Leandro, since you say returning the loco to Lionel is not an option, if you are mechanically inclined, I would carefully remove both trucks and motors and on the largest table you can find I would take both trucks completely apart as far as things are held together with screws clips and solder. You should not have to deal with parts such as wheels and axles which are pressed together. I would keep the parts for the front and rear trucks carefully separated so as to insure no parts got mixed up and I would line them up in neat rows and one by one compare each part of each truck. Assuming that one truck is functioning well as designed I would take each part of that truck, one by one, and compare it to the corresponding part of the truck which is binding up. As you disassemble the loco make many photos or videos of the process. You can even narrate the video describing what you are about to do. if possible, before starting the process I would find the Lionel parts diagrams for your loco and print them out, if they are available. If you are not accustomed to working on or around the electronics on modern locos you will need to wear a grounding bracelet to guard against static discharge when you are handling the boards on the loco and a proper grounded static safe soldering iron. NOT A SOLDERING GUN. Post us some photos and videos and I am sure you will have plenty of help from forum members. Good Luck! j
JohnActon, Thanks !
I will wait to back the page Lionel support for I can take " Lionel parts diagrams".
I also need to wait my new FOAM CRADLE ( My dog ate and destroyed).
Carl, Thanks !
Ted S, I will disassemble all and I'll take a new pictures ! I'll try after to buy a new truck !
Shawn, Yes ..strange issues...
Thanks, Guys ! I Love this Forum ! Coming soon new reports !