LCA Bushings and Other Bushings
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.
