Lower control arm stiffening plates?

[Eric F]

I’ve been slowing converting from the rubber bushings on my 70 Road Runner to urethane. Rears I installed energy suspension/Hotchkis in the rear suspension. Upper control arms in installed Prothane bushing and sway bar bushings. My next and last to be installed are the lower control arms with strut rod bushings that are from Prothane. I was thinking adding the lower control arm stiffing plates. Thoughts?
No im not building a road racer. I like the ride the urethane bushings installed. No none of them squeak. I know someone will comment about I should only install rubber. Don’t care.

 

[j-c-c-62]

"Thoughts?"
If indeed they can be justified, I am curious how one decides what is the needed correct thickness?

You asked a fair I believe sincere question, unfortunately no honest response I can give will not create a lot of strife.

 

[1KoolBee]

Huge subject for debate on this site. Not hard to do if you can mig weld. Not expensive. Necessary? Maybe, flex is unquantified, failures are rare. Cheap insurance? Definitely, I put them on my GTX project.

Bottom line, build it the way you want. Everyone else’s opinion, including mine, is irrelevant. Actual experience’s are the only thing of any real value here.

 

[j-c-c-62]

That didn't take long.



You should have left in the "Engineering Karens", that was a nice touch.

 

[RemCharger]

The factory control arm is a pretty robust piece. Look at 73, they upgraded by downgrading to a wimpier part. That tells you something.

 

[gkent]

If the pivot wobbles in the LCA then the plates are a good idea. Installation is a breeze if you have a mig. Buying the pre-made plates is the easy route and they are inexpensive. If you decide to go that route be sure to clamp the two halves of the LCA together to take out any slop in the pivot - then weld the plates on. They will need to be hammered to match the contours og the LCAs - no big deal ... tack, hammer, tack, hammer, etc..

As for the poly bushings. That's the one place I would NOT use them - they do not "press" onto the pins as the stock ones do. They may be fine for a track car but you want that press fit on a driver.

 

[BeepBeepRR]

Ive always had Poly bushings squeek.. Maybe its just a me problem but never liked them.

 

[Eric F]

Ive always had Poly bushings squeek.. Maybe its just a me problem but never liked them.

The ones in the 80’s and 90’s always squeaked. The ones I’ve been installing come with very sticky clearish color grease. The ones from the 80’s and 90’s used clear grease that seemed to be the same consistency are regular wheel bearing/chassis grease.maybe they have learned.

 

[GTXDAN]

Chris Birdsong sells them on his website for $20 + post

junkerup

 

[gkent]

Americans are a funny breed. They'll bitch and moan about a Chinese copy but if an American copies another American's product and sells at a lower price, its ok !!!

 

[bobsgtx]

My 2 cents. If LCA pivots are loose, tighten with plates. No opinion on bushing material.

 

[Photon440]

The ones in the 80’s and 90’s always squeaked. The ones I’ve been installing come with very sticky clearish color grease. The ones from the 80’s and 90’s used clear grease that seemed to be the same consistency are regular wheel bearing/chassis grease.maybe they have learned.

The new lube is likely silicon grease. You can also use dielectric grease.

 

[RemCharger]

The new lube is likely silicon grease. You can also use dielectric grease.

It's similar, but the stuff they send is much more viscous.

 

[Kern Dog]

You asked a fair I believe sincere question, unfortunately no honest response I can give will not create a lot of strife.

I have given you a hard time for being critical of some things that have become popular for enthusiasts to do but in the interest of fairness, I am willing to revisit your concerns.
If I recall, you questioned the value of certain things that enthusiasts have done in the interest of improving durability and such in regards to suspension and steering.
I may have just dismissed your opinions given my youthful arrogance and not given you a chance to explain.
If your assertions are that some “modifications” are pointless and only add weight, I am willing to accept that that is possible.
For one, I think that it might be true that welding stiffener plates to a car with LCAs that show no abnormal wear or damage, for use in a car that will not be pushed very hard…the plates may not make any improvement at all since no weakness currently exists.
Regarding the switch from 9/16” tie rod gear to the 11/16” stuff, the same argument applies.
It may be that some guys like the feeling of making improvements even if the car is never pushed to the point of highlighting any advantages the changes may give.
I welded up all the seams in my K member, added gussets and reinforcements to the steering box mounts too. My rationale was that this area flexes with the car sitting still so it must flex more under duress.
I do not know of any legitimate engineering that supports the LCA stiffening plates but given my experience in construction, I do know that even thin sheets of plywood nailed over a 2x4 wall do increase the rigidity of the wall by a huge amount. I welded THICK plates to my red car but have since stepped it down to .090 thick sheets for subsequent vehicles. I am building a 4 door Dart that may not even get them at all.
The 11/16” tie rod upgrade ?
It was believed that the bigger parts were far more likely to resist deflection but I wonder if the weak links were the sleeves themselves. Maybe using solid tie rod sleeves instead of the stock slotted ones is enough.
We can disagree but I personally welcome a discussion on the merits or drawbacks.

 

[j-c-c-62]

I have given you a hard time for being critical of some things that have become popular for enthusiasts to do but I in the interest of fairness, I am willing to revisit your concerns.
If I recall, you questioned the value of certain things that enthusiasts have done in the interest of improving durability and such in regards to suspension and steering.
I may have just dismissed your opinions given my youthful arrogance and not given you a chance to explain.
If your assertions are that some “modifications” are pointless and only add weight, I am willing to accept that that is possible.
For one, I think that it might be true that welding stiffener plates to a car with LCAs that show no abnormal wear or damage, for use in a car that will not be pushed very hard…the plates may not make any improvement at all since no weakness currently exists.
Regarding the switch from 9/16” tie rod gear to the 11/16” stuff, the same argument applies.
It may be that some guys like the feeling of making improvements even if the car is never pushed to the point of highlighting any advantages the changes may give.
I welded up all the seams in my K member, added gussets and reinforcements to the steering box mounts too. My rationale was that this area flexes with the car sitting still so it must flex more under duress.
I do not know if any legitimate engineering that supports the LCA stiffening plates but given my experience in construction, I do know that even thin sheets of plywood nailed over a 2x4 wall do increase the rigidity of the wall by a huge amount. I welded THICK plates to my red car but have since stepped it down to .090 thick sheets for subsequent vehicles. I am building a 4 door Dart that may not even get them at all.
The 11/16” tie rod upgrade ?
It was believed that the bigger parts were far more likely to resist deflection but I wonder if the weak links were the sleeves themselves. Maybe using solid tie rod sleeves instead of the stock slotted ones is enough.
We can disagree but I personally welcome a discussion on the merits or drawbacks.

I agree with nearly all the above, the problem in general seems based on past experiences, when opposing a common perception, discussions devolve into personal attacks, which I am well used to, but little gets learned and the whole discussion becomes pointless to the topic at hand. That is what disappoints me.
I should also add, if I knew everything, I would not be here. I am also here to learn, and if a line of thinking becomes passionate, fine, great, means someone cares, and I welcome the scrutiny. It's just my perception of having to walk on eggshells all the time is so limiting. Disagreeing is good, with shared reason, IMO. And Kern, it seems when we do disagree, you eventually come around. Don't change.

I do have to call out the term (now deleted) I first read in this thread referring to "Engineering Karens", is a classic and a keeper.

 

[threewood]

Cheap and easy to do. There are no downsides to using the plates.

 

[j-c-c-62]

Americans are a funny breed. They'll bitch and moan about a Chinese copy but if an American copies another American's product and sells at a lower price, its ok !!!

Oh, man, how close that hits to home today, you have no idea.
I have a very limited really neat item I am almost ready to offer any day now that has been significantly upgraded, that is, I can hear it now, "a rip off copy". I'm personally rather sensitive to that accusation as in my niche profession I have had that happen to me numerous times. Best consolation, copies are rarely better than the original and that "flattery" analogy does nothing to improve one's bank account. That downside will not apply in my rendition. Stay tuned.

 

[Photon440]

Cheap and easy to do. There are no downsides to using the plates.

Probably easy to do if you happen to already have the arms removed from the car. Otherwise... PST on this site offered instructions for them: PST's Stiffening Plates Install

 

[threewood]

Probably easy to do if you happen to already have the arms removed from the car. Otherwise... PST on this site offered instructions for them: PST's Stiffening Plates Install

I did mine on the car. Off would be cleaner.

 

[Rishi]

Cheap and easy to do. There are no downsides to using the plates.

"The look" has a downside. Albeit small, but it's an obvious modification. If my LCA were loose and sloppy, I'd be tempted to replace them. Were the restoration to contain (for example) QA-1 suspension parts, and bolt-on chevy-like chrome parts, then sure, there is no downside to using the plates.