Installation: M4 with V2 Gearbox (Video)

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Rich demonstrates how to install an INFERNO in an M4 with V2 gearbox.

Note: For INFERNO Gen 1, refer to this video instead.

Video transcript: all right so our patient today is the salient arms gray from EMG and we are going to go ahead and tear this down and get it ready for installation all right so everything’s disassembled we’ve got the gearbox out here all we’re going to do at this point is just assemble the gearbox as per usual and get rid of everything inside all right so got everything out everything we don’t need has been put away see we still have the trigger in the trigger spring we also still have the selector plate and the safety arm here other than that everything has been set aside if you want at this point you can go ahead and wipe some of the grease out of the gearbox if there’s a lot doesn’t really hurt anything generally cleans up the installation so we’ll go ahead and do that for that we’re just going to use a rag with a little bit of acetone on it worried about getting every last bit but just get majority of it out of there so it doesn’t gunk anything up make it greasy one step we do on all of our installations usually is not necessary but we do it just to make sure is if you have a selector plate here that doesn’t have the metal sleeve on it we go ahead and just chamfer that inside edge a little bit that engages this selector switch a little bit you can see I don’t even have to remove it from the gearbox all I’m doing is breaking that sharp edge so before we go ahead and install everything I want to talk about one thing we do that is not absolutely required but we do it on just about all of our builds um and that is put in alignment screws so I’m going to go ahead and put a couple screws back in the body here now what we’re going to do is we’re going to put in set screws on the sides of the gearbox that will sit in between the gearbox and the lower receiver here so with the alignment screws first thing you want to do is locate where you want them on the gearbox we are going to put them on these two raised surfaces inside the receiver here sort of on the front side of that you can see we have used to Center punch to punch a hole or a starting mark in the gearbox the one thing I will say with that is you have to be careful drilling through here it’s easy to come through on a corner or an edge on the inside and that if you’re not careful can break your drill bit be real careful you want to try to drill through to a spot that is flat on the inside surface as well for instance this hole here if I look inside that’s going to come through right on the bottom flange of the gearbox so I’m going to move it up just a hair all right like that and that should give me enough clearance that I don’t come through so we use 632 set screws for this I have a 760 fourths drill bit that you use to drill the hole and then we’ll tap it one pull it over and to the other side alright so we got our two holes drilled we’re going to take our 632 tap we’re going to tap those holes now we can take our set screws I’ll throw it in just fine you can see that the set screws are basically right across from each other I just eyeballed this I didn’t tried to drill at all as one hole we find that trying to drill at all as one hole I tend to break your drill bit if you’re not careful there are pretty much right across from each other which is what we want – they’re pushing straight across at each other and not twisting gearbox by pushing here and here there we go that’s how we do our alignment screws alright now as far as setting the alignment screws what we’re going to do is start out with we are just going to do it visually and basically set them so that they are the same length on on each side so that they’re fitting snugly in between the receiver there later on we’re going to go ahead and actually check the alignment once the unit is installed and make sure it’s set up perfectly and then we’ll lock tight those screws in place get them all locked down to the move let’s go ahead and take this back out and go ahead and put the system in the gear box alright so we’ll be doing the Spartan Edition here so we’re going to go ahead and put the electronics in we’ll note that we did remove this small stud that sits right here to the trigger spring stud we did remove that on this gear box we found that it made the the board sit in a better position most of the time that’s not really necessary often it’s just part of the gear box but we found the way the holes lined up on this gearbox it let it sit in a better position if we removed that small flat-head screwdriver we’ll take that right out we’re going to run our wiring down here and there’s some two options basically one is to do this and to run it through the center here in some ways that’s the easiest option because then you can just run your wiring right through the center of the grip if you are running your wiring alternatively you can run your wiring right here like the stock wiring however if you do that you can’t just run the wiring through the center of the grip because the section here will pinch the wiring up against the gearbox once you tighten it down so if you want to run it like this then you’ll need to take a dremel or something and open up the slot between those two so you can run the fitting through there and then slide it over so it goes through that hole and doesn’t get pinched we’re just going to run it through the middle so for this installation we’re going to be using the Gentoo inferno we will be using the Wolverine airsoft filtered grip line let’s go ahead and get that installed so now we can plug it into the electronics put it into the gearbox and the the air line in this case is just going to run out right the same way that the wire harness does so now we’re going to install the buffer tube adapter we’re going to take the buffer tube screw thread it in there set that in place right like so put our trigger back in gearbox back together we just reinstall all our screws always make sure that your wiring is not pinched so before we fully tighten this down I’m going to put one in up towards the front where there’s not really any wiring and I’m just going to put it in loosely to hold everything together and I’m going to check and make sure that no wiring is being pinched that everything is free and clear there go ahead and snug everything back down one trick will match mention here is some gearboxes studio variation in the manufacturers the buffer tube adapter stays in place more securely than others the GM P’s it says it’s and to stay in pretty well but if you find that it just wants to fall out of place a lot you can take say a small piece of foam or we’ve even seen people use packing peanuts sounds silly but if it works it’s not really silly and stick it in between the back of the solenoid here and the buffer tube adapter there just to hold it in place there in the gearbox so it doesn’t move around this kind it’s not really necessary but you might find it helpful on some gun you’re working on all right so we got everything installed in the gearbox here we got our alignment set screws installed and roughly adjusted at this point we would go ahead and test the electronics soon we can plug it into air pressure check it make sure that everything is functioning normally always a good idea before you put everything back in the gun if you hadn’t done anything with the alignment screws you’d go ahead and reassemble it normally at this point what we’re going to do is we’re going to go through the alignment process and show you how to do that more precisely make sure everything is locked down so we’re going to go ahead and install the gearbox back in the lower receiver and we’re going to go ahead and put our two pins through again checking the wiring you may be able to see here if I just pressed here my wiring is going to get caught by the pin so we don’t want to do that we want to push the wiring out of the way let the pin pass through on some gearboxes you can use the wire guide keep the wiring out of the way the GMP gearbox is the wiring guide doesn’t work for that application so I would tend to watch out for it I’m going to go ahead and put my front alignment pin in so I have in our lower receiver and if there’s a lot of play in it still you might have to put the grip on as well to pull things together in this case there’s not a lot of play with there’s alignment screws and the two pins and back things are pretty solid so now what we’re going to do is we’re going to take our barrel and hop up out of our upper receiver you’re going to assemble this lower receiver without any barrel and hop-up just like so now we’re going to use another barrel we’re going to slide it down in the far end and the muzzle end of the barrel we’re going to check our alignment as you can see the alignments pretty close it probably would be okay but you see the barrel is sitting a little more towards to the left side of the gun then the nozzle is so we’re going to go back in and use those lineman screws to straighten that up and get that just perfect so we’re going to pull it out and what we’re going to do is we want the nozzle to move towards the left side of the receiver I am going to tighten the screw down by a half turn and then I’m going to back the other side out by a half turn as well do it just right by the same amount you still should be snug there we go got it snug back up there’s no play now we’re going to put it back together and see how we did alright so after our adjustment we got it back together and now when we check barrel lines up perfectly was nozzle and we’re one last time the receiver off and I’m going to put a little dab of Loctite on those two adjustment screws now if this was a vibration heavy application we’d want to put the lock tight on ahead of time so it really got worked down into the threads as it is all we want to do is just you know keep it from moving during normal use so we don’t generally bother taking it all the way back out just put a dab on the outside it will sort of wick down into the threads enough that it won’t really budge during normal use and that way we don’t have to worry about getting this the threads right back in the same position after we take them back out now we’re all ready to go we’re just going to go ahead and put her back together with the grip installed we can go ahead and check now that our selector states are working correctly which they are so now that we got the grip foot back on the buffer tube back put back on we’re just going to do one final check that we’re still lined up which it looks good check out our more focused alignment video as far as how the buffer tube and grip work together to sometimes affect the alignment but in this case we just tighten the grip down then put the buffer tube on and we were we’re all set there so pop it back off one last time put our shiny new mock bolt in there slide it all back together should be good grab some air and test it out alright we are good to go so that was the installation process beginning to end I hope that was helpful showing how all the different steps work together and sort of the process we go through to make sure we get thing things together just right every time so drop us a comment be sure to give us a follow for lots more informational videos as well as product announcements and other good stuff from Wolverine Airsoft