The MG34 Repair and Troubleshooting Thread

[FirearmsEnthusiast]

Thanks for the info,keep it coming.
I have a firing pin, 2 firing pin springs (a replacement and a spare) and 2 trigger springs (for spares) coming.
I called Wolverine about getting spare parts. Waiting to hear back from them.
About the surplus ammo, will the lighter firing pin spring work?
Should I take a chance of firing another 480 rounds?
Is it worth it to pull that ammo apart and reuse the bullets (and powder?)

A couple of thoughts for you:
- I have a few spare parts on order with Wolverine, but they said that parts orders may never arrive due to export licensing issues on export of MG parts from the USA.
- With the exception of some bolt and trigger parts, original German parts can be used in many places.
- I replaced my firing pin spring with an original German one - much easier to cycle and #### the bolt. I fire handloads with CCI primers - 1-2 light strikes until the parts worked in, nothing since. I don’t use surplus ammo, but could be an issue for sure.
- I highly recommmend the .308 conversion kit - expensive but worth it in my view. Order from Irunguns. I used just the barrel and feed pawl, didn’t add the feed spacer, and it cycles fine.

Two issues from your previous posts:
- if 8mm surplus is cycling the gun hard, check your recoil booster cone. Many TNW guns use a 9mm hole in the cone, measure yours. If it’s 9mm, buy a 11-12 mm one - it is less violent in terms of initial barrel pushback and unlocking the action.

- I spoke with Brian Poling at BRP Guns and he has a theory that corrosive surplus ammo gets into the bolt rollers and corrodes the C clips, leading to loss of a roller and general chaos.

- spares- 2 sets of inner and outer bolt rollers, with C clip retainers for the outer roller; also maybe an ejector plate kit, and the 2 trigger rollers and pins for the trigger bar. Older MG34 conversions evidently only have one roller and much harder trigger pull.

- lubrication - remove the trigger group and lube both trigger rollers, then need to run free; lubricate both bolt rollers, the lugs on the bolt head, and the top and bottom of the bolt body. TNW recommends TW25B - available from Amazon.

Hope this helps...
Peter

 

[DILLIGAF]

TNW recommends TW25B

They cant even build guns that work ! How would they know what lube to use...lol. every single one of their parts has failed so far. its like I own a norinco FFS...

And drill your booster cone out to .450 for 8mm. It makes it much smoother .

 

[john442]

Dill...……
What lube do you recommend?

Cheers
John

 

[DILLIGAF]

Lube is a touchy subject, everyone has their favorite ...lol... I use Lucas high temp bearing grease and AFT fluid.

 

[1340]

Just so I get this right, the bolt (rollers, lugs and body) and barrel extension get grease? Trigger rollers also?
TIA

 

[FirearmsEnthusiast]

I would use TW25B or Lubriplate on the bolt rollers, lugs, and a light layer on the top and bottom of the bolt body.

I don’t grease the barrel extension directly...just let some transfer off the bolt lugs.

For the trigger group, I use Breakfree CLP as I want to lubricate the rollers but not use grease that may attract dirt.

Hope this helps.

Remove the bolt and initialize it with lubricant before every firing. Many of the failures I have seen posted about the TNW MG34 are from guys who took it out of the box, straight to the range with no initialization, put 300-500 rounds through it, and something breaks...

 

[Deathrawt]

Grease all that plus the parts of the barrel that slide in the bushings in the barrel housing
I also grease the cams on the barrel and reciever plus the barrel return plunger assembly in the reciever
The grease I use is called super lube and I get it from gregs distributing. It's really good stuff

 

[FirearmsEnthusiast]

Grease all that plus the parts of the barrel that slide in the bushings in the barrel housing
I also grease the cams on the barrel and reciever plus the barrel return plunger assembly in the reciever
The grease I use is called super lube and I get it from gregs distributing. It's really good stuff

Great advice from someone who knows his s*it about the MG34 - good point on the cams and barrel contact points...I do these less often but worth doing for sure!

 

[1340]

Gave my gun a good cleaning and lube today. Now I have a couple of questions.`
The trigger group only has the trigger (bar?), the spring and guide?
Also the ejection port is open because the dust cover is held open by the spring. Is that the way it should be?
TIA

 

[FirearmsEnthusiast]

Gave my gun a good cleaning and lube today. Now I have a couple of questions.`
The trigger group only has the trigger (bar?), the spring and guide?
Also the ejection port is open because the dust cover is held open by the spring. Is that the way it should be?
TIA

Yep - pretty simple trigger group - the complexity is in the bolt. Just make sure that the rollers on the trigger bar are free moving and lubed. Test trigger function after reassembly to sure that the rear roller can trip the sear on the bolt.

The ejection is straight down and you are correct, the port cover is held open by spring force, like an AR, and must be flipped closed after firing where it is retained by a small clip attached to the trigger group. German manuals reminded gunners constantly to keep closing the flap to keep dirt and sand out of the action to prevent stoppages.

 

[1340]

Yep - pretty simple trigger group - the complexity is in the bolt. Just make sure that the rollers on the trigger bar are free moving and lubed. Test trigger function after reassembly to sure that the rear roller can trip the sear on the bolt.

The ejection is straight down and you are correct, the port cover is held open by spring force, like an AR, and must be flipped closed after firing where it is retained by a small clip attached to the trigger group. German manuals reminded gunners constantly to keep closing the flap to keep dirt and sand out of the action to prevent stoppages.

Rollers are fine, lubed with CLP after cleaning.
I'll have to look closer at the ejection port. The cover stays open and doesn't appear to have a catch.

 

[FirearmsEnthusiast]

Rollers are fine, lubed with CLP after cleaning.
I'll have to look closer at the ejection port. The cover stays open and doesn't appear to have a catch.

The ejection port is retained by the small clip/wire which is part 117 in the diagram below. The long part of the wire protrudes forward of the trigger group and retains the rearmost part of the ejection port when closed.

Hope this helps...

 

[1340]

Very helpful, thanks.
I did notice part #117 in the trigger housing when I had the trigger group out.
I'll have to have a closer look.
Drilled the booster cone out

 

[1340]

I checked the dust cover retainer. The tab must be broken because there is nothing
sticking out past the trigger group housing.

 

[DILLIGAF]

Mine doesn't work either. Need to source a real one.

 

[1340]

Mine doesn't work either. Need to source a real one.

I've been looking, nothing yet.
The only place I found that had it listed, had it out of stock.
If you have more luck than me let me know.

 

[DILLIGAF]

gunpartscorp.com the shipping is so ridiculous im waiting until I need a few things before ordering.

 

[Deathrawt]

One of mine didn't work either until I used a small screwdriver and carefully pried the end of the small spring out a bit so it would catch the dust cover
Unless the spring is broken in which case it will need to be replaced

 

[Deathrawt]

Great advice from someone who knows his s*it about the MG34 - good point on the cams and barrel contact points...I do these less often but worth doing for sure!

Thanks for the kind words
When I first got my 34 I didn't know jack about how they worked and of course mine wouldn't even cycle one round before jamming and we all know what kind of warranty is on these (zero)
So I was pissed that I had a 5k wall hanger and vowed that I would fix it
I had zero help or knowledge of the thing so researched it heavily for months on various forums on the net. MG42.US is a good one with lots of info.
Once I learned about the mechanics I was able to figure out the issues and use various tricks that I read up on other forums and was able to get it to work properly. I bought folke myrvangs book about the mg34 and 42 and it helped out tons too.
A lot of the book is about the history and how the 34 came to be but there are chapters on the functions and the stoppages and how to fix them.
There is also a section about the tools for the gun and all the accessories that were available for it. It's a very interesting book and I highly recommend it

 

[FirearmsEnthusiast]

Thanks for the kind words
When I first got my 34 I didn't know jack about how they worked and of course mine wouldn't even cycle one round before jamming and we all know what kind of warranty is on these (zero)
So I was pissed that I had a 5k wall hanger and vowed that I would fix it
I had zero help or knowledge of the thing so researched it heavily for months on various forums on the net. MG42.US is a good one with lots of info.
Once I learned about the mechanics I was able to figure out the issues and use various tricks that I read up on other forums and was able to get it to work properly. I bought folke myrvangs book about the mg34 and 42 and it helped out tons too.
A lot of the book is about the history and how the 34 came to be but there are chapters on the functions and the stoppages and how to fix them.
There is also a section about the tools for the gun and all the accessories that were available for it. It's a very interesting book and I highly recommend it

Sounds like exactly what I did - I bought my -34 used and it was advertised as working perfectly...when the gun arrived the bolt was stuck forward, one of the bolt rollers was gone, and there were signs of lack of lunrication/heat damage on the trigger bar rollers.

After lots of reading on the forums and getting Myrvang’s book you mentioned, plus picking up John Baum’s excellent translation of several of the original WW II manuals from German Manuals, And sourcing parts from a great CGNner, eBay, Gunbroker and BRP Guns, my -34 is humming and I have learned tons about it. There is some amazing history about these guns...just check out the YouTube videos on the MG34 from Ian at Forgotten Weapons and Machine Gun Mike.