Bearings or bushings

The gear set in your AEG is held in place by a set of bearings or bushings. Stock TM guns usually have nylon bushings, but with higher power springs it’s a good idea to switch to a steel bushing or bearing.







If you have nylon bushings, I would highly recommend that you swap them out for something better. High power springs or high ROF setups can actually melt the nylon. This can cause your gears to misalign and could potentially cause a catastrophic failure.

Personally, I run bearings in all my AEG setups. I find that because the gears are spinning on a bearing surface I get faster trigger response and a higher rate of fire. This happens because there is little to no friction in the mounting point of each gear.
If I had a dedicated DMR platform, I would have steel bushings and not bearings. High FPS setups put more strain on every component to your AEG system and one point that can get a lot of stress is the bearings or bushings. Using bearings instead of bushings puts one more potential failure point in your AEG. If your bearings were to ever break or blow out you could cause damage to the internals of your gearbox. Breaking a bushing is damn near impossible, and to this date I have never heard of a steel bushing breaking that is not plastic.
400 FPS setups= good quality bearings are ok
450+FPS setups= steel bushings.
(and of course this on only my opinion)
Bushings and bearings come in different sizes. 6mm 7mm 8mm and 9mm. Make sure you know what size your GB shell takes before making your purchase. If you have the option, go with the 8 or 9mm gearbox shell. Larger bearings are generally stronger than the smaller ones and are usually of better build quality.





If you want to squeeze a little bit more ROF out of your AEG or build a drop dead reliable setup, think about upgrading to steel bearings or bushings.


Cheers.

I try to use bushings (that fit good), bearings are fine for high speed, lower spring pressure, I am running a couple guns with bearings but that is the way the gear box came and these are CQB guns (350fps) I have had a couple sets of bearings explode running a Full auto AEG at 400FPS!

My thoughts come from the mechanical background, if you have a high load area, you need as much surface area to support that load, ball bearings,needle bearings etc do not have the contact area to support as much load as say a full metal bushing, you can use bearings to support high loads but that normally takes way larger bearings than what most AEG gear boxs have room for. if I could use any bearing I would pick needle over ball any day but again..no room!

one of these gear boxs was a drop in Systema, gears and shim checked, grease was good, ball bearing failed and took out the piston and spur gear, enlarged the bearing hole making a bearing replacement impossable!

no question all my DMRs run bushing and any gear boxs I assemble have bushing, never had a failure due to bushings and I do have a couple AEG's that will empty a mid cap in the blink of an eye and they run bushings