G36 problems

[albawarrior]

Hey guys, I have a second hand G36 and I can't find any markings on it to say what make it is bit recently when I'm skirmishing she will stop firing. Sometimes just putting it on Full Auto will sort it but more recently it wont and it will only fire upside down!! Anyone heard of this before or think they know what's causing it?

[Sacarathe]

Have you tried more than one magazine?

[Sitting Duck]

stop firing or stop feeding ?

 

if intermitent firing - then its probably electrical, dirty switch/motor contacts/brushes

could be locking up - no offense sometimes people's first description is a bit off

hence some guesses also are a bit off too....

 

could be selector switch mechanism or cut off lever too - is the switch/trigger getting stuck

or feel different to pull (there is a "dead-zone" on the firing cycle sometimes)

 

if you can take some pics and upload to imgur etc....

(there is a sticky how to do this on here btw, how to upload pics etc....)

if we can guess the make then somebody might be able to chime in with some possible known qwirks on that gun

[albawarrior]

Its not a feeding issue. When you pull the trigger nothing happens. Hold it upside down and pull trigger and it works.

[albawarrior]

What would I be taking pic of? Just gun in general?

[ImTriggerHappy]

Its not a feeding issue. When you pull the trigger nothing happens. Hold it upside down and pull trigger and it works.

Sounds like a bad contact somewhere.

Take it apart clean all contacts and check all wiring for loose connections or damage.

[albawarrior]

I will take it apart and clean it. Will look for a tutorial. One of the guys at site today said cheaper g36s are known for this...... Was hoping someone might have heard of this and know a fix.

[Sitting Duck]

Take a pic, or two of gun.

Long story but some trigger switches have a copper plate on selector plate which must touch back of switch unit to complete circuit...

JG don't have this on G36's

Not 101% sure if cyma G36's have this ultra safe safety feature that can fail. But a cm515 M4 does.

SRC M4's also have this and it must contact the switch.

 

Probably ain't this but it is one part of circuit that "can" fail or be an iffy connection, etc....

 

Not being funny but I doubt if it is a JBBG one but if it was we would probably say no f*cking chance

 

If it is an Ares or Umarex it should have trades

 

So it could be a JG, Cyma, SRC maybe....

But you say in sig you have G&G.

Heck it could be an ICS.

 

Is there a screw underneath pistol grip ??

Could have TM or ICS on it or some thing....

 

If it is a certain length then not all makes do longer G36

 

So a PIC may help in more ways than you think

[albawarrior]

Ok will get pics up. I put G&G because guy I bought it off said it was but he obviously had no idea.

[Sitting Duck]

Dunno about G&G's but JG's have "made in china" on bottom of pistol grip

 

G&G's normally have G&G Armament in a few places on the guns - well M4's do

(and SRC, ICS & G&G are made in Taiwan btw)

 

could be a loose motor connector - holding it upside down contacts the loose motor terminal or something - still dodgy for shorting out

a pic might help to suss out make and that would help in checking out the exact same gun tear down vid on youtube etc....

[Carrel]

Sounds like the contacts for the trigger have gunkked up. Just clean them up and it should be fine

[albawarrior]

Ok so it says SRC on bottom of pistol grip.

[albawarrior]

Oh god....... It all went so wrong...... I need a gun doctor.... For the love of BB's what went wrong?!?!? I followed the video that SRC made and everything seemed fine. Now she wont even make a noise. Battery's are fully charged.

[Sacarathe]

Are you fully reassembling it before testing it? Or testing it with the gearbox out of the receivers, I ask because you can save a lot of time by testing things in bits.

[albawarrior]

I assembled the whole gear box and put it into the pistol grip.so basically fully assembled bar barrel etc.

[ImTriggerHappy]

Oh god....... It all went so wrong...... I need a gun doctor.... For the love of BB's what went wrong?!?!? I followed the video that SRC made and everything seemed fine. Now she wont even make a noise. Battery's are fully charged.

Haha can just see the panic. Shouldn't laugh but we have all been there.

[albawarrior]

Think I will take it to the local armourer 😜 there is a place in town that repairs and upgrades. Don't like having to pay someone to do it but would rather it worked since I was ripped off buying it!!

[Sitting Duck]

Motor polarity back to front

 

Piston slipped off rails

 

Don't worry my first couple of box openings did not go according to plan

(Massive understatement BTW)

 

The trigger AR latch mofo bastid mofo etc....

 

And if it was SRC you have my deepest sympathy

Their gears especially sector is $hit

 

Local techy or somebody who maintains ya site's rental guns is another option

 

Best of luck

[Ian_Gere]

I have an SRC G36 and she was OK out of the box apart from hop rubber...

 

Sounds very much to me as if you had an electrical fault, however, as Duck implies, at this stage it could be anything... I would encourage you to try to sort it out yourself - it's not your only gun, so you don't need it working right this minute, eh?

 

Examine the whole length of each wire for breaks in the insulation/crush marks/damage. Check that the soldering onto the trigger switch unit is intact and also that there is no short circuit between those contacts. Check that the motor connectors fit tightly and that the wires are properly attached to the spade connectors. Ideally you should cut those spade connectors off and solder the wires to the motor directly because that reduces the resistance and improves trigger response. Ideally replace the entire wiring with either 16AWG silcone wiring, silver plated low resistance airsoft cable, or just as good and much cheaper is Maplin 15A power cable.

 

Check that your battery connectors are functioning correctly by using small pieces of wire to connect between the contacts - if the motor spins with the ad hoc connection but not when the connectors are plugged together you'll know that is the problem. Best bet is to swap to Deans connectors anyway, whether or not the Small Tamiya connectors are working.

 

You should be able to tell if your motor contacts are the wrong way round because the motor will twitch inside its cage when the trigger is pulled but not spin. Of course, at this stage you may have replaced something inside the gearbox in a way which jams anyway, so the motor would twitch. The best way to check that you electrical circuit is working independently of the mechanical parts is to remove the motor from the gearbox so that you can see it spin/fail when the trigger is pulled (hold it tightly/clamp it down because otherwise it will jump and may damage something).

 

TBH i doubt if the original problem was caused by pitted/dirty trigger contacts because holding it upside down would not alter that.

 

If the electrical system works, or when you have fixed it, and the gearbox does not cycle once the motor is back in, then clearly the problem is mechanical. Take the barstid apart again being careful to do as little damage to the screw heads and threads into the gearbox shell as possible. As Duck says, check that the piston is on its rails properly. Also check that there are no missing teeth from any of the gears, especially the Sector Gear (the one which contacts the piston), and that there are no extraneous pieces of metal/crap jammed into any of the gear teeth.

 

While you have it open you may as well check the shim job: buy some SHS shims, select 1 of the octagonal ones and place it on the under/left side of the Spur Gear (the middle one) then select the copper ones and place 1 onto each gear axle so that it will always be on top touching your bearings/bushings; with the piston out close the GB and fasten it with the screws; check the spin of the gears - they should be very loose; push against the bearings/bushings to see how much side-to-side play there is in each gear - this will give you an idea how many and what width shims are needed; the idea is that the Spur Gear should be as close to the left hand GB shell as possible but bear in mind that there must be some clearance or it can rub the shell once the gears are under strain; you are trying to get the best balance between gears which spin freely and gears which do not move from side to side; always err on the side of free spinning.

 

When you are satisfied with your shim job, grease the inside on the GB shell with CT-2 Teflon Grease (search fleabay); put blobs of CT-2 on the gear axles between the shims and gears and also between shims and bearings/bushings. Put plenty of C-2 on the piston rails. Make sure there is a thin layer of grease in the troughs where the Tappet Plate moves back and forth.

 

Make sure that the Anti-Reversal Latch and its spring are placed correctly - it should be under tension pulling the ARL upwards into contact with the Bevel Gear (the one which meets the motor's Pinion Gear).

 

Make sure that the Tappet Plate spring is correctly fitted and that the Air Seal Nozzle is correctly seated in the U-shaped end of the Tappet Plate.

 

May as well also use the CT-2 to coat the inside of the cylinder and the piston head O-ring - this will improve compression/consistency of compression.

 

Edit to add: if you have any questions by all means post them here, but pics always help.

[albawarrior]

Wow thanks for that Ian_Gere !! I will take her apart then and look at it.