was playing in the field with open fps rules. Then there was the TU130. I don't know exactly how strong this spring is. I once fired at Gatorade metal bottle cap at point blank. It made a hole though the bb did not go completely through. In some local airsoft forums, the TU130 did not get any stars as it was said that there were some issues regarding quality control. As I do not have any solid evidence to support or counter this, I won't go any further than what I have said. Suffice to say I have no problems with TU springs, they are reasonably priced and friendly on stock gears.


Tappet plate. Again no visible signs of stress or breaks. Same goes for the air seal nozzle. One thing I noticed when I first took the gun apart, the inner barrel and hop up assembly would move with when I slide the lower receiver out from the upper. I guess that means there is a good seal with no issues with air leaks.


Cylinder and cylinder head. After about 4 games, I switched to a type 0 cylinder. The original unit had a square hole. Stock fps using this and the original spring was at 380. Since the SP110 has already settled, I got 390 fps using the type 0 cylinder.