Large Scale Central

Climax gear box

Does anyone have experience with the Climax center gearbox failure?
Mine is lurching and ticking, if I grab the piston rod and stop it’s movement the loco still lurches along.

Bachmann has/had replacement gear boxes but guess what the are out if stock.
Any ideas?

Does any of the Bachmann Climax Performance section of George Schreyer’s tips help?