TM Sig 552 Disassembly/Reassembly & Upgrade Guide

kdouglas

Was going to post this over on my site but my hosting provider seems to be acting up at the moment (shameless plug hidden there, i know :P)

anyway, recently had the opportunity to strip and upgrade a TM Sig 552 belonging to Ample Free...? so i decided to take some pictures while i was at it and post them here with his kind permission

firstly, to start off here is the Sig 552 itself with the top part of the foregrip removed, and also the battery tray has been removed:



Remove the motor plate from the bottom of the grip by unscrewing the two screws either side, you can leave the allen key in the middle alone, this is the motor adjustment plate and unless your motor isn't meshing correctly with the bevel gear, doesnt need to be touched.


Once that's done, unhook the wires from the motor itself and remove the motor, watch out for the small metal disc on the bottom of the motor which will no doubt fall off and can sometimes stick to the side of the motor due to magnetism

next, have a look into the grip and you can see two screws which hold the grip onto the gearbox (brass here, but some aegs they are painted black and very hard to see)



Note the two motor wires go through the same hole in the grip


Fold the stock and remove the screw at the top pictured here


Then remove the two screws on either side of the body just behind the selector switch


the entire stock can then be slid straight off


On the underside of the selector switches is a small allen head grub screw, unscrew these halfway (so you dont lose them) and remove the selectors


underneath the selector is another piece which attaches to the selector gear assembly on the gearbox, unscrew these and lift them off, note that the one on the left hand side has a small spring and plastic piece which click into place when you turn the selector, be careful not to lose these. Also the one on the right hand side has a longer screw


Now remove the screw inside the mag well


And the two screws on either side (at this point you should have removed the bottom half of the foregrip too)


Next remove the screw just forward of the mag well


at this point you should be able to lift the upper half of the body forward and up away from the bottom half, note that it will be necessary also to remove the cable ties holding the fuse holder in place

kdouglas

The gearbox can now be lifted out of the rest of the body


note the position of the gears outside the gearbox which are controlled by the selector switch

right side


and left side


The larger of the gears will simply lift straight out, the small one on either side requires a screw to be removed on the left side and then slides out


Once you remove the gears on both sides, the black plastic piece underneath needs to be remove on the right hand side, simply pull it slightly down towards the trigger and it will unclip, underneath this there is also a small metal piece which sits partially inside the gearbox to block the trigger, unfortunately i havent got a photo of it, but you'll know it when you see it


This is the positioning of the selector plate and other components, you dont need to remove anything here, this is just for reference


Inside the gearbox with all the original parts installed


Systema High Speed gears, 1 Joule spring and metal bushings installed, also gears were re-shimmed



Now just stick everything back together in reverse order


The 9.6v custom battery being test fitted without the top half of the foregrip, note the position of the connector and the orientation of the battery with particular reference to the side which only has 2 cells




When the battery is correctly position as above, the only modification that needs to be made to the inside of the foregrip is to dremel away a little bit of the protruding area of one of the nuts/screws that hold the side rail on



and your done, this particular AEG now runs at a nice 19-20 rounds per second and has a nice crisp trigger response, havent had the opportunity to chrono it yet but with a systema 1J spring i would expect in the region of 300-300

ambro25

Absolutely fan-f*cking-tastic :eek:

I predict Interweb Fame for you and this page, never yet come across such a detailed/illustrated tutorial, only peeps moaning about what a b*tch the TM 552 is to disassemble.

Very, very, very many thanks, k

kdouglas

Yea, i did search online for a disassembly guide when I was doing it, but they weren't great, so I decided to take some pictures while I was doing it and make one myself

ambro25

Dredging this old thread up, as I've just ordered all the relevant bits to upgrade mine, and I'm about to take the DYI plunge following your comprehensive take-down, with:

* Systema (1J) spring upgrade
* Element 6.04 precision barrel
* Element 7mm steel bushings
* Systema steel shims

St Kdouglas of all things mechbox, pray for us

(KD, where was that 9,6V custom battery sourced from again?)

kdouglas

component-shop.co.uk they dont list it on their website, but if you email them they will make up the battery exactly how you want it. I just sent them a picture i grabbed off ebay last time, tell them shipping is to Ireland aswell and they will sort out the correct invoice for shipping etc...

ambro25

Ah, much obliged Sir! Thank you kindly

...and for my next trick, ladies and gents, the pint-sized AEG marvel that does it all: assault, sniping, support and CQB

Mac_Kaliba

ambro25 wrote: »

Absolutely fan-f*cking-tastic :eek:

I predict Interweb Fame for you and this page, never yet come across such a detailed/illustrated tutorial, only peeps moaning about what a b*tch the TM 552 is to disassemble.

Very, very, very many thanks, k

Indeed, I've joined this forum just to say the pictures have failed after stumbling upon this a month or so back on google.. The pictures were a very helpful reference but it appears the hosting site is down.
I've PM'd kdouglas to let him know and to congratulate on such a well written and helpful guide, like I said... +1 internets to the good sir at the top!

Cheers,
Mac.

josephhuynh

cannot see pictures bro. can you post it again please. thanks mate.

shytan

The thread is almost 4 years old check the dates before posting-Locked