Well dang .... major Diana 56 failure

[oldwolf]

I have talked to Umarex, told them about the wobble, but they want me to send the action (no stock!) to them for analysis. I'm not going to do that. I guess I could go ahead and install the JM kit and see what happens.

Could this be a trigger problem? I hope not.

It will be interesting to see what you measure for wobble palonej.

[Motorhead]

A snug fitted spring guide tighter on NOT ONLY guide to spring I.D. but guide to cocking stem/rod will better center it as it is entering the trigger housing ( * where you will get the catch/snag feel when alignment errors exist )

FYI ...

A kit will also be better than factory set up IMO.

[palonej]

Hey Wolf.
Here is the piston I have.
There is no wobble on the stem.

[oldwolf]

Hmm, so know one really knows how much wobble is acceptable?

Too bad these pistons cannot be re-crimped somehow.

What do you guys recommend I do? Reuse the piston and install the new JM kit?

Palonj, where did you get that hmo piston and how much are they? Are they an improvement over the oem or where they made to only eliminate wobble?

I'm not looking for higher performance on my 52, just want to smooooth it out if at all possible.

Thanks.

[palonej]

A snug fitted spring guide tighter on NOT ONLY guide to spring I.D. but guide to cocking stem/rod will better center it as it is entering the trigger housing ( * where you will get the catch/snag feel when alignment errors exist )

FYI ...

A kit will also be better than factory set up IMO.

This is what you are looking for Wolf!!
Scott installed a Vortek kit in mine and it was a dream to shoot,,,,,,till the piston went. It was then put back to stock. Very BUZZZZY and jumpy. Not as much fun to shoot.

I bought the piston off the Yellow because we were having trouble getting one from Umarex.
Not too sure would trust it as I have read some issues on the DWC.

[GarthThomas]

If you didn't mind upgrading to a T06 you could get the T06 conversion kit from Chambers gun spares in the UK it comes with a new piston as well as the trigger unit, probably around $130.00 delivered.

[palonej]

Which trigger do you have Wolf??
I have a T06 on mine

[chuckinohio]

  The problems that seem to arise from using the HMO pistons, stem from the fact that they are not just a drop in part.
  From what I understand reading up on them, they need to be carefully sized and fitted to the compression cylinder, and then they work quite well.

  Across several forums, the consensus seems to be that the Hector built HMO rifles, and especially the HMO International tuned rifles run really sweet, and the rifles where the HMO piston is used as a drop in plug and play part MAY suffer from piston slam or drag depending on the ID of the compression cylinder.

  Hector Medina is still regularly active on the Yellow Forum Field Target subforum, If you are so inclined, you could probably message him from there and inquire.

[Bullit]

You make a great point Chuck.  There's a difference between a tuner doing the job, and a person just trying to "drill/mop/drop" the part in place, with little understanding of the why and parameters for the job.

[oldwolf]

I have the T05 trigger and I want to keep this repair simple and cost low.

I could convert to a T06, or replace the T05 piston, or reassemble using my current piston and my new JM kit.

I still am not clear about the loose stem, I think I am hearing from you guys that loose stems are common but too much looseness can cause my hang-up problem.

If the T06 pistons also have loose stems I don't see a great advantage going that route. Do they have the looseness issue?

Basically, I just want to get it running again reliably again, I might want to sell it even.

[palonej]

Pretty sure the HMO piston was sold with the idea Hector Medina would be doing the tune and install of the piston. After a number of guys paid in full and waited over a year for their guns, pretty sure they were 54s, the guns were shipped without the tune and install. Ton of problems with the point my friend Chuck brings up. Not all compression tubes are identical. Ugly situation that turned into a debacle.

Wolf, if you are thinking of going the T06 route, you can have the piston on me. I have no use for it. Even then you would need a T06 trigger. Getting expensive.