Originally Posted by Bandera

By "lubed" did you disassemble the shift levers from their mounts, clean all of the bits 'n bobs lube lightly and re-assemble?
Although DT controls have the shortest length of shift cable in the most unencumbered by casing design a fresh well lubed set of new cables w/ new casing and clean guides would be advised.
What make/model of DT controls are you working with? Odds are extremely good the C&V crowd has experience with their quirks. Attach a pic as in Post #23 for clarity.

-Bandera