Hi, I don't know where to send this message but I had 3 Dragon Sd.kfz 7s, code: 6542, 6553 and 6562. Today morning, I checked the models and found that ther two sets of wheels smelt and leaked like that, they were still locked in the bags.
I cut out one set I place over 2 hours at room tempature (around 29-32 degree Celcius), It dried and deform like the right most.
I found that when the wheel dried out, it deform and hardened like normal plastic but easily broken.

it's the bags, not the styrene.
the bags cotai chemicals to keep them soft, they leech out and impact the plastic.

This has been exhaustively discussed on this forum already.

https://armorama.kitmaker.net/forums/227962&page=1

There's something up with the mix in certain batches of the DS where the mix destabilizes, oil oozes out and it dries out and becomes brittle. This has long been a problem with various vinyl compounds used in model kits going back decades.

Fortunately yours was separately bagged as when exposed to the plastic of the kit the plastic could melt.

Thank you, I've already know about DS tracks, and have bought trumpeter workable tracks for my Dragon M1A2 SEP, M1A2 AIM. But I can't imagined this. Better run for resin wheel sets.
P/S: Dragon don't provide a replacement, do they?

Good luck with DRAGON as far as any correspondence with them is concerned. Many queries sent to DRAGON by their customers have largely been ignored...

RESIN replacements for your tires are your best bet- Try DEF...

Sometimes; may depend on the specific kit and whether they still have a stock to draw from. They discontinued a bunch of kits last year.

Does it make a difference if you take them out of the plastic wrap? Can they be coated with something to stabilize them? I've got some old Revell fire truck tires (Unimogs and the big airport model) that destabilized and turned all hard and nasty.

THIS is exactly why I buy RESIN Wheel/Tire replacements for any of my wheeled 1/35 model vehicles at the same time I buy the kit in question. I don't have much hair left, so I'm not going to tear any hair that I still have out in frustration when the time comes to build said kit...

It's not the bag that does it but an instability in the material. Taking it out of the bag risks the item interacting with other parts. Decomposing DS has been known to melt styrene. Priming or painting will not stop a chemical instability in the compound. It's not a reaction to the environment, but batches of the material itself.

I had tires in an ancient Italeri Opel Blitz melt into the cargo bed. I also had Airfix tracks from kits in the early 1970s melt into the plastic. Nitto, Fujimi track got hard and shattered, Midori wheels and track of the same period dried out and fell to pieces despite being primed and painted.

So this is an old problem. Airfix and Italeri changed the vinyl they used way back when and it's only vintage kits that you have to worry about.

Supposedly, Dragon is aware of the problem and there's supposed to be better control of the compound. But it has proven difficult to impossible to get replacement bits from them.

And all this was gone over exhaustively in several previous threads. There's nothing new to add. Use the search function and look for Dragon DS and you'll find a half dozen pages of posts about it.

I have that Italeri Blitz on my SOD. The tires left an impression in the cargo bed.