Herb, there's a decent set of videos on youtube for a fellow named Jonathan W who resurrected a Unit crane, which has a lot of common features with your one - Detroit, all mechanical. If you take a swing through the videos, it might provide some additional intel on yours. For instance, in his crane, he couldn't engage the dog to drive the crane, and a clutch mechanism required freeing up to gain all the travel it needed to be adjusted properly. It's not specifically what you're looking for but it might help hopefully.

And this link to an excavator owned by a Tim Hoover who displays it at the HCEA show in Simcoe Ontario each year. He may have some literature and even though it's a digger, it could well have a similar undercarriage. The video says that he had to fully rebuild his undercarriage and drives so he would know a lot about them and might be able to help you trouble-shoot.