I've got an old tgv set from the 80s or early 90s. All 4 gears on the drive axels are broke. I don't believe the geared axeles are available any more. What might my options be to get the train running again. Is there a newer engine I could buy and swap shells? Then just add the coupler some how.
You can't really do much besides buy a kato TGV set. Bachmann has not made any newer versions, and that version is long out of production. If you were to buy another Bachmann one it would probably suffer from gear issues too.
the wheel/gear/axles from the bachmann trolley will fit the tgv.