Thats what happens when the drives are not perfectly even. Some thing has to give. So the the swivel bushings and pivots give.
Latham makes a slotted end for their inner tie bar. Merc used to make one for their steering system years ago.
Jim

Jim, help me overcome my ignorance. So if I want to add an external tie bar (IMCO, Latham, etc.) I should disconnect or modify the linkage that extends the steering arm to my port drive?
I understand the geometry of uneven tilt/trim. But I never considered how the internal steering would be effected...hmmm.

So a full hydraulic cleans this problem up, and also allows eliminating all that stock steering stuff?

Michael, The inside steering doesn't know how the two are connected. Either way it steers through the tiller arm and gimble ring on the stb side. You ultimately load one tiller or two. An outside add on system works well and is easy to install. It uses the inside stuff but actuates the outside cylinder instead of the one on the inner plate. Of course the full system is nice but how practical is it.
Jim

I went with a full hydraulic system. By far the biggest single improvement I've made.

Is the outer tie bar better than a inner? Would it be worth the change from inner to a outter?