Update to my steering issues:
So, after reviewing my alignment report making all other steering and giving some thought, I decided to focus on the thrust angle and rear toe. I made a number of frame measurements and everything was square EXCEPT…. I know that I wrote that my rear axle was “dead nuts square” which was true in that it was square within its mounting location. But, I found that the LH front spring hanger perch bracket was 1/4” closer to the front of the car than the RH side which placed the rear left wheel ahead of the right wheel causing the .29* thrust angle that caused the car to “crabwalk” or “dog track”and the steering wheel to be off center to the right.
So, now I start to look for correction by shimming the left side front spring hanger. Saw that they were (supposedly) available from Hotchkis #3003 through many vendors and after reading the ONLY example I could find of an actual installation here:
Gallery: Thrust Angle Adjustment with Mancini Racing and Hotchkis Sport Suspension - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech
After reading the article, I chose to buy some from Summit Racing. A pack of (6) 1/32 shims #3003 cost me over $70 with tax and shipping. Picture #1 below is a picture of the shim (supposedly for a 70-74 E body)) from the installation instructions. Picture #2 is the actual shim that comes in the kit and according to HOTCHKIS, the only one they produce. Picture #3 shows how the shim would fit (or NOT fit) if you were to attempt to “slide” them in from the bottom AS IS NECESSARY unless you remove the spring mounts from the car! Picture #4 shows that they might actually fit if installed upside down; as in REMOVING THE SPRINGS. Bottom line…. They don’t work and will NEVER work on a 70-74 E-body with stock spring mounts and the corresponding factory spring mount hole location in the perch bracket. When I talked to the tech/sales rep at HOTCHKIS he said: “Yes, I see how they won’t work. They must be for our spring mounts.” Uh, I don’t think so unless you want to drill new holes in the perch plates. So, I don’t understand how they worked on that 69 Dart in the article above. Are 69 Dart spring hangers different than the ones an E-body? Moving on…. Picture #5 is of ones I bought from BERGMAN AUTO CRAFT here in (Hempstead) NC. I bought (4) 1/8” shims (the only size he has) for about $39. Yes, they look like the ones in picture #1 below. These actually work PERFECTLY.
It is ALARMING to me that SUMMIT and ALL of the other vendors would sell these as fitting E-body cars without actually verifying the fit!
Now… I decided to install 3/8” of shims based on some rough calculations (even though my rear ended measured 1/4” forward) AND what it took (1/8”) for those guys to correct .08 on that 69 Dart.
They were very easy to install. I just barely took the weight off the axle with a bottle jack under the rear subframe section with the wheel on the ground which relieved the preload from the springs; loosened the bolts, lightly pryed the mount back and lightly tapped in the shims. Took all of 15 minutes!
Returned to alignment shop. Picture #6 is of the original attempt at alignment. Picture # 7 is the second alignment. As you can see, the 3/8” shims moved the thrust angle from .29 to -.17. So, we pulled out one 1/8” shim for a final thrust angle of -.08 with 1/4” of shim.
THE BOTTOM LINE:
Now the car drives nice and straight, no pull, steering wheel nicely centered, and returns to center fairly good even though we could achieve only about 1 1/2* of positive caster and still have some negative camber. Front and rear toe is nearly optimal.
PLEASE Do NOT buy the #3003 shim kit if you need to correct the thrust angle on your stock E-body car. Use the ones from Peter Bergman at BAC.
I apologize for this lengthy post but just wanted to get the whole story out there.
Kevin
Good you got it sorted out. Good info from you experience.
