Strut Rod Help Please

[Phreakish]

I need some schoolin on strut rods for A bodies. I know there are a couple of different styles. Are they interchangeable? Is one style "better" than the other? I am trying to decide between adjustable strut rods and factory strut rods and wondered about the differences? Thank you drive through.

QA1 rods are harder to install without removing the lower control arm. PST ones are easier to install with the arm still installed. The QA1 are easier to adjust once installed. The PST require the rod end to be loosened, or having to loosen the lower strut rod hardware at the arm to spin the rod to make the adjustment. It's not a big deal, but more steps, and it's not like ongoing adjustment is ever needed anyway. I was already removing the control arm, and so I used the QA1 rods and love them. Quality, tight, and went in fine. The hotchkiss look very similar to the QA1 design. Firm Feel offers a set which use stock-style front bushings, but have more adjustment. I trust Firm Feel, and they're the cheapest ($225) of the rest, but I wanted freer movement to go along with my eventual goals for the car - YMMV.

To me, the adjustable rods are an 'easy' (but expensive) fix for the lack of QUALITY and available stock-style bushings for the stock strut rods. Since I don't have a pile of OEM parts salvaged or NOS from back in the day, it just made good sense to use these and not have to deal with crappy aftermarket stuff that either won't last or won't fit because some bean counter consolidated part numbers across too many applications.

I'm sure the rods could be used to pull in more caster, but it doesn't take a rocket surgeon to figure out it would rip up stock style bushings if used on the street that way for any real mileage. I'm sure it would also destroy any other bushing style too by binding the pivot like that. Might be OK for a 1/4 mile at a time or glass smooth roads though!

I've not put on a ton of mileage since I installed them, and I installed viking double adjustable shocks at the same time along with poly bushings. But I have zero complaints with how the front rides!

 

[RustyRatRod]

QA1 rods are harder to install without removing the lower control arm. PST ones are easier to install with the arm still installed. The QA1 are easier to adjust once installed. The PST require the rod end to be loosened, or having to loosen the lower strut rod hardware at the arm to spin the rod to make the adjustment. It's not a big deal, but more steps, and it's not like ongoing adjustment is ever needed anyway. I was already removing the control arm, and so I used the QA1 rods and love them. Quality, tight, and went in fine. The hotchkiss look very similar to the QA1 design. Firm Feel offers a set which use stock-style front bushings, but have more adjustment. I trust Firm Feel, and they're the cheapest ($225) of the rest, but I wanted freer movement to go along with my eventual goals for the car - YMMV.

To me, the adjustable rods are an 'easy' (but expensive) fix for the lack of QUALITY and available stock-style bushings for the stock strut rods. Since I don't have a pile of OEM parts salvaged or NOS from back in the day, it just made good sense to use these and not have to deal with crappy aftermarket stuff that either won't last or won't fit because some bean counter consolidated part numbers across too many applications.

I'm sure the rods could be used to pull in more caster, but it doesn't take a rocket surgeon to figure out it would rip up stock style bushings if used on the street that way for any real mileage. I'm sure it would also destroy any other bushing style too by binding the pivot like that. Might be OK for a 1/4 mile at a time or glass smooth roads though!

I've not put on a ton of mileage since I installed them, and I installed viking double adjustable shocks at the same time along with poly bushings. But I have zero complaints with how the front rides!

Thanks for this! When I do the job, I'm also going to be installing LCA bushings at the same time, so the control arms will be out.

 

[MopaR&D]

Yeah, sorry about that, blu is usually spot on, and near 2 decades, I read and agreed with mosta what he said, seldom offering a different/option, when I did, we danced .
I think my opinion was just that, of the cheap easy way to achieve what you sought, without being jumped on and lectured, ffs, on stuff I am intimately, familiar .
It was my opinion Rusty I offered it .
I said jmo before and after, and woulda left it, if not for his first sentence ffs.
Done,
Good luck .
Again, my apology .

Kinda don't blame you tbh, it would seem that way since he quoted you first but that's the downside of this format. If we were all standing around chatting in person it would probably be a different story.

I've had poly LCA bushings and PST adjustable strut rods on my Duster for years, at least 10k miles (don't get to drive it as much as I'd like lately). With the torsion bar out of its socket I could easily move the LCA through its travel with adj strut rods when adjusted correctly. Car is more stable under braking, especially while turning at the same time.

 

[RustyRatRod]

Kinda don't blame you tbh, it would seem that way since he quoted you first but that's the downside of this format. If we were all standing around chatting in person it would probably be a different story.

I've had poly LCA bushings and PST adjustable strut rods on my Duster for years, at least 10k miles (don't get to drive it as much as I'd like lately). With the torsion bar out of its socket I could easily move the LCA through its travel with adj strut rods when adjusted correctly. Car is more stable under braking, especially while turning at the same time.

Thank you! That's the kinda feedback I am lookin for!

I agree about all us sittin around in person, but I digress, I'm a hot head and would probably smack a couple of these guys. LOL

 

[1973dust]

I just thought of a detail about the QA1's that I don't think I've seen mentioned by anyone else. The factory rods have a .625 dia. turn that fits into the LCA . The QA1's are threaded 9/16-18 all the way from the end to the LCA shoulder. I was disappointed in that, considering how much money you pay for them. Probably overkill and not a big deal, but on mine, I made a .625 od bushing with 9/16-18 id threads for both rods. I didn't like the idea of the threaded strut rod end being able to move around in the LCA.

 

[72bluNblu]

I couldn't read all that crap.
Back in the 60's we used, modified, fabricated everything, experimented, learned.
All my suspension is loosy, Goosy, to the point of flop .
You do know I built racecars ?
Tested geometries, roll center, long before the interweb.
Theory all you want, we did what was nec, with what knowledge/resources were available, and got results, more knowledge, better results.
Championship last 2 yrs, track records as well.
How long since you actually built a car ?
Keep it brief, not another tome .
Got some pretty nice hardware to prove it .
Preach on, - thump your chest - others will listen, you say good stuff.
I consider you one of the "Oracles" here, - don't go stupid on me now !

So, you didn’t read the explanation, but you’ve gotta come after me personally?

Fine. Strut rods are not for adjusting caster. See? Simple. They’re there to prevent excessive caster change, and adjustable strut rods do that better.

I built my Challenger’s suspension in 2008 with adjustable strut rods and ran it for 70k street miles, the strut rods and their heims are in great shape.

I built my Duster’s suspension up the first time in 2012, and that set of adjustable strut rods has done close to 40k street miles now. It’s seen a bunch of upgrades since but the same strut rods are on it.

What worked for a few hundred miles on a race car 50 years ago isn’t always relevant for a street car today.

I just thought of a detail about the QA1's that I don't think I've seen mentioned by anyone else. The factory rods have a .625 dia. turn that fits into the LCA . The QA1's are threaded 9/16-18 all the way from the end to the LCA shoulder. I was disappointed in that, considering how much money you pay for them. Probably overkill and not a big deal, but on mine, I made a .625 od bushing with 9/16-18 id threads for both rods. I didn't like the idea of the threaded strut rod end being able to move around in the LCA.

Again, I put 70k+ miles on my QA1 style adjustable strut rods. If you torque the nuts to 75 ft/lbs as instructed they won’t move. The other style that uses a bolt through the LCA attachment is also just 9/16 threaded hardware. I’ve had both styles and had them on and off the cars, I have never seen damage to the threads or the LCA mount that would indicate movement between the hardware and the LCA. Putting a shouldered bushing on there certainly won’t hurt anything, but based on my experience it is not necessary either.

 

[MopaR&D]

Again, I put 70k+ miles on my QA1 style adjustable strut rods. If you torque the nuts to 75 ft/lbs as instructed they won’t move. The other style that uses a bolt through the LCA attachment is also just 9/16 threaded hardware. I’ve had both styles and had them on and off the cars, I have never seen damage to the threads or the LCA mount that would indicate movement between the hardware and the LCA. Putting a shouldered bushing on there certainly won’t hurt anything, but based on my experience it is not necessary either.

Got me curious so I looked it up, proof load (max tensile load before permanently deforming) for a typical Grade 8, 9/16" bolt is 21,800 lbs. Grade 5 is 15,000 lbs, Grade 2 is 10,000. I'm sure the loads can get pretty high under hard braking with big brakes and wide grippy tires but I feel like if you're putting over 10k lbs tensile force on the strut rod there is other stuff that will break first. I don't know what the typical tensile load would be on that part though off the top of my head tbh.

 

[72bluNblu]

Got me curious so I looked it up, proof load (max tensile load before permanently deforming) for a typical Grade 8, 9/16" bolt is 21,800 lbs. Grade 5 is 15,000 lbs, Grade 2 is 10,000. I'm sure the loads can get pretty high under hard braking with big brakes and wide grippy tires but I feel like if you're putting over 10k lbs tensile force on the strut rod there is other stuff that will break first. I don't know what the typical tensile load would be on that part though off the top of my head tbh.

Yeah so with any kind of street or even commercially available race tires you’re not going to be able to pull much more than 1G of force on braking or cornering. And then on the front you’re taking that load at the tire and distributing it through the UCA, LCA and strut rod. So, no where near the limits for the hardware.