Strut rod length

[GoldSwinger71]

I wanted to double check something I feel I did wrong... does anyone know the factory measurement of the strut rod from the inside of the lower control arm to the inside of the K-member?

Thanks!

-Daniel

 

[junkyardhero]

shoulder to shoulder outside measurement (where the rod mounts into the LCA to where the washer sits)

early: 16 7/8" (id= fine/fine thread)
late: 16 5/8" (id= fine/coarse)

hope those are what you're looking for. if not, let me know, they're sitting on the bench and can take whatever else might be needed

 

[72bluNblu]

Either version of the A-body strut rods can be used on any A-body K-frame 67-76 (at least). The only caveat is that you have to use the correct strut rod bushings for the strut rod, not the K frame.

So, if you have the early style strut rods 67-72, fine/fine thread, you need 67-72 strut rod bushings. If you use the later 73-76 strut rods, you need 73+ strut rod bushings.

The effective length of the strut rod wasn't changed, but because the bushing thickness was changed the shoulder on the strut rod was moved.

 

[GoldSwinger71]

Thanks for the info everyone, I ordered a new pair of rear tires and I'll have the shop do another alignment and tire balance. I plan to set the strut rod length to the factory size before I have them start work.

 

[GoldSwinger71]

Just for clarification, I put in the QA1 adjustable strut rods... and never took the initial measurements. Stupid, I know, but you learn! So I'll be resetting them to factory spec.

 

[72bluNblu]

Just for clarification, I put in the QA1 adjustable strut rods... and never took the initial measurements. Stupid, I know, but you learn! So I'll be resetting them to factory spec.

What kind of LCA bushings do you have?

The advantage to adjustable strut rods is that you set their length so there’s no binding in the motion of the LCA. And the length where there’s no binding in the suspension travel might not be the factory length.

You should start so that the LCA is neutral, not being pushed/pulled by the strut rod, and then cycle the suspension up and down from bump stop to bump stop. Typically I’ve found that having the strut rods with slight tension on them (slight pull on the LCA) results in the least amount of binding in the LCA travel. But it will depend on your components and even the factory tolerances on your K frame, suspension mounting points, etc. The big, soft rubber bushings in the factory stuff is all there because of the loose factory tolerances, if you remove those strut rod lengths have to be more accurate.

 

[GoldSwinger71]

What kind of LCA bushings do you have?

The advantage to adjustable strut rods is that you set their length so there’s no binding in the motion of the LCA. And the length where there’s no binding in the suspension travel might not be the factory length.

You should start so that the LCA is neutral, not being pushed/pulled by the strut rod, and then cycle the suspension up and down from bump stop to bump stop. Typically I’ve found that having the strut rods with slight tension on them (slight pull on the LCA) results in the least amount of binding in the LCA travel. But it will depend on your components and even the factory tolerances on your K frame, suspension mounting points, etc. The big, soft rubber bushings in the factory stuff is all there because of the loose factory tolerances, if you remove those strut rod lengths have to be more accurate.

Qa1 adjustable strut rods. They basically say “measure the factory rods and set the length.”

 

[72bluNblu]

Qa1 adjustable strut rods. They basically say “measure the factory rods and set the length.”

That’s a starting point only. With the factory strut rods the large rubber bushing compresses and can keep the strut rod from pushing the LCA out of position if there’s factory tolerance issues. With the solid blocks on the adjustable struts that can’t happen, so the strut can push or pull the LCA out of a neutral position.

The factory used big, soft rubber bushings to make up for loose suspension tolerances. If you take out the slop, the length has to be more accurate or it will bind up. Set it to the factory length to start, but if you don’t check for binding and make adjustments you’re not setting yourself up for success. The adjustable struts require tuning.

 

[AJ/FormS]

I'm gunna stir the pot here by saying that;
when the problem-solver UCA bushings did not give me enough (IMO) Caster, I went looking elsewhere and Strutrod length was easy-peasy. I just pulled them into the K. Then went to work fixing the bumpsteer.
After a while, I got the Caster up to ~7* and change, at zero-camber.
After I set the camber to 1/5 neg, I had IIRC, around 4 Caster left.

I'm a streeter, so I thought that should be enough.
I liked it. That was done in the very early 2000s.
I didn't stop there; I dropped the steering box, rebuilt it, and added reaction springs several times to get just the right feel.

 

[72bluNblu]

I'm gunna stir the pot here by saying that;
when the problem-solver UCA bushings did not give me enough (IMO) Caster, I went looking elsewhere and Strutrod length was easy-peasy. I just pulled them into the K. Then went to work fixing the bumpsteer.
After a while, I got the Caster up to ~7* and change, at zero-camber.
After I set the camber to 1/5 neg, I had IIRC, around 4 Caster left.

I'm a streeter, so I thought that should be enough.
I liked it. That was done in the very early 2000s.
I didn't stop there; I dropped the steering box, rebuilt it, and added reaction springs several times to get just the right feel.

Yeah, I wouldn't adjust the strut rod length to get additional caster at the expense of adding binding.

Now, that being said, my adjustable strut rods are shorter than factory strut rods, so, they are adding caster. The change in length may also be the result of some of my aftermarket parts (delrin LCA bushings, QA1 LCA's, etc). But the important part is that the LCA can move through its range of travel without any binding from the strut rod. That should be the priority, you shouldn't use the strut rods to get additional caster if adding that also causes binding.

But yeah, properly adjusting the length of the strut rods can definitely result in some additional caster in some instances at least.