as Todd already mentioned - there is nothing to worry about by disassembling.
As TRIX as a German manufacturer under the parentship of Märklin, all products (however stupid this may be...) have to have the Euro-style "short-coupling-kinematics", seen here:
European rolling stock has buffers - but on models they usually are non-functional (not sprung), so in order to run "buffer on buffer" you need such a device for curves. There was a very large (and ugly) lever connected to that spring on your car, similar to this one:
In curves that lever not only moves from side to side, but also increasingly away from the car end - seen in the first link. The spring just tows it back to normal position on straight track.
It doesn't work bad and enables you to run even the longest passenger cars short-coupled on curves down to 15" - but such long cars nonetheless look stupid on such curves, and I definitely would make the buffers working first (of course there are many different ones available) before using such odd devices...
This system and the refusal of several leading European manufacturers to develop anything better and more prototypical was one reason for me to quit Euro modeling with VERY few exceptions - or at least the US system with Kadee boxes and knuckle couplers were a VERY welcomed cherry on the cake in my beginning of US modeling...
Just screw on a Kadee box where it belongs, and everything should be fine.
Modeling the early post-war years up to about 1953
Gesendet: Samstag, 16. Januar 2021 um 21:45 Uhr
Von: "Jeffrey White" <jrwhite@...>
Betreff: [RealSTMFC] What are the springs in the Trix 40 foot boxcar frame for
I just received a Trix IC 40 ft double door boxcar. I turned it over to look at the coupler boxes and discovered there are srpings in the underframe.
I've never seen this before. They don't seem to have a function but I haven't disassembled the car. Thought I'd ask if there is anything I should know before taking it apart to change out the trucks and couplers.