LCT AK: Internals Review

I’ve owned this LCT AK-104 AEG with LCT AK-105 receiver and stock hybrid (technically a AKS-105) since at least August 2012 – just shy of a year since I brought home my LCT AK, I think I’ve had enough rounds fired through this gun to do a decent review of the internal build quality of an LCT.

I’ve since thrown on a few different parts to the externals, though the internals, magazines and batteries have all remained the same since my last after-action review. Changed internal parts that I’ve been running are: Madbull 363mm 6.03 Black Python II barrel, Systema hop up bucking, Guarder 70-degree black (hard) hop nub, and Cyma torque motor out of my very first AK from years ago.

Reliability-wise, I’m very impressed with the gearbox. It hasn’t actually failed me as of yet; it was pretty much my only go-to gun from late Fall of 2012 to early 2013. The spring has slightly compressed from the 400 FPS mark on a 0.20g BB I chrono’ed it at in December 2012 to the 376 FPS mark on a 0.20g BB, though the consistency is still up there within about 3 FPS deviance. I did just open up the gearbox and clean/re-grease it after doing that chrono test, so I’m actually not sure if muzzle velocity and consistency may have gone up a bit.


More on the condition of the various internal components with pictures after the break.

Gears are in good condition, and 6mm bushings in a V3 gearbox are pretty much indestructible. Anti-reversal latch holding up without any serious signs of wear.


Piston with full rack of steel teeth is running well, considering the fact that I’ve had no jams with this gun it hasn’t had a chance to tear my gears apart yet. No wear that suggests that I should replace it any time soon.


Switch assembly contacts are in surprisingly good condition, despite use on 60% semi on a Firefox 11.1V 1200MaH 20C thin stick lipo. Only been recently that I’ve been running long strings of full-auto through this gun, after getting a couple of APS AK high caps gifted to me by Julian (“Optix”) and grabbing some from the missing demo/rental APS AK’s from work. Reason for the usage of APS AK-74 high capacity mags is the fact that they fit really well in the LCT AK, even better than in APS’s own AK receivers – they don’t feed as well as other high caps I’ve seen in use that feed through most of the magazine, but they get the job done when I’m feeling like raining plastic down on people at Ambush.


Note – this was not included in my previous write-up on the LCT AK internals in December: LCT has hot-glued the wires in the Tamiya small-type battery plug in place, hence no failures in regards to a lack of power due to 1-2 plugs in the connector coming loose from the plastic housing.


Some build up of gunk here and there within the cylinder, though nothing unexpected as the stroke of the piston is bound to draw in some grime through the 3/4 port cylinder. Cleaned and reapplied cylinder grease.


Cylinder head rubber bumper is becoming a bit loose though, glued it back on there though I probably didn’t give the glue enough time to dry before testing the gearbox to make sure that everything was assembled back together correctly. Probably a result of repeated poundings of the LCT metal piston head against the bumper in both cold and warm temperatures as the seasons changed.


Tappet plate and air nozzle are still holding up fine. No warping or cracks that I can see.


Spring guide is plastic, though it hasn’t broken yet, I did decide to swap it to a metal one I had lying around. No bearings though, bears require lube and may break… I probably won’t open this gearbox for at least another 6 months as it hasn’t given me any reason to since I first picked it up.


Honestly, the only problem I’ve had with this gun is that it occasionally doesn’t respond on semi-auto. Trigger pull will result in clicking noise similar to a locked gearbox, though gearbox itself doesn’t seem to be locked when I disassemble and check everything out. I believe the issue to be a result of the interface between the cut-off lever and selector plate (selector plate has some extra give where cut-off lever rides against that I haven’t seen in other AK gearboxes). This being said, the cut-off lever itself is still in excellent condition.


I did do a slight modification while my AK was in pieces this time – I installed a new hop up bucking (the A Plus Devil bucking requires a barrel with a larger hop window, so I had to change my barrel as well). I’m currently testing the A Plus Devil hop up bucking (Gen 2) with the King Arms M4A1 stock brass inner barrel. It feeds fine thus far, though I’m not sure how its shooting at range as of yet. More on this will follow if things go well this Sunday.


4 responses to “LCT AK: Internals Review

  • Rob

    How is the LCT holding up, 3 years on? What did you have to replace?

    • juicy

      Had a few stock LCT gearboxes that had catastrophic failures – all received different motors & hop up buckings ASAP.

      One broke a piston body, causing the gears to jam (piston rack was still OK – I was curious & took the plastic piece out before reassembly as is & the piston still cycled for a few trigger pulls in both semi & auto. Obviously replaced the piston immediately after, but it did work).

      One had a catastrophic bushing failure – previous owner had dragged this older LCT through a gravel pit? parking lot? or something along those lines in order to attempt to create some more natural looking artificial wear externally (SMH) – a small chunk of rock got lodged between the spur & bevel gear causing the gears to lock. This resulted in the bevel gear bushings giving out – the gear shafts were no longer straight, but the teeth on both gears were still intact.

      My very first LCT has seen fairly significant internal upgrades – all that remains internally is the original LCT gearbox shell, cut off lever, gearbox top plate & assorted screws, selector plate, and hop up chamber. The last stock part to fail in here was a worn tappet plate. One of the earlier failures before the last few upgrades was the switch contacts burning out.

  • manuzorch

    Hi buddy,
    I know this is an old post but as a pleased owner of an LCT 104/105 I really enjoyed reading it.
    Furthermore this particular sentence made me react: “Honestly, the only problem I’ve had with this gun is that it occasionally doesn’t respond on semi-auto.” I have exactly the same symptom on mine! Since i am far from being as “techy” as you are, I am glad to find a possible reason here ^^
    Cheers for the work done here & greetings from France

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