We can't help without a catalog number. Lionel was only in Mexico for very brief time, so the parts would most likely be of amount Clemens/Chesterfield manufacture.
Jon
Siding - go to this link at Lonel's website and download the appropriate product supplement. Note these are HUGE files. If you have the product number it will help you find the correct supplement. Otherwise you will have to guess and download and check content. Once you find your GP-7 in a supplement, there may or may not be the individual parts you need as Lionel compromised on the number of spare parts they stocked do to the cost of keeping/maintaining all that stuff. The coupler may only be shown as a truck assembly.
https://www.lionelsupport.com/service-documents/
You might also try contacting parts folks like East Coast Train parts or Olsens. Check ads in CTT.
Unfortunately George Tebolt has retired and is ceasing dealing with individuals as I understand it. I think you can only contact him via mail now.
Regards, Roy
Recntly Aquired a Lionel GP-7 loco made in Mexico Coupler broke of completely
Anyone khow part numbers for replacement parts?
The whole coupler that attaches to the truck by a swivel
Our community is FREE to join. To participate you must either login or register for an account.
Get the Classic Toy Trains newsletter delivered to your inbox twice a month