I'm happy to report that my steering issues seem to be resolved. Although no "smoking gun" was found, a thorough inspection of the frame, drive train and suspension found a few loose bolts. After tightening everything up the 3 wheeler seems to be back to it's usual self.
It doesn't make much sense to me, but here's what I found.
1) On both the left and right side, I found loose bolts on the lower frame end of the diagonal support the steering rack is mounted to. I was able to apply a solid 1/2 - 3/4 turn.
2) On the right side tie-rod ball joint, I was able to get a bit over 1/4 turn.
3) At the rear of the transmission there are two roughly 5-6" bolts that mount the transmission to a long stainless steel member. On one of these bolts I got a healthy 4-5 full turns. (I doubt this contributed to my symptoms.
Thank you all for the support and feedback.
