I did this on mine about 2 years ago. It made a huge improvement to DW . I did notice the truck "tracked" differently going down the road after 2 washer install on both sides. Not bad... just different. I just rebuilt the whole front end this weekend. What I noticed was the new springs felt a ton stiffer than the old. The before comparison was with the front axle on jackstands, I could place my foot on the rim and cause the rim to deflect(compress the spring) without full body weight. with new pins bushings and springs it takes all my body weight to get even the slightest deflection. I'd say washers are a good temp fix, but looking back If I was going to pop the cap off, I'd rather throw at least new bushings and springs in. Also, I was amazed to see how much the original bushings had worn. It may be possible for that bushing to wear to the point where the washer the spring sits on the contact the top of the king pin. If that happens, no amount of fender washers will help.