I do most of my maintenance and a while back did the front end alignment (I think I posted here about that).  The car drove well but I was still making what seemed to be a lot of small steering corrections.  I also noticed that the car seemed to jolt to one side or the other when abruptly changing the throttle position.

I knew the front end stuff was good and it finally occurred to me that maybe the cause of the issue could be found in the pins that fix the rear axle housing to the springs.  So yesterday, I took the rear housing off of the springs and looked.  Sure enough, the pins were too short to fully engage the holes in the axle spring perches.

I ordered some of the "correct" pins from NPD and fitted one of them on one side.  It seemed like it sort of engaged the hole in the perch but wasn't really where I thought it should be.  So I added a spacer (lockwasher) between the pin and the spring to get the pin farther into the perch.



I did the other side the same way, then drove the car.  What a difference!  It tracks straight now without me having to make tons of little steering inputs.  

I'm ashamed that I didn't pick up on this sooner - I put new rear springs on it in 2013 and about the same time, noticed the "jerking" with the throttle changes - but didn't realize that the pins that came with those springs were too short.  Better late than never, I guess.