kwhizz
08-28-2016, 03:17 AM
The Story continues..........Just to go back in time.......the 66 Impala has a complete RideTech suspension front and rear (Coil-overs)......since completion the car has had a Ackermann issue.......driving straight it was a slot car.......turning was a different story.......Pull into the garage and the tires would leave black marks on the driveway, and sharp turns were pretty nasty.........so.....not being a suspension guy and the car driving normal when not turning.....I just accepted it as some nuance with the Ridetech suspension with slightly wider rims.........Keep in mind this car was finished 5 years ago...We drove the car on two Power Tours without any issues.......Then the Chevelle came into the picture and the Impala sat in the garage for two years
After driving the Chevelle during that time (no steering issues) and then getting back into driving the Impala.......I was determined to find out what was going on here.....At Barrett-Jackson last January I happened to stop at the RideTech display and talked to the people there and explained my concerns about the Ackermann issues..........To make a long story short, if this issue was going to get resolved I was going to have to do it myself........So, In talking with Mark Webster, he informed me that GM changed the 65-66 "B" body steering geometry to a new configuration in 67.........Hummmm !!!!
What changed and why???.............After a lot of research and asking stupid questions on a lot of web sites.......I found out that GM knew there were issues with the 65-66 models with wider rims such as Police cars and in Sept of 66 there was a Service Bulletin to address these issues.......This Bulletin basically gave the part numbers of all the new 67 design parts and the position and templates for the mounting holes for the repositioning of the 67 design Idler Arm assy........The Biggest difference is the mounting location of the Idler Arm .......In the 65-66 model years, the Idler arm was mounted thru a hole inside the frame rail.........67 and up it was mounted inside the frame rail and forward of the thru frame position.....
https://static1.pt-content.com/images/pt/2016/08/8BB9A8C7BE504353A852F2A86B593FFA-1.jpg
https://static1.pt-content.com/images/pt/2016/08/0B92440082434E3B9B79A50EDF19E067-1.jpg
It's pretty obvious by this picture the differences............Here's a picture of the difference in the spindle steering arms....
https://static1.pt-content.com/images/pt/2016/08/C739154740C34E9E83C5178481BEEE76-1.jpg
Pictures of the supplied templates provided in the 1966 Service Bulletin.......
https://static1.pt-content.com/images/pt/2016/08/06C07C12BFE64D8B9DC47155AAF377C8-1.jpg
https://static1.pt-content.com/images/pt/2016/08/16C7E347F0DE40A4A8BD44F0EBC02852-1.jpg
So........What I did was make the required steering arm spacer with tapped holes......got it in position .....and welded it in......
https://static1.pt-content.com/images/pt/2016/08/60EC6F38006B46E09E464CD73EA3B130-1.jpg
After installing the new Pitman Arm , centerlink, and Idler Arm.......It was apparent that there was something wrong as the centerlink went up on an angle and back towards the rear of the car........Hummmm!!!!..........After thinking about it and looking at what could be the problem.....I noticed that the 67 Pitman arm was about a 1/2" lower than the 66.........The Template must have been made with the 66 arm...........I made the centerlink parallel to the frame and the front crossmember.........Drilled new holes for the Idler arm (which corresponded to the lower 67 arm...........Makes perfect sense now ) and bolted everything in........Installed new Tie Rod ends.........Now everything is new.......Adjusted the toe roughly and when I pulled out of the garage to go to the alignment shop..........I knew right away there was a major difference as there wasn't any tire squeeling or scrubbing...........after alignment.........It is now the complete package.....Ackermann issue solved.........drives and steer's perfectly...............
After driving the Chevelle during that time (no steering issues) and then getting back into driving the Impala.......I was determined to find out what was going on here.....At Barrett-Jackson last January I happened to stop at the RideTech display and talked to the people there and explained my concerns about the Ackermann issues..........To make a long story short, if this issue was going to get resolved I was going to have to do it myself........So, In talking with Mark Webster, he informed me that GM changed the 65-66 "B" body steering geometry to a new configuration in 67.........Hummmm !!!!
What changed and why???.............After a lot of research and asking stupid questions on a lot of web sites.......I found out that GM knew there were issues with the 65-66 models with wider rims such as Police cars and in Sept of 66 there was a Service Bulletin to address these issues.......This Bulletin basically gave the part numbers of all the new 67 design parts and the position and templates for the mounting holes for the repositioning of the 67 design Idler Arm assy........The Biggest difference is the mounting location of the Idler Arm .......In the 65-66 model years, the Idler arm was mounted thru a hole inside the frame rail.........67 and up it was mounted inside the frame rail and forward of the thru frame position.....
https://static1.pt-content.com/images/pt/2016/08/8BB9A8C7BE504353A852F2A86B593FFA-1.jpg
https://static1.pt-content.com/images/pt/2016/08/0B92440082434E3B9B79A50EDF19E067-1.jpg
It's pretty obvious by this picture the differences............Here's a picture of the difference in the spindle steering arms....
https://static1.pt-content.com/images/pt/2016/08/C739154740C34E9E83C5178481BEEE76-1.jpg
Pictures of the supplied templates provided in the 1966 Service Bulletin.......
https://static1.pt-content.com/images/pt/2016/08/06C07C12BFE64D8B9DC47155AAF377C8-1.jpg
https://static1.pt-content.com/images/pt/2016/08/16C7E347F0DE40A4A8BD44F0EBC02852-1.jpg
So........What I did was make the required steering arm spacer with tapped holes......got it in position .....and welded it in......
https://static1.pt-content.com/images/pt/2016/08/60EC6F38006B46E09E464CD73EA3B130-1.jpg
After installing the new Pitman Arm , centerlink, and Idler Arm.......It was apparent that there was something wrong as the centerlink went up on an angle and back towards the rear of the car........Hummmm!!!!..........After thinking about it and looking at what could be the problem.....I noticed that the 67 Pitman arm was about a 1/2" lower than the 66.........The Template must have been made with the 66 arm...........I made the centerlink parallel to the frame and the front crossmember.........Drilled new holes for the Idler arm (which corresponded to the lower 67 arm...........Makes perfect sense now ) and bolted everything in........Installed new Tie Rod ends.........Now everything is new.......Adjusted the toe roughly and when I pulled out of the garage to go to the alignment shop..........I knew right away there was a major difference as there wasn't any tire squeeling or scrubbing...........after alignment.........It is now the complete package.....Ackermann issue solved.........drives and steer's perfectly...............