Adjustable strut rods

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kg340

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Has anyone used the adjustable strut rods from Firm Feel?? I recently read in 1 of the mopar tech articles that strut rods with heim joints should be avoided. I know a lot of guys are using the heim joint bars, but has anyone tried the Firm Feel ones??
 
Grease the joints and wrap them with covers then they last ok. (they do make covers)
I personally wouldn't put them on a daily driver though.

I'm sure opinions vary on that.
 
What tech article? I’d be interested in seeing what they think the issues with heims at the strut rods are. I ran Heim jointed adjustable strut rods on my Challenger for over 60k miles, using the car as a year round daily driver. No boots or seals on the heims either. No issues at all, the heims aren’t even worn out after all that. Same on my Duster, although I’m only a bit over 12k miles on it so far. If I can’t wear them out driving in the rain, snow, on gravel, etc, I don’t see it being a problem.

I don’t see any big issues with the Firm Feel adjustable strut rods though. They allow for the strut rod length to be adjusted, which is good for any LCA bushing and needed for poly or delrin LCA bushings. They just use a bushing like the OE strut rods. So they’d allow a bit more fore/aft movement than the heims even if you used poly bushings. And there would be a higher chance of binding, and more resistance from the strut rod motion acting on the LCA. But for a street car it would still be an improvement over stock.
 
I believe the article was in Mopar Action.

Got a month or year? I’ll take a look for it. Is it an Ehrenberg article? Cause that would make sense.
 
Got a month or year? I’ll take a look for it. Is it an Ehrenberg article? Cause that would make sense.
Yes it was Ehrenberg, it was in the latest issue. He states removes compliance from suspension, shock values go to infinity?? Moves the pivot point 1.5- 2"?? Heim joint do not last on the street,even with covers. I was going to try the Firm Feel ones,as they do not have joints, but are adjustable in length. On the other hand I found the QA1 rods For $213.00 online ,they look like excellent pieces.
 
I have a set that I used for years on my Dart then when it was taken apart I moved them onto my Valiant. no issues, no wear.
I do occasionally wipe them down and lightly oil them once a year. I got mine from RMS not that I think anyone's are all that much different
 
Yes it was Ehrenberg, it was in the latest issue. He states removes compliance from suspension, shock values go to infinity?? Moves the pivot point 1.5- 2"?? Heim joint do not last on the street,even with covers. I was going to try the Firm Feel ones,as they do not have joints, but are adjustable in length. On the other hand I found the QA1 rods For $213.00 online ,they look like excellent pieces.

Yeah it figures. He says those things, but does he provide suspension geometry numbers? Does he actually show that moving the pivot point causes some kind of issue? Because I've used adjustable strut rods with heims on all of my cars, and have yet to get into an issue with setting them up. I get no binding at all through the entire range of motion I have with my LCA's, which is better than what you can do with the stock bushing strut rods. Now, my cars are lowered and run large torsion bars, so, the LCA travel range is different than stock. But they're adjustable strut rods for a reason. Shock values to infinity? That doesn't even make sense. The strut rods are along for the ride with up/down travel. They locate the LCA fore/aft, and there's no shock absorber in that direction. Nor is it the primary direction of motion. Sure, the stock bushings probably absorb some road noise, but they also allow the LCA to move around, which isn't what you want.

He did the same thing in his "disk-o-tech" article with the FMJ spindles. "Oh, they're taller, they mess everything up, the geometry is terrible, they'll over-angle the ball joints, blah, blah blah". Mopar Muscle did an article later that tracked the bump steer and suspension geometry numbers for the FMH spindles vs the 73-76 A-body spindles and found that pretty much everything Ehrenberg said was BS. Yes, there were some small changes in geometry, but in certain applications the changes were actually an improvement. So, Ehrenberg pulled all the BS about the FMJ spindles completely out of his *** and didn't ever actually do any testing to show why/how it could be a problem.

The QA1 strut rods are pretty much exactly what I ran on my Challenger. Mine were made by CAP before Qa1 bought them out, but they're the same parts, aluminum construction for the blocks and tubes. When my Challenger gets back on the road they'll be on it, don't even need to change out the heims. They did somewhere over 60k miles, without covers/boots, with year round, daily driver use. Like vitamindart said I would occasionally wipe them down and hit them with some dry graphite lube, but that's it. And now they make boots that will work for that application, so, you could hit them with dry lube and put covers on them and probably never have to worry about them again. Most people would probably never put 60k+ all weather miles on their Mopar anyway.

I do agree somewhat on using heims on street cars, there are some applications where they should not be used. I ran Hotchkis UCA's on my Challenger as well, which have heim joints. The first set of heims in the Hotchkis UCA's only lasted 7k miles. Hotchkis replaced them for me at no charge and sent me the boots that had become available (great customer service!), and I ran another 7k miles onto them. They're not completely toast yet, but I bet they'd only go a few thousand more miles before I have to replace them again. They'll get new heims and boots before the car goes back on the road. So yeah, at the UCA I don't recommend heims, they don't last well on a daily. But at the strut rod, no issues. There's a lot less load on the heim at the strut rod.

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And yes, I drove my Challenger everywhere, and used it for darn near everything. Those adjustable strut rods with heims were on the car for everything...
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I have had the RMS ones on the cuda for years, but granted not many miles in that time. Probably the single greatest improvement in freeing up the front end for drag racing. I will be pulling the front end apart for all new bushings this winter, and I will check them, but I would be surprised if I see any signs of wear.
 
I have the rms ones on our dart. Also have rms upper arms and have run into any of them going bad.

Had rms upper arms on my yellow fart for years and the heim joints were never an issue.
 
Thank you everyone for all the insight/info. looks like I'll go with the qa1 adj. rods. I already purchased their uca's got greaseable pivot pins,new bushings,and the lca reinforcement plates. Now if this damn weather would only cooperate........
 
Heim joints are probably just fine on a car that will see only a few thousand road miles a year and get regular maintenance (although I'll never put them on a Jeep again). Keep them clean and lubricated and you'll be fine. Will they last 150K miles? Doubtful, but do they need to?

The issue with moving the pivot point back towards the arm, which a heim will tend to do, is that the LCA end will move in a tighter arc as the suspension goes up and down. because it moves in an arc, there will be some change in effective length and therefore caster. But since most of the time when we modify the front suspension we increase the wheel rate (bigger bars) and reduce the amount of travel (lowering). I suspect the amount of geometry change is pretty insignificant. The ability to adjust the length of the bars without taking the suspension apart is probably of greater benefit.

Sometimes Ehrenberg gets a little hung up on the little details and lets the "perfect" be the enemy of the "probably good enough."
 
Heim joints are probably just fine on a car that will see only a few thousand road miles a year and get regular maintenance (although I'll never put them on a Jeep again). Keep them clean and lubricated and you'll be fine. Will they last 150K miles? Doubtful, but do they need to?

The issue with moving the pivot point back towards the arm, which a heim will tend to do, is that the LCA end will move in a tighter arc as the suspension goes up and down. because it moves in an arc, there will be some change in effective length and therefore caster. But since most of the time when we modify the front suspension we increase the wheel rate (bigger bars) and reduce the amount of travel (lowering). I suspect the amount of geometry change is pretty insignificant. The ability to adjust the length of the bars without taking the suspension apart is probably of greater benefit.

Sometimes Ehrenberg gets a little hung up on the little details and lets the "perfect" be the enemy of the "probably good enough."
To some extent yes, You will minimize the pitfalls EBooger speaks of, but He's 100% correct. The strut-rod and LCA are traveling in two different arcs that have to either
converge, diverge, or overlap in a combination of the two. Do Yourself a favor, set the LCA at the proposed angle for the anticipated ride height, with the strut-rod thru the
K-frame and no bushings or washers, slide a small straight-edge down across the holes in the frame touching the rod....then wrap a piece of masking tape at that point.
Then work the LCA thru it's range of travel & watch the end of that rod, there has to be some give there, with or without the links & regardless of the shift in pivot point.
It changes angle, rolls, & moves in and out....that's just the way it is with that set-up. With big bars avg. suspension travel is definitely reduced, and so too are the less
desirable effects, but they're still there. Pivots with just enough cushion up frt. is the ideal set-up to balance precision & give.
 
I agree with all. Ricks point about the shorter did tighter arc is well taken. However, these statements need to be backed up with at least a little science. All that is needed is the length of the rods and the rest is math. Since I have been using these type heim jointed strut rods for years, I agree, the stiffer bars and reduced travel minimizes the potential change in toe through the suspension travel. My guess is its minimal. As far as the life of the heim in this position who cares. The limited usage of these cars can take 10k miles and spread that over yrs.
 
Like I said, the heims on my adjustable strut rods have done well over 60k miles without any significant wear. Those are year round, all weather miles. The set on my Challenger will do 100k miles no problem IMHO. Now, that’s at the strut rod, that hasn’t been my experience with heims at the UCA’s. But adjustable strut rods with heims are not track only parts, they’re fine for daily drivers and they'll outlast a lot of OE bushings. Including OE strut rod bushings.

The caster change argument against the adjustable strut rods is a theoretical exercise in futility. First, has anyone arguing it’s a problem even stopped to consider that there’s significant caster change in the original strut rods because of the amount of give in the bushings? Hard braking, hard acceleration, cornering loads, they all collapse and expand the strut rod bushings, allowing the LCA to move fore/aft, which changes the caster even without consideration for the separate arcs of the LCA and strut rod. That’s part of the reason why there’s adjustable strut rods on the market to begin with!!! Because the OE strut rods and bushings allow for slop.

Yes, there’s a little caster change that has to happen because of the differences in the arcs of travel for the LCA and the strut rod. But I’ve sat there and cycled my suspension through its full range of travel. And I’ve done it over and over again, all to tune out any binding and slop. And let me tell you, there’s no significant fore/aft movement in the LCA in that range. Yes, my car is lowered, yes, the suspension travel has been reduced. But if there’s just about nothing in the way of change in that range, I can’t see it being worse than the OE bushings even for a car with a more stock range of travel.

Until I see actual numbers showing that there’s enough caster change to be a problem, AND it’s actually worse than using OE parts that also definitely contribute to some caster change, it’s BS just like e-burgers assessment of the FMJ spindles.

I know for a fact it’s not a problem on my car. Which means I’d bet it’s not a significant issue on most of the cars that will be running adjustable strut rods to begin with, because most of those cars will have some degree of larger torsion bars and reduced suspension travel.
 
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