Airsoft Tech Talk: How To Shim A Gearbox

[@cosmicdonkz]

Now that is what I call a tutorial:) after watching this I would feel confident in tackling this myself. Thank you very much :)

[@leostuntman]

cosmicdonkz yes I concur very well done mate

[@michaelbirchall2247]

10 years later. This is the best shimming tutorial I've seen!!

[@ICEY2548]

Very very well explained with a good camera. Finally, thank you!

[@theloosecaboose4858]

Such a detailed tutorial, inside of a gearbox used to be as complicated as cold fusion in my mind but your tutorials have given me confidence, thank you!

[@mosszilla5420]

can a vise grip or vise be used instead of screwing/unscrewing everytime to troubleshoot shims ?

[@theloosecaboose4858]

to truly get the pressure in the necessary parts I would screw it together, the process took me about 5 hours...

[@MrBeny127]

+TheLooseCaboose 5 hours? christ

[@jeffchung35]

guys think about what he's missing. He forgot to mention that your supposed to shim the bevel gear to the pinion gear. The pinion gear is a gear that can't be shimmed so you have to shim the bevel gear to the pinion and everything else off of that. Its just common sense.

[@baszt]

There are a lot of tutorials about shimming which are very good but this has something in plus. It gives you confidence. I was very sceptical about starting to do it myself but now I am faithful. It is somehow an out of the box view of this process. Thank you so much.

[@Coltonmatson]

What makes this video that much better is how explains what can go wrong if done incorrectly. Other videos lightly touch on the topic with almost a hand wave towards proper shimming, but this video explains why it's important to shim correctly, and what can happen if it goes wrong. It makes you pay closer attention to detail.

[@slowbbs]

No way this vid is 10 years old and still the best shimming tutorial.

[@FongDongSilver]

i wouldnt start with the spur gear. then its a hit or miss if the pinion is meshing well with the bevel. you always wanna start shimming bevel to pinion, the bevel to spur, then spur to sector.

[@nitemunky76]

+1 - start with the bevel gear and shim this to the motor pinion.

[@FongDongSilver]

motor height is far different than pinion to bevel shimming.

[@xdivineHART]

This is the best shimming guide I've ever seen.

[@TheRealDealAirsoft]

A lot of value in this video. It’s the real deal

[@mzjango]

Awesome video and a beautiful shim job sir :) . In order to test that Semi-Auto is still functioning after the re-shim, I like to leave the switch assembly and selector plate inside during a shim job. To do so you can pop the trigger in, tighten up a few gearbox screws around the shell. Push the selector plate to the semi-auto position and then pull down on the trigger. With the trigger depressed while also keeping the selector plate in place with a thumb or finger, you can then cycle the gears either with a finger or a flat headed screw driver. If Semi auto is working the gear rotation will come under some pressure (when the sector gear makes contact with the cut off lever); push past the pressure point and you will feel a click.. this is the switch block being flicked out of the switch canal. You can repeat this a few times to make sure it is working consistently.

[@VividEmotionPhotography]

you're videos are SUPERB. i appreciate the fact that you used proper terms, you didn't correct yourself, thus making understanding and learning this that much easier. THANK YOU!

[@simondcruz6915]

After 7 years still a very good tutorial Well done helped alot

[@darkknite385]

this was actually nice and informative i like your patience and how you tried to tell us almost everything and even told us the shims you use in a comment ive bought shims before from a retailer and i literally couldn't tell the difference between the "two kinds and in this video i most definitely saw the difference in your shims

[@pureforce56]

GREAT VIDEO! Planning on buying my first electric from Airsoft GI. Saw their rework prices. Its crazy how expensive it is. Im the type to tear all my stuff down to know how everything works. This video helped me understand shimming a lot.

[@SnipairBelgium]

the difference in tightness between setting everything together lose, and when screws are on is very very sensitive. That's why I would every time use the screws regardless. You'll have to try out with the screws anyways eventually. Now, mind you, I've spend a lot of time on this process all together. Of course I had not seen this vid before. So thanks a lot for this. and cheers

[@L3giT_Hax]

A good tip when getting shims for your build, get packs of ore measured shims. From one thou to ten should be plenty of range and you can really fine tune tooth engagement and the smoothness.

[@sagebrushhillbilly4655]

Best tutorial and explanation I have seen! Thank you, sir!

[@kn__-cl6nk]

Thumbs up! I only had 10 factory shims to start with and I think I still may need 1 more for on top of the sector gear, however it is still sounding much better than out of the box for my King Arms M4! Props to you bud. Thx!

[@vanilla.sp1c32]

Also, when you insert the motor and the pinion gear, that will have a tendency to push up the bevel gear slightly, so just make sure you factor that in when shimming.

[@sebus7628]

this is better than any of the tutorials, well done

[@michaelli8012]

Never had enjoyed a tutorial video like this, great work!

[@Neo_The_One_]

Thank you so much for this amazing guide! All question I could ever ask have been answered in this video.

[@LatinoSoulja1]

Thank you so much for making this tutorial! It was extremely helpful and you explained it very well keep it up!

[@CertifiedStepper]

Now this was a great tutorial im new to teching so i just put shims anywhere thinking as long as they're in the gearbox my gun is fine no wonder my bearings where so lose literally falling in the gearbox i might if even lost shims they're so tiny

[@TaZ101SAGA]

Great video. I've known for a while that my AK isn't shimmed properly, when I have the time I'll break it out with this new detailed instruction, thank you chum!

[@70mustang77]

Just wanted t say I enjoyed your video I have been working on guns for years and like to check out new video's because you never know when you might learn something else. Any way to my point this is one of this is one of the best I have seen in awhile. Nice work.

[@rock76222]

I practiced my first shim on this exact gearbox lol, it was a cruddy JG filth but it was super easy to shim

[@darkshock42mlg05]

This really helps. I'm shimming my sr25 because I blew a spur gear because I turned the hop too high and kept shooting it like an idiot. Something I already noticed about my gear set is my pinion and sector gear need way more shims than my spur gear because I only needed two 1 mm shims. One on each side. Assemble. I still have to shim the bottom part of the gearbox. There's no play and I will never have a side without a shim. Still need to put shims on the bevil but other than that the bevil to minion is fine. Makes the clicking sound you want.

[@julianpeter1768]

Very nice "How-To" ... even i (who never shimmed, cause i got modify gears in a cage;D ) understand in 10min how its work and shimmed a GB very well. Thank you for the tutorial. keep on going with that

[@Off2Fly737]

Thank you for taking the time to make that tutorial. Extremely well done and helpful!

[@gamervet1398]

thank you so much for the video im currently upgrading a lancer tactical fal carbine with a version 2 gearbox your videos have helped me a lot!

[@nooner203]

You should do a video on how to do the timing for the spur gear. That still makes no sense to me, but I know if you don't do it correctly then the piston won't do a full cycle.

[@KojirouHUN]

This is a most helpful video, thank you very much!!!

[@wyattdelancey2210]

Shimming is a art just like tech work

[@DRJ3k3l4321]

Probably the best tutorial I've see. I now know what my next project is. Awesome stuff thank you.

[@FreakSX93]

Very, very nice video. Now I realised my gearbox really needs (new) shiming!

[@jonobnz7597]

Great video. Picked up lots of tips. If you are ever in New Zealand I'll buy you a beer! Thanks.

[@EODhodge]

This video is outstanding! I love how in depth you go, and you're very clear and precise. Making it easy for someone whos never shimmed before. One suggestion: Add in the parts you use. Just throw in a little tab saying "G&G shims" or something like that. Speaking of which, what type of shims do you suggest, and where did you get them from?

[@CyAirsoft]

I love good ol' gearbox videos like this considering I myself am an airsoft internal junkie.

[@leonvaltchev2212]

I love your videos, they are so well articulated and explained. Thank you so much.

[@toy_shout6958]

2021 and I just found this page. Thanx 😊

[@soulathsaysanavong1007]

Superb guide man!

[@zoroxhun4035]

Very well explained tutorial, and nice video quality also.

[@CertifiedStepper]

I feel confident now i know what i need to look for to perfectly shim it

[@SteinerSE]

LOved this video, gave me confidence that I will be able to this for myself now that I'm moving onto AEGs. Only thing I'm missing is a bit on lubing/greasing things up when done for best result (or maybe you ahve other videos on that?)

[@isak_elof6987]

In the places where you got lucky, should you put the thinnest of shims wher none is needed just to minimice friction??

[@brutongaster8184]

Still a very good tutorial

[@ghost21rsst]

@ghost21rsst edit; Also having the gearbox tight with only gears in it, wrong! What about cutoff lever, trigger grouping, cylinder, and other parts that can cause the gearbox to flex further apart. This make work if you only have the gear-set, but the other items will make a difference.

[@Jay30001]

Do you think there was alot of friction with the gears when the gear box was bolted down because the gear box itself might have been a little warped due to use on the field, that would explain having a good shim job but when everything is bolted down some gears might have more friction than others? Very good video as well!

[@13conman1313]

Thanks so much this video I'm new to airsoft and I was able to shim my jg m4a1 gearbox perfectly. Keep up the videos. Could you try to do a video installing a MOSFET?

[@woodsks5885]

New to airsoft... getting a CYMA CM028. I want to attempt to shear those gears with this video.

[@joshs6535]

I feel like I'm listening to Mr. Roger's. Thanks!!

[@MrShapers88]

Awesome video. Thanks it helped me loads rebuilding my gearbox.

[@pbmig]

So do you shim with the cut off lever off? And then put it back after shimming?

[@damianbrener3813]

hi there!! i just bought a used TGM A5 and it came with a problem in the fire selector , when I shoot in full auto the replica keeps firing even if i dont push the trigger. it only happens when i go in fully auto , not in semi. Maybe that be a problem with the gearbox or something?? A friend of mine told me that the fire selector has a coil that can make contact with a plate and that may be a factory issue. Do you know how to repair it or can guide me to some videos that can be handy?? thanks a lot!!

[@gottenwheel14]

I fixed my gearbox that wouldn't fire in semi auto abd in auto it made a weird noise then stoped working so I opened up the gearbox which is a version 2 but plastic and I noticed the delay latch was off from when I stretched the spring so I had to place that latch in the correct spot and now it works in semi and full auto correctly and it sounds alot better plus I increased the fps slightly by stretching the spring this video is very helpful as it helped me understand alot more about aeg gearboxes I could make an aeg myself now but it would be cheaper to buy one and do upgrades on as it makes sence unless you get the parts for a good price

[@zaysef]

What would I also need to do different if I were to put a dual sector gear instead of the normal sector gear that comes with a gun by itself?

[@mathiasholmin7855]

I must say, by far the best shimming video on youtube! Thank you! Now I feel confident. :D

[@SomeAirsoftGuy]

Very in depth and helpful. Well done!

[@VividEmotionPhotography]

can the same type of shim be used on bearing vs bushing style gearboxes? and what do you do in the case of VFC gearboxes that have "auto-shimming" gears with the springs? Do you remove those spring shims in favor of traditional shims like this?

[@mikelkanygin5770]

Why you don't press-in bushings first?

[@kulpr1t]

When figuring out which gear needs re-shimming after you've torqued down the gearbox to test the gears, wouldn't it be much easier to leave the bevel and sector gears in and test both of them so you don't have to open the gearbox for each gear? This would allow you to figure out which gear needs re-shimming by bolting it down two times total instead of four.

[@Boba0514]

+CaptiousGaming I waa thinking about it, too.

[@tangozulu]

I have shimmed thousands of gearboxes. It is far easier although a lengthy process to put your screws in and tighten down with the addition of every gear. For example. Add your spur, shim, tighten down, test the spin! Add the sector, shim, tighten down, test the spin, Repeat for the bevel gear! Tho rest of the methodology of this video I would agree with.

[@joelfonseca8216]

What washers are you using? Like what material and what size.

[@joelfonseca8216]

I bought some nylon washer from ace. Would those be suitable to use?

[@dizzytricksta8451]

You should start shimming with your bevel to pinion gear first, then do your spur and finish with sector to guarantee optimal gear meshing.If you start with the spur then it's a coin flip on whether the pinion and bevel mesh properly if you shim to bevel to the spur.

[@HastagGotgamer]

Great video. Very thorough and very helpful.

[@ChezProductions7849]

Anybody no where o find a "sector shim"? I misplaced that little ring and am wondering where to get a replacement.

[@fordham366]

Cheers its getting me closer to reviving my mph5

[@CoveringFish]

Great video u deserve more subscribers

[@FongDongSilver]

you also wanna screw the gearbox together in certain areas so youll know for a fact when you tighten the shell together itll still be good.

[@lmJustGood]

I NEED some assistance/advise putting in an M170 spring. Me, my dad, and my buddy all working together trying to shove the spring in (just a few inches) to the gearbox can't get it in. Should I cut a few of the coils or not since this is a DSG build? Any help is appreciated. Thank you!

[@cyclotechtwister1997]

New to the game. Excellent and helpful video for myself. Proud owner of a brand new GSG 522 PK Full Metal AEG Airsoft Submachine Gun plane to do the ( m120 or m130 still undecided+other needed parts ) spring upgrade.

[@MrTGreat]

What's the inner Diameter on those shims?

[@schm147]

Would you recommend ball-bearing bushings for a high torque setup? Or would they wear out or break from that?

[@Hadden333]

This is a really great guide. Thanks for doing this!

[@filarce3400]

just use both hands on one screen at a time. slow, and steady wins the race

[@robcoscia80]

Helpful beyond belief. Thank you.

[@schm147]

Check out the "Monster" gearbox made by ModelWork. It's some radical shit.

[@sergioo__4788]

What area are you in? I have about 6 guns that I want to get upgraded with the basics. I tried to do some stuff myself and ended having to buy a new gearbox. Of course I’d pay to get stuff done. I just don’t have time to learn any of this stuff, even less time to do it.

[@charlesnelson224]

Where do you buy shims

[@c-dawg2145]

Where do i get shims?

[@rqairsoft4541]

SpeedSimmr You can get shims from any online airsoft website such as Evike, or you can even get them from Amazon.

[@c-dawg2145]

@@rqairsoft4541Thanks

[@Panzerlang]

Absolutely superb. I can't think of any way that could have been done better.

[@thomasbuchan18]

bevel to pinion is a better way, plus he shimmed the spur and sector too tight. Even in bushings they should feel frictionless and get multiple rotations with a low force spin. This method created a lot of stress on the bevel and pinion as the bevel being raised only .1mm forces the pinion to be too low and there is minimum contact that way. This also creates noise, when shimmed correctly all you should hear is a low pitched 'thud' from the piston head hitting the cylinder head, no other noise you typically hear in an AEG such as any high pitched noise

[@MrBeny127]

tried with my v3 gearbox. did not work. the cut off lever always makes the secor gear rub on it and slows the rate drastically of how my gears spin. i just put what i had together and took it to the local tech. he did an okay job considering i still hear gearbox whine. but im still using tamiya connectors and stock motor and gears. idk.

[@Dani98664]

What size screw driver did you use for those screws?

[@Vipera217]

I just tried shimming on an old gun and it took me 5 hours with a questionable outcome. It sounds unpleasant but i feel it comes from the anti-reverse latch rather than the gears themselves. The spring on the latch is quite strong and it may be the one making the "scratching" noise

[@markarato8034]

Did you lubricate properly? Most shimming videos don't tell you, but you should use some lube on certain areas.

[@Vipera217]

@@markarato8034 i didn't lube at all since we have none.

[@markarato8034]

@@Vipera217 You should get some gear oil from a hardware store and put a tiny bit on the surfaces of the shims. It should make everything sound a lot more pleasant, it can also eliminate any scratching sounds. After all, shims are metal parts that are in constant contact with other moving metal parts. They need some lubrication.

[@Vipera217]

@@markarato8034 can the gears' teeth be damaged from bad lube? i just replaced the bevel but it gave up after a game so im wondering if the bevel i replaced it with is old or it's due to it being dry

[@markarato8034]

@@Vipera217 moving metal parts being dry can cause issues as the metals scratch against each other. I would not lube the teeth directly, but you can and you should lube the shims and the bevels. Don't go crazy just use a tiny bit.

[@scotsman35p]

That was a very informative video, after watching it I'd feel comfortable enough to attempt shimming myself, i would say though it would have been better to know shim sizes instead of just thick, medium and thinner but can figure it out lol

[@dAirborn3b]

Is it fine, if I put a drop of superglue under the shims to help them stay in place so that when I want to take the gearbox apart for changing the spring i won't have to reshim the entire thing again?

[@AbandonAllLogic]

The grease usually hold them in place if you take it back apart.

[@Boogie4747]

hey man great video! seriously i learned a lot. thanks for posting

[@armando31665]

I have to say this is the best airsoft shimming video ever,

[@TheNervousPl]

Very good! Only thing you missed is height or motor

[@MediaLiveHD]

Well it's a good tutorial but still doesn't show how to shim the bevel to pinion and that's really important. All this doesn't help you if in the end the motor is pressing against the bevel or is way to loose.

[@TragicTry]

Extremely good video. Well worth my time. THANK YOU

[@HOLLISKID23]

Best tutorial ive seen!

[@MrKardukas]

Awesome tutorial! Thank you :)

[@Gattobuono]

Great video, very helpful, thanks. Subscribed :-) P.S. there's an annoying bass humming on the sound, had to turn my bass way down to be able to hear your voice.

[@USMILSPEC90]

yeah but you're still running a high risk of poping out the bearings and breaking them 8mm is definitely no and 9mm is a maybe but for sure is solid bushings.

[@MrCamil1]

Great video. Helped out alot thanks!

[@gapancha]

Best shimming tutorial on the whole KZbin universe!