LCA Bushings and Other Bushings

[72bluNblu]

This I do know. Before I actually used Poly bushing I had several emails with 72nublu to make sure I was understanding what he is saying.

Then I used the poly bushings and QA1 adjustable struts rods. It is physically impossible for the LCA to move on the pin, let alone slide off of it or even partially off of it. IMPOSSIBLE. A foot brake car can’t force the LCA a off the pin, nor can a trans brake car. It’s IMPOSSIBLE for the LCA to move if the strut rod is on the LCA and frame and correctly adjusted. The LCA can not move unless the strut rod stretches, and that would be impossible.

I can say that at this point no matter what bushing I use it will always get adjustable strut rods. They are relatively inexpensive and they are so far superior to the OE units it’s not even close.

Yes, but you've actually installed all of those parts and understand how they work now. Especially the strut rods, it's amazing how much slop in the factory suspension comes from the factory strut rods.

Yall keep talking about "if the strut rods are adjusted correctly". Exactly WHAT do you call "correct" adjustment? I'm curious, because I plan on using the adjustable QA1 strut rods. Thanks.

The strut rod and the LCA both move in separate arcs, at an angle to each other. So, the strut rod has to be the right length so that the LCA can move freely up and down without binding through its range of travel.

With an adjustable strut rod, you tune the length of the strut rod and then cycle the LCA up and down until you have the length of the strut rod set so there's no binding in the range of travel your LCA will have.

The factory got around doing this by using those big sloppy rubber bushings, if the strut rod isn't exactly the right length (because there are tolerances on everything and the factory tolerances weren't that tight) then the rubber just allows the strut rod to move some. But that in turn lets the LCA move around some.

Last time I checked the adjustable strut with the swivel holds less then the solid strut for movement at the K-member. You all can use what ever your happy with. There are applications where a those bushings are good to use not on a mopar LCA . And who ever drills that pin to lube it good luck. Why would you have to lube that bushing if it don't move on the pin. LMFAO. Just like the OEM strut bushings with the shear sleeve that you all said were NA . Just bought another set.

See, posts like this just show you don't understand the motion of the suspension or how the poly LCA bushings function. The poly LCA bushing spins on the pivot pin. That's why it has to be lubricated. The factory bushings just flex, and then tear if they flex too far. But the motion of the LCA has to flex the rubber, and that adds resistance. The further the LCA moves up or down, the more resistance there is from the OE rubber bushings. That stores energy, which effects how the suspension reacts. Poly doesn't do that, it reacts the same way regardless of the position of the LCA, for more consistent handling.

Firm Feel has been making LCA pivot pins that are drilled for decades and selling them to guys that race. Their knowledge of Mopar suspension and handling far exceeds yours. So yeah, good luck with that nonsense.

Awhile back we were not allowed to use the QA1 strut rods but they allow them now. I’ll be looking into that.
Just a thought, why not add another rod to the front of the strut (at k-frame) then back to the lca close to the pivot, triangulated, arm would never move either way then.

There's no reason for it, and it would add another arc that moves perpendicular to the motion of the LCA, so, it would just add more binding.

All of the forces that act on the suspension come from the wheel. That is translated into the ball joints, and into the control arms. The strut rod is located right next to the lower ball joint for that reason, it stops the ball joint from moving forward and backward. If the LCA isn't moving around at the ball joint end, it won't move around at the pivot end. There's no leverage from the ball joint end to act on the pivot end because it's controlled by the strut rod at that end.

At the pivot, or torsion bar end, the only significant forces acting on the pivot are rotational. If the LCA is moving around at the pivot end that motion is coming from the ball joint end. And in this case, that would mean that the strut rod is allowing the LCA to move backward. If you have adjustable strut rods tuned to the correct length, that doesn't happen. If you have big sloppy factory strut rod bushings, that can happen some as the bushings compress.

 

[Ironracer]

Yes, but you've actually installed all of those parts and understand how they work now. Especially the strut rods, it's amazing how much slop in the factory suspension comes from the factory strut rods.



The strut rod and the LCA both move in separate arcs, at an angle to each other. So, the strut rod has to be the right length so that the LCA can move freely up and down without binding through its range of travel.

With an adjustable strut rod, you tune the length of the strut rod and then cycle the LCA up and down until you have the length of the strut rod set so there's no binding in the range of travel your LCA will have.

The factory got around doing this by using those big sloppy rubber bushings, if the strut rod isn't exactly the right length (because there are tolerances on everything and the factory tolerances weren't that tight) then the rubber just allows the strut rod to move some. But that in turn lets the LCA move around some.



See, posts like this just show you don't understand the motion of the suspension or how the poly LCA bushings function. The poly LCA bushing spins on the pivot pin. That's why it has to be lubricated. The factory bushings just flex, and then tear if they flex too far. But the motion of the LCA has to flex the rubber, and that adds resistance. The further the LCA moves up or down, the more resistance there is from the OE rubber bushings. That stores energy, which effects how the suspension reacts. Poly doesn't do that, it reacts the same way regardless of the position of the LCA, for more consistent handling.

Firm Feel has been making LCA pivot pins that are drilled for decades and selling them to guys that race. Their knowledge of Mopar suspension and handling far exceeds yours. So yeah, good luck with that nonsense.



There's no reason for it, and it would add another arc that moves perpendicular to the motion of the LCA, so, it would just add more binding.

All of the forces that act on the suspension come from the wheel. That is translated into the ball joints, and into the control arms. The strut rod is located right next to the lower ball joint for that reason, it stops the ball joint from moving forward and backward. If the LCA isn't moving around at the ball joint end, it won't move around at the pivot end. There's no leverage from the ball joint end to act on the pivot end because it's controlled by the strut rod at that end.

At the pivot, or torsion bar end, the only significant forces acting on the pivot are rotational. If the LCA is moving around at the pivot end that motion is coming from the ball joint end. And in this case, that would mean that the strut rod is allowing the LCA to move backward. If you have adjustable strut rods tuned to the correct length, that doesn't happen. If you have big sloppy factory strut rod bushings, that can happen some as the bushings compress.

The way you explained that, I can actually perfectly Envision everything like it would be if you were going down the road. Well put, and thank you

 

[Ironracer]

I make precision fit pins and delrin bushings. I purposely did not gun drill them for grease as I didn’t want to weaken the pin. A majority of the suspension load is on the lower arm, so this isn’t a place to experiment. I’ve even gone as far as Rockwell testing the originals and using the same material. This ensures safety in an impact causing the pin to bend not break. The material is more expensive to do this.
I’ve also made sure there is a degree of interference fit to compensate for temperature changes and break in wear. Delrin lasts longer than any Indian or Chinese rubber bushing and offers precision movement. I’ve installed many sets besides selling them and never experienced vibration in the steering wheel. Pushing the t bars all they way forward and drilling the socket for a set screw may satisfy some of people’s concerns. This is one mod that’s a nice upgrade from all the low quality rubber parts on the market. However, I respect the fact that upgraded handling is not everyone’s goal.

Do your bushings slip fit on your pins, then slip in the LCA? Or is a press required?

 

[yellow rose]

Yall keep talking about "if the strut rods are adjusted correctly". Exactly WHAT do you call "correct" adjustment? I'm curious, because I plan on using the adjustable QA1 strut rods. Thanks.

The correct adjustment is in the instructions. Regardless of all the bullshit, there is no way anyone can pull the LCA off the pin with an adjustable strut rod. Anyone who says they can are, at best, BULLSHITTING.

 

[yellow rose]

Last time I checked the adjustable strut with the swivel holds less then the solid strut for movement at the K-member. You all can use what ever your happy with. There are applications where a those bushings are good to use not on a mopar LCA . And who ever drills that pin to lube it good luck. Why would you have to lube that bushing if it don't move on the pin. LMFAO. Just like the OEM strut bushings with the shear sleeve that you all said were NA . Just bought another set.

You have to lube the pin because the LCA rotates on the pin with poly bushings. It doesn’t do that with the OE bushing.

The fact that has to be called out to you says you either just don’t know what the frick you are talking about or you just want to be a prick and make everyone think you are right when you clearly are not.

 

[Ceedawg]

Yes, but you've actually installed all of those parts and understand how they work now. Especially the strut rods, it's amazing how much slop in the factory suspension comes from the factory strut rods.



The strut rod and the LCA both move in separate arcs, at an angle to each other. So, the strut rod has to be the right length so that the LCA can move freely up and down without binding through its range of travel.

With an adjustable strut rod, you tune the length of the strut rod and then cycle the LCA up and down until you have the length of the strut rod set so there's no binding in the range of travel your LCA will have.

The factory got around doing this by using those big sloppy rubber bushings, if the strut rod isn't exactly the right length (because there are tolerances on everything and the factory tolerances weren't that tight) then the rubber just allows the strut rod to move some. But that in turn lets the LCA move around some.



See, posts like this just show you don't understand the motion of the suspension or how the poly LCA bushings function. The poly LCA bushing spins on the pivot pin. That's why it has to be lubricated. The factory bushings just flex, and then tear if they flex too far. But the motion of the LCA has to flex the rubber, and that adds resistance. The further the LCA moves up or down, the more resistance there is from the OE rubber bushings. That stores energy, which effects how the suspension reacts. Poly doesn't do that, it reacts the same way regardless of the position of the LCA, for more consistent handling.

Firm Feel has been making LCA pivot pins that are drilled for decades and selling them to guys that race. Their knowledge of Mopar suspension and handling far exceeds yours. So yeah, good luck with that nonsense.



There's no reason for it, and it would add another arc that moves perpendicular to the motion of the LCA, so, it would just add more binding.

All of the forces that act on the suspension come from the wheel. That is translated into the ball joints, and into the control arms. The strut rod is located right next to the lower ball joint for that reason, it stops the ball joint from moving forward and backward. If the LCA isn't moving around at the ball joint end, it won't move around at the pivot end. There's no leverage from the ball joint end to act on the pivot end because it's controlled by the strut rod at that end.

At the pivot, or torsion bar end, the only significant forces acting on the pivot are rotational. If the LCA is moving around at the pivot end that motion is coming from the ball joint end. And in this case, that would mean that the strut rod is allowing the LCA to move backward. If you have adjustable strut rods tuned to the correct length, that doesn't happen. If you have big sloppy factory strut rod bushings, that can happen some as the bushings compress.

“There's no reason for it, and it would add another arc that moves perpendicular to the motion of the LCA, so, it would just add more binding”
Not if the strut pivot is in line with the centerline pin in the lca

 

[72bluNblu]

Do your bushings slip fit on your pins, then slip in the LCA? Or is a press required?

The Delrin bushings are a press fit into the LCA, similar to the old style bushings. The Delrin replaces the original outer shell. The pivot pins are then a tight slip fit into the bushing. Maybe a little tighter than with the poly bushing/pin, but that will depend on the pin you use. Mine were a very tight slip fit, but still a slip fit. Just like the poly bushings, the Delrin bushing will rotate on the pivot pin.

“There's no reason for it, and it would add another arc that moves perpendicular to the motion of the LCA, so, it would just add more binding”
Not if the strut pivot is in line with the centerline pin in the lcaView attachment 1715739517

What are you attaching the extra rod to? The strut rod or the K frame?

If it’s attached to the K frame, the end that attaches to the LCA will still track in an arc as it moves up and down because it’s fixed at one end and free at the other. And because it’s perpendicular to the LCA, the LCA moves straight up and down relative to that rod. The further the LCA moves up and down, the more arc the additional rod will travel in, pulling and pushing on the LCA.

If you’re triangulating between the strut rod and the LCA, you have to realize that the strut rod and LCA are not the same length. So, the end attached to the original strut rod and the end attached to the LCA will not move the same distances up and down.

The ball joint on the LCA travels in an arc perpendicular to the frame as the LCA moves up and down. The end of the strut rod travels in an arc perpendicular to its attachment on the K frame, which is at an angle to the ball joint arc. The LCA and strut rod are not equal length. That’s why checking for binding and tuning the length of the strut rod is necessary with the adjustable strut rods, you have to manage those arcs for the suspension travel range on YOUR car. So adding an extra strut, without adding binding, is a complicated affair.

And, there’s no need for it. There’s only one person here that thinks the strut rod doesn’t adequately control the forward and backward motion of the LCA on the pin. And he’s wrong.

I’ve spent a lot of time tuning the length of the strut rods on my cars as I’ve made changes to my LCA bushings, my LCA’s, my UCA’s, etc. Every time I make a significant change to my suspension I check for binding. A properly adjusted strut rod length does not allow the LCA movement described by OMM. If it did, my alignment would change every time I stepped on my brakes. Instead, my alignments hold without any issue. Not to mention, the wild swings in caster angle would make the car a beast to control with 275’s up front.

 

[Ceedawg]

The Delrin bushings are a press fit into the LCA, similar to the old style bushings. The Delrin replaces the original outer shell. The pivot pins are then a tight slip fit into the bushing. Maybe a little tighter than with the poly bushing/pin, but that will depend on the pin you use. Mine were a very tight slip fit, but still a slip fit. Just like the poly bushings, the Delrin bushing will rotate on the pivot pin.




What are you attaching the extra rod to? The strut rod or the K frame?

If it’s attached to the K frame, the end that attaches to the LCA will still track in an arc as it moves up and down because it’s fixed at one end and free at the other. And because it’s perpendicular to the LCA, the LCA moves straight up and down relative to that rod. The further the LCA moves up and down, the more arc the additional rod will travel in, pulling and pushing on the LCA.

If you’re triangulating between the strut rod and the LCA, you have to realize that the strut rod and LCA are not the same length. So, the end attached to the original strut rod and the end attached to the LCA will not move the same distances up and down.

The ball joint on the LCA travels in an arc perpendicular to the frame as the LCA moves up and down. The end of the strut rod travels in an arc perpendicular to its attachment on the K frame, which is at an angle to the ball joint arc. The LCA and strut rod are not equal length. That’s why checking for binding and tuning the length of the strut rod is necessary with the adjustable strut rods, you have to manage those arcs for the suspension travel range on YOUR car. So adding an extra strut, without adding binding, is a complicated affair.

And, there’s no need for it. There’s only one person here that thinks the strut rod doesn’t adequately control the forward and backward motion of the LCA on the pin. And he’s wrong.

I’ve spent a lot of time tuning the length of the strut rods on my cars as I’ve made changes to my LCA bushings, my LCA’s, my UCA’s, etc. Every time I make a significant change to my suspension I check for binding. A properly adjusted strut rod length does not allow the LCA movement described by OMM. If it did, my alignment would change every time I stepped on my brakes. Instead, my alignments hold without any issue. Not to mention, the wild swings in caster angle would make the car a beast to control with 275’s up front.

You must have not looked at my drawing. The connector is hooked to the strut rod. IF the strut rod PIVOT is not in line with the pin of the lca then there will be two different arcs. Too high the rod will move the lca BACK as it moves up and pull forward as it drops, too low and the opposite. To far in or out and different arcs also. The lca will move! You do understand the principle of a hinge, that’s the perfect geometric plane for the lower control arm. I’ve rotated my lca and the center of the strut rod pivot is slightly inside the k-frame hole. I can see why Chrysler used those rubber biscuits so I don’t like the adjustable struts because it’s center is to far out-off the lca pin centerline. I want all the arcs the same and I’ll figure out a way to make it look right to pass the tech guys, just simple geometry.
One other thing, it don’t matter how long each part is as long as the intersect. Strut can be 4’ and lca 1’ still a triangle.

 

[Oldmanmopar]

The correct adjustment is in the instructions. Regardless of all the bullshit, there is no way anyone can pull the LCA off the pin with an adjustable strut rod. Anyone who says they can are, at best, BULLSHITTING.

You'll eat those words when the video is added. Doesn't the adjustable strut have a swivel. Now What? LMAO

 

[RustyRatRod]

If the strut rod is adjusted to "whatever" the right length is, I'm not understanding how the LCA can slide on the pin. Since the forces that "might" cause that are on the OUTSIDE of the LCA (the tire) and the bushing on the opposite end, I find it difficult to see it sliding on the pin when it has the strut there to hold it, unless there is something WRONG.

If the forces at work "somehow" destroy the poly bushings because of sliding on the pin, then certainly piles and piles of rubber bushings would also have been destroyed, since they are not as hard, and there is also much less surface area since the rubber bushings are much shorter.

At least, that's how it looks "to me". I don't have a dog in the fight on this other than deciding which parts will work best for ME. I am pretty sure after talking to Peter today what those will be.

 

[yellow rose]

You'll eat those words when the video is added. Doesn't the adjustable strut have a swivel. Now What? LMAO

Sure does, but it has to. You do know they have Hemi joints on 4 links right? Same thing. Now what? LMAO

 

[Oldmanmopar]

You have to lube the pin because the LCA rotates on the pin with poly bushings. It doesn’t do that with the OE bushing.

The fact that has to be called out to you says you either just don’t know what the frick you are talking about or you just want to be a prick and make everyone think you are right when you clearly are not.

I thought the pin can't slide out because of its tight fit. If it can turn it can slide. If you lube it it can slide out even easier. Gotha

If you read my post above I said while foot braking the car it pushes the wheel back and in turn forces the arm against the K-member. When launching the pressure release causes the LCA to bounce back which was causing my wheels to bounce front when they came up. Look at the toe change in the video above when the wheels would come up.

This same movement can be seen if you foot brake the car in reverse. The arm moves away from the K-member. The space we measured is 3/8 -1/2 inch as stated above. You can move it back that far with a pry bar on the lift . the torsion bar clip stops the movement. Without the torsion bar in you can pry it off the pin. The arm pivots back on the rubber strut bushing.

I built a lot of mopars over the years and I will never again use anything but OEM style parts. The OEM LCA bushings don't rip if tightened in the factory ride height position. The pin is tightened in the center of the arm travel. You guys that jack them up like they are 4x4's better use poly bushings. LMFAO

Brought a barracuda home with poly and adjustable struts. I'll get some picks on the lift when it comes in. I finally took the car for a ride the car wonders at high speed. We are tearing all the aftermarket junk out and lowering the car to stock ride height. It is way to high for comfort and the poly junk and struts have to go. Yeah it has all the things you all are talking about. What a mess.

 

[yellow rose]

If the strut rod is adjusted to "whatever" the right length is, I'm not understanding how the LCA can slide on the pin. Since the forces that "might" cause that are on the OUTSIDE of the LCA (the tire) and the bushing on the opposite end, I find it difficult to see it sliding on the pin when it has the strut there to hold it, unless there is something WRONG.

If the forces at work "somehow" destroy the poly bushings because of sliding on the pin, then certainly piles and piles of rubber bushings would also have been destroyed, since they are not as hard, and there is also much less surface area since the rubber bushings are much shorter.

At least, that's how it looks "to me". I don't have a dog in the fight on this other than deciding which parts will work best for ME. I am pretty sure after talking to Peter today what those will be.

You have a better understanding than most do. Again, as several have pointed out...there is no way you could possibly move the LCA off the pin with a correctly adjusted strut rod. Like I said it’s impossible for it to move. IMPOSSIBLE.

What I do know is some guys can break a bowling ball in a sand box with no tools. There are guys who can’t follow simple instructions.

I would suggest going to an autocross or some kind of road race where stock chassis cars are running and see how many of those guys are running stock strut rods and rubber bushings. I think unless the rules mandate stock strut rods there wouldn’t be anyone not using them.

BTW, if you’ve ever seen a drag car with a strut front end, you’ll notice they use a similar strut rod. With heim joints. Pro Stock, Pro Mod, Comp Eliminator...all of them run struts and heim joints.

They must all be stupid.

 

[yellow rose]

I thought the pin can't slide out because of its tight fit. If it can turn it can slide. If you lube it it can slide out even easier. Gotha

If you read my post above I said while foot braking the car it pushes the wheel back and in turn forces the arm against the K-member. When launching the pressure release causes the LCA to bounce back which was causing my wheels to bounce front when they came up. Look at the toe change in the video above when the wheels would come up.

This same movement can be seen if you foot brake the car in reverse. The arm moves away from the K-member. The space we measured is 3/8 -1/2 inch as stated above. You can move it back that far with a pry bar on the lift . the torsion bar clip stops the movement. Without the torsion bar in you can pry it off the pin. The arm pivots back on the rubber strut bushing.

I built a lot of mopars over the years and I will never again use anything but OEM style parts. The OEM LCA bushings don't rip if tightened in the factory ride height position. The pin is tightened in the center of the arm travel. You guys that jack them up like they are 4x4's better use poly bushings. LMFAO

Brought a barracuda home with poly and adjustable struts. I'll get some picks on the lift when it comes in. I finally took the car for a ride the car wonders at high speed. We are tearing all the aftermarket junk out and lowering the car to stock ride height. It is way to high for comfort and the poly junk and struts have to go. Yeah it has all the things you all are talking about. What a mess.

View attachment 1715739574

View attachment 1715739575

You can’t be that thick. It’s not that hard to grasp unless you want to not get it. Just because the LCA pivots on the pin doesn’t mean it can slide off the pin.

So how does the strut rod allow the LCA to slide off the pin? It’s a FIXED LENGTH and it doesn’t flex.

Even a semi retarded third grader can see how what you claim is not only fantastical it’s IMPOSSIBLE.

 

[Ironracer]

I can be so damn meticulous that's another thing I was concerned about I didn't know if they just mailed those off to you if you turn the screw until they flopped around or how the hell you did it

 

[Ironracer]

I thought the pin can't slide out because of its tight fit. If it can turn it can slide. If you lube it it can slide out even easier. Gotha

If you read my post above I said while foot braking the car it pushes the wheel back and in turn forces the arm against the K-member. When launching the pressure release causes the LCA to bounce back which was causing my wheels to bounce front when they came up. Look at the toe change in the video above when the wheels would come up.

This same movement can be seen if you foot brake the car in reverse. The arm moves away from the K-member. The space we measured is 3/8 -1/2 inch as stated above. You can move it back that far with a pry bar on the lift . the torsion bar clip stops the movement. Without the torsion bar in you can pry it off the pin. The arm pivots back on the rubber strut bushing.

I built a lot of mopars over the years and I will never again use anything but OEM style parts. The OEM LCA bushings don't rip if tightened in the factory ride height position. The pin is tightened in the center of the arm travel. You guys that jack them up like they are 4x4's better use poly bushings. LMFAO

Brought a barracuda home with poly and adjustable struts. I'll get some picks on the lift when it comes in. I finally took the car for a ride the car wonders at high speed. We are tearing all the aftermarket junk out and lowering the car to stock ride height. It is way to high for comfort and the poly junk and struts have to go. Yeah it has all the things you all are talking about. What a mess.

View attachment 1715739574

View attachment 1715739575

My concern is that rubber is junk today. Has been for years. .. not to be insulting I'm not referring just to the rubber lower control arm bushings or any suspension Part I'm talking about with rubber as the material

 

[Oldmanmopar]

You can’t be that thick. It’s not that hard to grasp unless you want to not get it. Just because the LCA pivots on the pin doesn’t mean it can slide off the pin.

So how does the strut rod allow the LCA to slide off the pin? It’s a FIXED LENGTH and it doesn’t flex.

Even a semi retarded third grader can see how what you claim is not only fantastical it’s IMPOSSIBLE.

Evidently you never tried it we did. The bushing on the 73 up cars flexes enough to do it. We first noticed it when looking at the car after backing it into the pit stall the both pins were pulled out of the bushings. . My son got in the car and put it in gear and pulled forward and they went back in. Several members from this site were at the track with us and saw the same thing. Before you open your big fucken mouth maybe you should have tried it or waited for the video. The barracuda does the same thing. Your trying to make and *** out of me and you have no clue. You just think you know it all like Blownbyblew.

If I would say the sky is blue you would say its pink. Its always been that way . Besides that unless your restoring a car for street only your better off with a aftermarket suspension with a rack & pinion. I sell complete factory takeout suspensions rebuilt ready to install with 340 70-72 k members with factory LCA supports also 73,74 they are different then 318 style. I only have a couple left. 69 back are different. The washer welded on the front designates it is a braced K-member.
I was wondering if you all know why they are braced?

 

[Oldmanmopar]

My concern is that rubber is junk today. Has been for years. .. not to be insulting I'm not referring just to the rubber lower control arm bushings or any suspension Park I'm talking about rubber as the material

I know what you are saying. even some tires are junk. We rub Dawn dish washing liquid in Hoosiers . Keeps them from seeping air. We also run Nitrogen in them so they don't change diameter from heat. look for those three letters USA

 

[RustyRatRod]

You can’t be that thick. It’s not that hard to grasp unless you want to not get it. Just because the LCA pivots on the pin doesn’t mean it can slide off the pin.

So how does the strut rod allow the LCA to slide off the pin? It’s a FIXED LENGTH and it doesn’t flex.

Even a semi retarded third grader can see how what you claim is not only fantastical it’s IMPOSSIBLE.

Here is my only point of "misinderstanding". The LCA travels up and down perpendicular to the LCA shaft center line. So, that means the strut rod end must travel in a arc, since it is fixed to the LCA end. This is the reason for the rubber bushings. To allow "just enough" fore and aft with the strut rod at the K frame where it installs in the bushings. So now we're talking about replacing the stock strut rods with a swivel (which I want to do).

So now we have installed a swivel strut rod totally FIXED on both ends, with no bushings. So, my question now is, WHERE is the fore and aft movement NOW? Since the strut rod now is totally fixed with no bushings, it has no way to allow that small bit of fore and aft movement going through the arc. I can only assume that small amount of fore and aft movement is transferred to "whatever" LCA bushing we use and that now the LCA has that same amount of fore and aft movement. RIGHT?

 

[Ironracer]

Here is my only point of "misinderstanding". The LCA travels up and down perpendicular to the LCA shaft center line. So, that means the strut rod end must travel in a arc, since it is fixed to the LCA end. This is the reason for the rubber bushings. To allow "just enough" fore and aft with the strut rod at the K frame where it installs in the bushings. So now we're talking about replacing the stock strut rods with a swivel (which I want to do).

So now we have installed a swivel strut rod totally FIXED on both ends, with no bushings. So, my question now is, WHERE is the fore and aft movement NOW? Since the strut rod now is totally fixed with no bushings, it has no way to allow that small bit of fore and aft movement going through the arc. I can only assume that small amount of fore and aft movement is transferred to "whatever" LCA bushing we use and that now the LCA has that same amount of fore and aft movement. RIGHT?

I thought the heim joint would deal with that. It sounds like we're both leaning toward going the same direction with our respective vehicles, so just like you, I'm trying to do research and I appreciate all of the input from everyone on here

 

[RustyRatRod]

I thought the heim joint would deal with that. It sounds like we're both leading scorers going the same direction with our respective vehicles so just like you I'm trying to do research and I appreciate all of the input from everyone on here

The heim joint is a fixed swivel. In order for it to "deal with that" it would need to have a small bit of fore and aft. It does not. The LCA end of the swivel strut rod must travel in an arc. It has no choice since there are no bushings at the K frame.

 

[yellow rose]

Evidently you never tried it we did. The bushing on the 73 up cars flexes enough to do it. We first noticed it when looking at the car after backing it into the pit stall the both pins were pulled out of the bushings. . My son got in the car and put it in gear and pulled forward and they went back in. Several members from this site were at the track with us and saw the same thing. Before you open your big fucken mouth maybe you should have tried it or waited for the video. The barracuda does the same thing. Your trying to make and *** out of me and you have no clue. You just think you know it all like Blownbyblew.

If I would say the sky is blue you would say its pink. Its always been that way . Besides that unless your restoring a car for street only your better off with a aftermarket suspension with a rack & pinion. I sell complete factory takeout suspensions rebuilt ready to install with 340 70-72 k members with factory LCA supports also 73,74 they are different then 318 style. I only have a couple left. 69 back are different. The washer welded on the front designates it is a braced K-member.
I was wondering if you all know why they are braced?

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Ok, just so I’m clear on this. Are you saying you used poly LCA bushings and OE strut rods? Or did you use poly bushings and some brand of adjustable strut rod.

Just trying to understand what you are talking about. BTW, the sky IS blue. I don’t question you when you say something that makes sense.

 

[Ironracer]

The heim joint is a fixed swivel. In order for it to "deal with that" it would need to have a small bit of fore and aft. It does not. The LCA end of the swivel strut rod must travel in an arc. It has no choice since there are no bushings at the K frame.

Yes I guess. As a carpenter I can see that. if you have it straight out in one position ( I'll call it " level" but it aint) as it goes up and down the rod would have to be lengthened in order for the lower control arm to travel in the exact same spot up or down

 

[RustyRatRod]

Yes I guess it's a carpenter I can see that if you have it straight out in one position as it goes up and down the rod would have to be lengthened in order for the lower control arm to travel in the exact same spot up or down

Yes. The "middle" of the arc would be the "longest" travel. Then going up with the control arm or down would effectively "shorten" the strut rod and that movement would have to be transferred "somewhere". The only place we have now is the LCA bushing. It may well be it's such a "small amount" of fore and aft movement that it doesn't matter. But an arc is an arc.

 

[yellow rose]

Here is my only point of "misinderstanding". The LCA travels up and down perpendicular to the LCA shaft center line. So, that means the strut rod end must travel in a arc, since it is fixed to the LCA end. This is the reason for the rubber bushings. To allow "just enough" fore and aft with the strut rod at the K frame where it installs in the bushings. So now we're talking about replacing the stock strut rods with a swivel (which I want to do).

So now we have installed a swivel strut rod totally FIXED on both ends, with no bushings. So, my question now is, WHERE is the fore and aft movement NOW? Since the strut rod now is totally fixed with no bushings, it has no way to allow that small bit of fore and aft movement going through the arc. I can only assume that small amount of fore and aft movement is transferred to "whatever" LCA bushing we use and that now the LCA has that same amount of fore and aft movement. RIGHT?

What happens is that the heim joint allows for moving through an arc. When you install the adjustable strut rod you set the length at ride height and as 72nublu said you have to move the LCA up and down to insure there isn’t any binding. If there is, you have the rod the wrong length or something else.

The heim has to be installed so that the joint is verticals, and not parallel to the ground. IOW’s, the bolt that attaches the heim to the frame must be running left to right and not up and down. If you do that, the heim allows the strut rod to move through an arc without binding or pulling or pushing on the LCA.

And there is no way on God’s green earth that the LCA can come off the pin, even a skosh if the strut rod is installed correctly.

Like I said, even if I was going to use rubber LCA bushings I would still use adjustable strut rods.