SACair Forum

Ok so today I replaced my gear box on my m4 with a systema shell. So as I took the gear box out of the gun I noticed that the bearings for the secotr gear and the bearing for the spur gear had well disentegrated. So I opened the gear box. As i looked at everything I noticed the my systema spur gear was fried, my piston was also torn all to hell.

i hear spellcheck helps.

ya u prolly shooda got a UTG. noob.

this is a question only snoopy can answer

I was talking to freq88 about that. He was saying that the a side load on the bearings will will waste them. I guess from improper shimming or just over time. Anyway that is what he said because we talking gearboxes and the benefit of bearings over bushings. I think I am staying with bushings.

[quote="rap1171"]

not sure, it was a stock TM shell. I always have trouble telling the diffrerance with bushings and bearings. Right now its a got a systema shell and 6mm bearings cause i just replaced all of that.

[quote="rap1171"]not sure, it was a stock TM shell. I always have trouble telling the diffrerance with bushings and bearings. Right now its a got a systema shell and 6mm bearings cause i just replaced all of that.[/quote]

[quote="snoopy"][quote="rap1171"]not sure, it was a stock TM shell. I always have trouble telling the diffrerance with bushings and bearings. Right now its a got a systema shell and 6mm bearings cause i just replaced all of that.[/quote]

[quote="tommyknocker2121"][quote="snoopy"][quote="rap1171"]not sure, it was a stock TM shell. I always have trouble telling the diffrerance with bushings and bearings. Right now its a got a systema shell and 6mm bearings cause i just replaced all of that.[/quote]

[quote="snoopy"]

Unfortunately, the actual sizes of the ball bearings in the 6mm, 7mm & 8mm bearings are itty bitty almost like a grain of sand. The side walls on the bearings cannot handle lateral stress of high ROF and or high spring rates. Heat is a definite major contributing factor. Also due to their sizes their lifespan is going to be short also. The shielding on the bearings probably gave way which lead to a chain reaction of the ball bearings just getting eaten up which got into your spur gear and piston.

ya thats what i was thinking. I replaced the gear box just cause. Right this is what im running in the gun.

I just don't trust the monkey metal that everyone uses ;)

who does, so what do u use?

you should know what I use. But personally I prefer bushings over bearings. Though I know 7mm bushings are next to impossible to find.

6mm or 7mm-doesn't really matter why it failed.

TM nylon bushings and M100 springs. Winning combo.

[quote="neouser"]TM nylon bushings and M100 springs. Winning combo.

[quote="neouser"]TM nylon bushings and M100 springs. Winning combo.

[quote="Ray"][quote="neouser"]TM nylon bushings and M100 springs. Winning combo.

Oh yeah!!! Sorry about that. I was in between jobs at the time.