Diana Mod 34 - Diagnosis

[tyerant]

Hi all,

Please excuse my lack of knowledge of springers! I have only played with hpa and pcp thus far...

My Neighbor just brought me a Diana Model 34. Manufacture year is 1998. I think it is a T01 but not sure...

Any way, he said it worked fine until today. Now he tries to cock it and the sear won't catch. I asked him if he feels like it has the same tension but he doesn't use it enough to remember.
So when I break the barrel, I get no resistance until approximately 45 degrees. It feels smooth after that and has some tension. But I don't find it too hard to compress the spring.

This makes me think the mainspring is broken or bound up.

What do you think? Am I on the right track?

Any recommendations on how I can rig up a diy spring compressor to pull it apart? I was thinking of trying one of my trigger bar clamps from Canadian Tire. Would that work in a pinch?

If it is the main spring, any recommendations on where to buy a new spring? He only uses it one and a while and isn't all that interested in expensive mods.

Any help is appreciated!

[Normk]

A friend, who is familiar with that model, but who isn't a member, offered this response: "it sounds as if the spring has broken, for some reason not allowing the piston to rod to engage into the lock. The reason thinking is the little or no spring tension at the start of the cocking process."

He addeed the following: "If the spring is broken should be no problem however reassembly will require some jig to control the spring".

I can ask if he has a photo of the setup he uses to compress the spring.

[Rob27]

I have not worked on that gun so cannot tell you what normal preload is and since you do not have much experience with springers, caution is a good thing!
If you are not feeling any spring resistance until 45 degrees, that suggests that there is zero preload so no spring compressor will be needed to take it apart. The only exception to this would be if the spring broke and wedged in just the right way so that the back half is stuck and still under pressure while the front is loose - I doubt it, but it is technically possible so always use caution.
It does sound to me like a broken spring.
I believe that springs for this gun are available from the forum store.
You will likely need a compressor to install the new spring.
Rob27

[Dukemeister]

Almost certainly a broken spring, so you'll have to open it up to assess the internal damage.
Broken spring suggests it's been shot, likely a lot, so new seals would be a good investment when replacing the spring.
I have a 34 but mine is non-PAL. Over the years (well early years) the 34 had different diameter compression tubes, 26 mm and 28 mm I think. I know I bought a bunch of springs for my 34, and I believe mine has a T01 trigger... hey I must have posted about it here when I got it... let me have a look...Voila:
viewtopic.php?t=88223&hilit=Diana+34
So, mine is a first version, they were introduced in 1988 I believe. By 1998 your friends 34 may have a different compression chamber diameter than mine, so measure and be sure. A few pics may help us identify the exact model you have.
and here is a link to parts and a parts diagram:
https://twchambers.co.uk/diana-original ... -download/

You can use a bar clamp as a spring compressor, just be carful and point the business end (the rear) in a safe direction.
https://www.youtube.com/watch?v=4JQXmqa2Uj0&t=97s
HIH

[tyerant]

Thanks All!

I will carefully disassemble and see what is up. I had a feeling the main spring broke. Hopefully it didn't damage anything inside.

[lauchlin]

The mod 34 D in 22 cal is one of my favorite springiers i owned 4 or 5 of them and as with the model 48 D from about 1994 the spring in them seemed brittle and were prone to it snapping .I have no idea what Diana spring are like now i always used a after market springs loose a little power I got my spring here https://www.airrifleheadquarters.com/ca ... 099208.htm i am sure there is many others now .And i never used a spring compressor

[tyerant]

So I got it apart and the spring is shattered into 3 pieces, It doesn't look like it got bound up so hopefully the tube did not get damaged.

Since the gun is apart, I will likely replace the piston seal. I just confirmed my neighbor has his PAL so I can now shop for an appropriate spring.

I looked at the CAF store and can get a spring, seal and guide (his guide is a little worn) for just over $100 plus whatever shipping will be. It is a 28mm tube...

Should I spend a little extra and get a Tune Kit? If so, where would be a good place? airrifleheadquarters is sold out... A PG4 Delrin is about $50 more...

I would like to get the biggest bang for his buck without spending too much as he is not an enthusiast... Anything in-between?

Any links, suggestions, etc are welcome
Thanks

[Didd]

This tune kit is on clearance at D&L
https://dlairgun.com/products/diana-rws ... tuning-kit
Here’s a how to video
https://www.airrifletuning.com/fitting-a-tbt-guide-set/

[krawdad]

Here's a few more videos about tear down and rebuild.

https://youtu.be/df2byXywv14?si=Id6FNhkcvMk93T8S

https://youtu.be/5lY_LvKakxg?si=pbA-eTNllgDBH8hq

https://youtu.be/qf3vdqj6l9k?si=PqJlHZEkpY92vgSw

I have never owned or disassembled a diana model 34 so I don't have any experience unfortunately.

Dave

[lauchlin]

I would do this ( A PG4 Delrin ) you don't need a you tube video to fix it there was no internet when i was doing a lot of spring gun repairs and tune ..... don't mess with the trigger

[GLTRV]

I looked at the CAF store and can get a spring, seal and guide (his guide is a little worn) for just over $100 plus whatever shipping will be. It is a 28mm tube...

Should I spend a little extra and get a Tune Kit? If so, where would be a good place? airrifleheadquarters is sold out... A PG4 Delrin is about $50 more...

I would like to get the biggest bang for his buck without spending too much as he is not an enthusiast... Anything in-between?

Your cheapest option might be to buy a spring and seal from TW Chambers, skipping the guide: https://twchambers.co.uk/airgun-spares/ ... o1/?page=2

If your neighbor were an enthusiast, a tune kit would be worth it.
I've had a TbT kit in both my HW50 and Diana 280 (shorter stroke 34). While the cocking and shooting cycle was better than stock (less grindy and twangy), it was only about halfway between stock and a Vortek kit. I ended up swapping the TbT kit in both rifles for PG4 kits. "Thud!" is now the only noise these rifles make.
For the piston seal, you could also consider the Australian red or green "Custom Seal" (sold by D&L, Custom Seal and on eBay). The Vortek one is a good choice as well but $$$.