Slipping gears... Should I buy a new Gearbox or a new gun entirely?

[Vote4wes]

Hey all,

 

I've been playing around with my old Umarex MP5 which served me well for a year and a half until it started to fail on me.

So far I've been through a replacement motor, ripped the internals out and pulled pieces of plastic from the existing gearbox which had somehow gotten lodged in there (cure of plastic casing I guess).

 

Now the gun fires ok in Full-Auto, but on single shot, the gears are slipping and would end up jamming BBs and causing a mess.
I use single shot basically all the time on my other guns and... don't hate me, but I'm not always fan of full-auto as I mostly play CQB. 

 

Any of you pro's out there who've been through a similar ordeal, do you think its worth sticking with and getting a new gearbox installed, or should I cut my losses and get a new MP5 completely?

 

If there's any other fixes I could try to solve the slippages, then I'd be open to hearing about them. Either way I'll keep attacking it every now and again to see if I can revive it

 

 

 

 

 

[ak2m4]

if you're flush with cash then sure treat yourself to something new, but in general there's isn't a gearbox issue which can't be fixed with new parts and time etc.  Your problem could be a number of things, slipping gears?  ARL perhaps.  Best thing you can do is make a little video of it firing and another one with a look inside at all the bits

[EDcase]

JG do some pretty good MP5 models for decent prices and CYMA have metal uppers which are a bit more (if you can find one)

 

Obviously something got chewed up so best not to use it until you figure out where the plastic came from and where the slippage is.

Assuming you've already checked the gears have no wear and all the teeth are good on the piston, I would check the bushings and motor pinion gear.

 

Are you using 11.1v Li-Po by any chance?

 

Edited November 9, 2021 by EDcase

[JVacation]

2 minutes ago, EDcase said:

Obviously something got chewed up so best not to use it until you figure out where the plastic came from and where the slippage is.

 

Most likely a bb blockage causing the piston to chew a little bit

 

Is the Umarex the ones that are manufactured by VFC? if so the exterior wise you will struggle to find something as close to the real thing. Internals from VFC can always be a pain though

[leadly]

Hello Wes! 

 

I think you should HPA it!! You know it makes sense!!! Do it, do it, do it!!

[leadly]

It's OK @EDcase, Wes is the only one in our group without an air tank strapped to his back!  I'm working on him though!!

 

[EDcase]

Just now, leadly said:

It's OK @EDcase, Wes is the only one in our group without an air tank strapped to his back!  I'm working on him though!!

 

NOOOOOOOOOoooooooooooo............

 

[Shamal]

Haha. Well I guess that if airsoft don't work out for you then at least you are half way towards scuba diving. 😉

Regards 

[Vote4wes]

5 hours ago, EDcase said:

JG do some pretty good MP5 models for decent prices and CYMA have metal uppers which are a bit more (if you can find one)

 

Obviously something got chewed up so best not to use it until you figure out where the plastic came from and where the slippage is.

Assuming you've already checked the gears have no wear and all the teeth are good on the piston, I would check the bushings and motor pinion gear.

 

Are you using 11.1v Li-Po by any chance?

 

Thanks for your response, yeah I might need to strip the lot down again. I did use an 11.1v Lipo when testing actually... Think it's too much? 😁

[EDcase]

9 minutes ago, Vote4wes said:

I did use an 11.1v Lipo when testing actually... Think it's too much? 😁

Yep

[leadly]

Have you tried a smaller battery yet @Vote4wes?

[Vote4wes]

Right... a decision has been made...
I'm going to HPA it in the new year 😆

 

On 21/11/2021 at 18:12, leadly said:

Have you tried a smaller battery yet @Vote4wes?

Smaller battery, smaller problems

Edited December 10, 2021 by Vote4wes