Are some v2 gearboxes more stubborn than others?

[Nicky blue eyes]

I recently got a very battered JG m4. Internally the thing was covered in thick, black grease. Naturally muggins here decided to take it apart. I eventually get it back together but what a pig! The trigger kept coming out of place. Then I had to get the gears back in the bushings. Then the reversal latch kept coming out. Are all gear boxes this hard to put back or was it mr first timer here. Are there any tips to getting it to sit nicely in one side of the shell With out me swearing like an angry sailor.? Cheers 

 

[Prisce]

I know your pain. I have a JG m4 box I’m working on currently, and of course, one of the bushing holes has an imperfect cut, so the bushing doesn’t sit on it properly. Countless swearing and fettling later it’s sitting in a box ready to be put back together. 

I have only taken apart 10 gearboxes to date(so not that experienced) and every time I have trouble with the AR latch and the safety switch by the trigger. And then of course the sector gear decides to uproute the bushing and doesn’t sit flat.

I believe it’s one of those practice makes perfect things.

 

[Nicky blue eyes]

Its enough to make a man turn to drink. Lol. After all that hassle I don't want to take it apart again...until I realise I put the bugger back together wrong. 

 

[TARGETSZONE.CO.UK]

Ha Ha,

           Welcome to the world of being a tech. I am into the thousands and still occasionally get frustrated. Here is a few helpful tips that I used to do when I first started, but like anything yes it does become easier with experience. Get hold of some fishing line and some super glue. Put the gears in shimmed correctly(a whole different topic) also making sure the bushings are all seated correctly in the casings. leave the bevel gear out. Make sure the gear that drives the piston and moves the Tapet plate is in the position without the teeth at the top and that the Tapet plate sits comfortably. If your trigger spring keeps popping out then clean the little hole in the trigger and superglue the spring into the little hole once dried you should be able to fit the trigger without it popping out. If it still doesn't behave then the other end of the spring, try lifting it up and down in the casing until it sits still. Next your piston return spring should be fitted with your piston, piston head and nozzle in place (loop to the top on tapet plate fixing) . Put the mainspring in with tight coils to the back, but leave it loose don't put it under any tension yet. Back to your bevel gear. fit your anti reverse latch and pull it around clockwise as far as you can with one hand and insert your bevel gear with shim, then carefully release pressure on anti reverse latch if it sits ok then carefully move on to mainspring. If it keeps popping out then use the fishing line wrapped around the casing and over the bevel gear pulled tight to hold in place. This will put pressure on the gear which in turn will stop the anti reverse latch from lifting up. Next  Hold cylinder with right hand and put the mainspring and guide in place with the other. if you have the type of spring guide that is open ended then put a thin Phillips screwdriver through it from the back and down into the cylinder. This should hold in place for you. If you have the solid type then,  Take your left hand off but don't move your right. Moment of truth put casing cover on front end first moving your fingers carefully out the way whilst using your other hand to put pressure against the piston cylinder. Push the guide forward while putting pressure on the casing so that it sits ok at the top. Next poke the safety lever up into the casing maintain slight pressure on casing. Finally with a small screwdriver move all the gears and anti reverse latch around until seated correctly. fishing line and screwdriver out, Screws in job done. Just test that the nozzle springs backwards and forward freely, that the little spring is still in place on the selector plate on the other side and with a little screwdriver make sure the gears are turning freely(Until they become under pressure of the tapet plate) and make sure the wiring is seated correctly against the walls of the shell , so that the motor doesn't catch them. Hope this helps

 

[Samurai]

Practice.

For the cutoff lever, put a strong magnet on he outside of the gearbox where the cutoff is to hold it in place.

 

[Nicky blue eyes]

Just from the descriptions you gave me I recon I'm going to have to take it apart again. Oh well. Looks like I'll be getting a bottle of Jim  Bean to get me through it lol. Cheers

 

[Nicky blue eyes]

With the piston gear should the teeth be just on the pick up or completely on the other side?  Sorry if its a bit of a silly question. Cheers

 

[Sitting Duck]

What you should be aiming for is roughly this on assembly....

The sector gear has released piston and not just yet engaged the tappet plate

(so there is no tension at all in gears/drivechain)

BUT in this position the Cut Off Lever "might" still be raised slightly

WTF does this mean/matter - well that COL being raised slightly could impede the trigger working

The trigger's dead zone so to speak...

So don't get the box closed up and force the trigger if it feels a bit funny

You may need to carefully use a tiny flat screwdriver until the sector cam engages the tappet plate

(you will feel a slight bit of tension increasing as you spin the gears)

By this time the COL should have dropped fully and will slip into place & operate perfectly

DO NOT FORCE A STIFF TRIGGER IN DEAD ZONE !!!!

MAGNETS under AR Latch - brill idea from Samurai

I use 10mm x 2mm I think - one or two stacked under the box where AR Latch goes works a treat

buy on fleabay, amazon or dx.com if you can wait ages from china

(don't buy anything sensitive at same time as neodym/rare earth magnets - these mofo's are STRONG)

Alas - doesn't work on non magnetic/non ferrous trigger

if you epoxy bushings in your box I've dabbed a spec on trigger's tang eyelet hole to hold the sod

kinda cheating but wtf every little helps as Tesco says

most of the time you can get away with it

But if you got a pig of trigger & a mofo spring to fight with then last thing you want is trigger going AWOL

Well that is some of crap I/we might use, you find your own techniques/methods as you go

It gets easier the more you do, but in true honesty think we are all still learning as we go

 

[Nicky blue eyes]

Thanks I can do with as much advice as I can get. While I'm picking your brains I thought I'd try it all out, it works but its got a bit of a thump in the grip when it fires. How ever I can't remenber if it was there before