Throwing some thoughts out there.
Since you had at several mechanics I assume the ball joints and inner control arm bushings are all in good shape?
Have you adjusted your wheel bearings correctly?
The fact that your right and left tie rods are that different is concerning. Do either of the steering arms look bent? - that's the bar on the back of the spindle that the tie rods connect to.
The geometry that makes a car drive centered is the caster. Try adding some more caster and see it that makes it better.
Steering Returnability | Henderson's Line-Up Brake & RV Inc.
Perhaps your frame is bent?
Here's a quote from elsewhere that I have heard before but am not knowledgeable about
"use the spreader bar and the tool to lock the steering box" I've heard that most shops including MB dealers don't do this. Hopefully someone else can comment more about this.
Thanks for the post Rumb.
On the ball joints and control arm bushings I don't think I can go from anything the first (regular shop/tire/mechanic place) said or did. Shop not even there now. Owner retired and sold up. The MB specialist it is at now trying to figure it out I have asked repeatedly if anything is loose up front. Been told everything is tight. I can say that the control arm bushings and ball joints have not been changed by me nor any recent owner by the look of them.
Been reading online about ball joint issues giving "memory steer" and things of that nature. At this point though, I'm grasping at straws and suspecting everything. Something wrong in the column (although I remember it spinning freely and the mechanic said it moved freely when the box was out), ball joints, control arm bushings, rear swing arm bushings (read where they can cause a hydroplane feel), a wreck that has something bent I don't know about or see anything obvious about from underneath, problems with the spindles etc. etc. ugh!
On the wheel bearings I redid the bearings with new bearings, seals and weighed out MB grease. I did not get the setting of the wheel bearing too much with the washer that should still spin so I had the MB shop the car is at make sure the wheel bearings were correctly set. They say all is okay. I asked about if there was any play in the wheel when you grab the top and bottom and was told all was tight and how it should be.
On the caster, the only thing that concerned me (at least on the sheet I have from the initial alignment) is that the right caster was showing just at the limit 3.4 with a 3.5 limit, where the left side was at 3.1 which is just one over the midpoint. Wondered if this could be contributing to some of the right bias drift/pull. Not sure about steering return though as my uneducated mind thought that being different like that would probably only cause the lack of return to be mostly one direction.
I'll ask at the shop to have them look at those steering arms. Good thought.
Not sure how I'd check on bent frame. More a body shop thing? I do know that the subframe recall had been done on the car a while ago. Looks like they welded some gusset type plates to the frame. Even wondered about a crack I can't see somewhere. Would have thought that the shop would have looked for that though as they are MB people who said they remember doing those recalls when they came out.
Doubting everything now though
I've just read the spreader bar and pin the box thing on another MB series. I'm probably going to talk to the shop this AM and see if I can talk to Chris and bring up some of this stuff.
Thanks again for the post!