adjustable strut rod question
- Thread starter nrubino
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The adjustable strut rods allow you to set the length of the strut rod so that the lower control arm doesn't bind at all when traveling through its motion.
In theory, the stock strut rods should be the right length to allow this. But because of factory assembly tolerances, this isn't always the case in reality. In fact, in my experience its more often NOT the case, there was a TON of variance in these cars from the factory. Also, most of the reproduction strut rod bushings out there now are not the right thickness, which can cause problems with binding and getting the alignment on your car set properly. And of course, after 40+ years of wear and tear, the stock strut rods can be bent or otherwise damaged.
Adjusting them is usually covered in the instructions from the manufacturer, since there are a few different brands out there you want to make sure you follow the proper procedure for the ones you have. But basically, you just adjust the length of the strut rod until the lower control arm moves through the complete range of suspension travel without binding up. I usually adjust mine shorter until they just start to bind, then back them off until they're free again. The shorter the strut rod, the more positive caster you'll have, which is better for modern radial tires. Obviously, you don't want to have your control arms binding to get a little + caster, but there is a little bit of a range in which the LCA will move freely, and if you're on the "short" end of that range you'll have better caster numbers.
There also the matter of polyurethane LCA bushings, which don't locate the LCA's the same way as the original rubber ones do. In that case, the strut rod length is even more important in locating the LCA's, so adjustable strut rods really come in handy since its really unlikely the stock one will be the right length.
In theory, the stock strut rods should be the right length to allow this. But because of factory assembly tolerances, this isn't always the case in reality. In fact, in my experience its more often NOT the case, there was a TON of variance in these cars from the factory. Also, most of the reproduction strut rod bushings out there now are not the right thickness, which can cause problems with binding and getting the alignment on your car set properly. And of course, after 40+ years of wear and tear, the stock strut rods can be bent or otherwise damaged.
Adjusting them is usually covered in the instructions from the manufacturer, since there are a few different brands out there you want to make sure you follow the proper procedure for the ones you have. But basically, you just adjust the length of the strut rod until the lower control arm moves through the complete range of suspension travel without binding up. I usually adjust mine shorter until they just start to bind, then back them off until they're free again. The shorter the strut rod, the more positive caster you'll have, which is better for modern radial tires. Obviously, you don't want to have your control arms binding to get a little + caster, but there is a little bit of a range in which the LCA will move freely, and if you're on the "short" end of that range you'll have better caster numbers.
There also the matter of polyurethane LCA bushings, which don't locate the LCA's the same way as the original rubber ones do. In that case, the strut rod length is even more important in locating the LCA's, so adjustable strut rods really come in handy since its really unlikely the stock one will be the right length.
nerd racing
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Good write up! I've been looking for similar information. I might as well bite the bullet on a pair for my 64 since I'm going poly bushings.
Yes, if you're going to poly bushings I definitely think you should get some adjustable strut rods.
The "adjustable" name kind of gives a false impression of them. It's not that you need to adjust them all the time, you really just set them once. But the ability to make them the correct length is important, especially when you start changing things. But even if you're stock as a rock, the factory strut rods don't work perfectly for every car, they're just "close enough" for production. And keep in mind the factory alignment specs and bias ply tires are a far cry from radials and more modern alignment numbers.
If you really wanted to, you could build a set of non-adjustable strut rods and just size them to your car, since you're really only going to adjust them once (more than likely, unless you change suspension components again later). But it's probably a lot easier to just buy a set of adjustable strut rods.
nerd racing
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That makes sense. I plan on doing offset bushings and such and possibly dialing the car in for road course and autocross so adjustables are the ticket. Probably not for a while though.
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