After disassembling the shift linkage on the 1985 300TD in order to replace a shot front bushing, I have reassembled the linkage with the new bushing in place.

For all who attempt this somewhat difficult but simple repair:

PULL THE TRANSMISSION SHIFT LEVER OFF OF IT'S PIN FIRST!

Then disconnect the selector rod from the lower selector lever (at the rear bushing).
Then pull the rod out towards the rear with the lever still attached.

The bushing installation is simple and straightforward from there. The force required to seat the bushing makes it virtually impossible to accomplish this with the shift lever tucked up in the tunell next to the tranny housing.
Very easy with the lever on the workbench.

Reassemble in reverse order.