Adjustable Strut Rods
Thank you for all your replies, though I do not understand everything stated so please bear with my questions. First, when replacing the bushings, it seems better to replace them with the hard rubber bushings rather than the poly ones due to the allowance of movement in multiple planes as opposed to the poly bushings. Polys may last longer but the original rubber most likely will perform better.....
Second, the adjustable strut rods are more to prevent binding on the lower control arms throughout its motion during use. How does one even know whether the suspension is binding or not? What does that mean to cycle the suspension through its complete range of travel and adjust so that there's no binding? Where is the binding checked at? Third, to be sure I'm understanding right, this strut rod adjustment is not used at all for Caster specification adjustments? Only for assurance of release/dissipation of binding? Would a front end alignment tech know what to look for in regards to set it so there's no binding??
If I was going to use bushings at the strut rod I would use the rubber ones, yes. The poly ones aren't always the right width, and they would tend to cause more binding rather than less.
To check for binding, what I do is put the car up on jackstands and remove the wheels. Then I remove the torsion bar adjusters and the plate that holds the adjuster in the LCA. Then remove the shock. With all of that done, you should be able to lift and drop the control arms and spindle, moving the suspension through its entire range of travel between the bump stops. All you should be working against is the weight of the suspension parts when you lift them. What you typically find when you do this is that the suspension does not move freely from bump stop to bump stop, there are generally areas of added resistance that occur at the extremes of travel right before you hit the bump stops. That's binding. If you remove the strut rod and check this again you should be able to move the suspension freely with very little added resistance anywhere.
Setting the adjustable strut rods so there's no binding follows the same procedure. If you measure the original strut rod from the back side of the K frame to the LCA, and then set the adjustable strut rod so it's the same length from the back of the K to the LCA you should be roughly in the ball park. Then with the adjustable strut rod installed you can look at the LCA and see if it's perpendicular to the frame rail. If it's not, adjust the strut rod so the LCA is perpendicular to the frame rail and check for binding. If the LCA is perpendicular to the frame rail there shouldn't be much or any binding. Then normally what I do from there is shorten the adjustable strut rod until is starts to bind, then back it off again until it moves freely. If you start to shorten it and find it immediately binds worse, you may need to lengthen it. The first time you do this it may take awhile to find the "sweet spot" where there's no binding.
With rubber LCA bushings there will always be more resistance as you get to the extremes of travel, because of how the rubber LCA bushings work. Nothing spins, so, the entire range of travel of the LCA is based on the rubber LCA bushing flexing. That's why you tighten the LCA pivot nuts at ride height with OE style rubber LCA bushings, because you want them to be neutral at ride height. That way compression is flexing the bushing in one direction and extension flexes it in the opposite direction, which minimizes the amount of flex in one direction. Over flex the rubber bushings and they tear.
With poly or Delrin LCA bushings the bushing spins on the LCA pivot pin, so there's no real resistance for moving the LCA up and down. It also makes it easier to set the length on the adjustable strut rods, you shorten them until the LCA is pulled against the poly or Delrin bushing, then check for binding, and usually shorten the strut rod another turn or two. With the adjustable strut rods and poly or Delrin bushings at the LCA there's very little resistance in moving the spindle and control arms up and down.
And no, I would not expect any alignment tech that I've met lately to have any idea how to do this. You'd need a race shop that also does alignments. The alignment techs at wheel and tire shops are generally at the limits of their capability just turning caster/camber bolts or adding shims to put the suspension "in the green" on the computer screen. Most of them know very little about actual suspension design or function, and aftermarket adjustable parts are not something they typically deal with. Many of them won't even do the alignment if you have aftermarket parts installed that they didn't install at that shop, and usually they will only set the alignment to the factory specs, which on these cars was for bias ply tires and is completely wrong for radials. Which is why I bought my own alignment tools and do my alignments myself.
