Diana T05 trigger (and clones) re-assembly with pictures

[happymecanic]

This is a re-assembly tutorial for the Diana T05 trigger (and its clones - Ruger Blackhawk, etc). As far as I can tell, all these triggers are configured exactly the same, so the same procedures and principles apply to all. I won’t cover the disassembly and tuning/lubing of the trigger in this thread, only the re-assembly with ‘’dry’’ components.

I’ll be using my Ruger Blackhawk T05-clone trigger as an example. The main differences with an original are that the trigger blade is made from metal, and the stock screw nut is removable. On the original T05 the stock screw bolts into threads made directly into the trigger casing, and the trigger blade is plastic.

As a starting point, there’s the T05 parts diagram and list from the diagram for a D240 T05 (available to download freely on the Diana site :  https://www.diana-airguns.de/en/service/spare-parts-lists  ). 

In picture #1 you see all the parts cleaned-up and laid down, ready to re-assemble. The pliers you see in the pic will be useful for parts and springs positionning, the small one is flat-bladed and is the ideal tool for small spring work.

To begin the re-assembly, first put the 2-legged spring (#53 in the diagram) into the hook (#52), in the correct position as seen in picture #2. Then use the needle-nose pliers to install the hook/spring assy. in the trigger casing. Once in place, I like to use a small screwdriver (a toothpic would do) to keep the spring in place for the pin installation. Just push the pin in place, and you're done for that part.

Second step is to install the lower lever (#102) and its spring (#50). In picture #5 you see it from underside, picture #6 from the rear. First install the lever, then the spring. Please note the small nub on the rear of the lever, this is where the spring goes. There's also a small recess/seat for the spring, built into the casing (not visible in the pic).

Picture #8 shows the installed spring.

Next is the trigger blade. I like to ''press'' it into place with my thumb, I find it's easier to insert the pin. Then the trigger return spring is installed.

[happymecanic]

Next step is to install the guiding and latch plates (#104 and #105). These plates have a rounded edge on the rim of the hole, the rounded edges both go toward the rear of the casing. The plate with a small tab is the latch plate and goes in the rear.

If you removed the spring stop plate, now's the time to put it in place (no part # in the diagram). Next you need to install the sliding part #106, that's called a ''lock'' in the list, and its spring (#108). It'll be easier to install the lock if you slightly depress the latch plate. Also at this stage, I like to install the main cross pins to help holding the parts aligned. Then the spring is installed.

Next is the safety lever (#107). You'll want the lock to be centered in the slot to ease the installation of the safety lever. To center it you can grab it from behind with needle-nose pliers and gently pull it back and center it. Be careful not to pull too strongly, and hold down the lock spring as it may want to launch (a strip of 3/4'' wide masking tape could be useful here).

Please note the gap between the lock and latch plate in picture #17, about 3 mm wide. This indicates the actual ''cocked'' condition of the trigger. To reset the trigger so that it can latch the piston rod, you just need to pull the trigger (you may want to do that with the plastic cover in place, but not absolutely necessary). With the trigger assy. out of the gun, you'll hear a clear ''CLIC'' sound and if you observe the lock/latch plate, there's no more gap (picture #18). If you don't reset your trigger after re-assembly, either out of the gun or in, you won't be able to cock the gun.

Next, if you're putting back together a Blackhawk, Airhawk etc, don't forget to install the stock screw nut in the front of the casing.

Last step is to gently remove the main cross pins and install the plastic cover, and you're done.

Happy thinkering,

Francois

[Ronno6]

Thanks for this post.

I put mine together several times before you taught me about the reset step..........
Works great now!

[Roadworthy]

Thank you for putting together this little "show and tell".  It should mike life simpler for many people.

[Artie]

Worthy effort for sure, thanks for posting.

[Toxylon]

Worthy indeed.

Thank you, Francois!

[Rocker1]

 Good stuff think I will pin this to the top of the page. David

[cjtamu]

Thank you sir, wonderful info. If I get brave enough to try tuning a T05 trigger it will come in handy.

[JackMan]

Excellent sharing of knowledge and documented as well.  Bravo