Control arms: What is the benefit to bushing at one end and flex joint at other?

[bobthetj03]

I suspect the bushing would wear away far faster than the housing will.

I would suspect this as well. The joint would fail well before any damage was done to the inside wall of the barrel me thinks.
This is a DF joint with approximately 35K miles of wear.

You'll notice a bit of scuffing around the circumference of the bushing. The OD of the bushing is no less than a new joint. the little bit of scarring is most likely due to me neglecting the maintenance of the joint for 35K. It was dry. there was a small amount of rubber transfer along the inside wall of the barrel in which the joint is housed. Cleaned the surface with a little brake cleaner and there was no evidence of wear of said surface.

 

[StG58]

Another question, what joint does Currie or Savvy run on the KOH rigs? Or desert racing rigs?

Be very careful about equating what works best on a racing rig with what works best on a street / trail rig.

 

[jjvw]

Be very careful about equating what works best on a racing rig with what works best on a street / trail rig.

Why? I'm not necessarily agreeing or disagreeing. I'm fairly certain Savvy uses JJs on their race cars. Does that suggest that a JJ might not be a good choice for daily driving? If so, why?

 

[Gollywomper]

Be very careful about equating what works best on a racing rig with what works best on a street / trail rig.

Yes I understand that. Just curious I guess. The JJ was not developed for the weekend warrior either. It may have evolved into that. Similar to the Anti Rock sway bar, it’s was not developed for the weedend crowd. They both have evolved into what we can now buy. Just curious as to what new advancements have been made, if any.

 

[jjvw]

.... The JJ was not developed for the weekend warrior either. It may have evolved into that. Similar to the Anti Rock sway bar, it’s was not developed for the weedend crowd. They both have evolved into what we can now buy.
....

Who were these things originally developed for? I'm not familiar with the history. Was there a time when only a professional race team could purchase Johnny Joints and an Antirock?

 

[Gollywomper]

I am unsure of the exact origins of devolpment. My reference was they were devolved for Offroad use In mind and have evolved into what they are now. And were designed to fix a specific set of problems, that many don’t have but insist on having the product on their Jeep. Many of us drive around with components that are designed to help off road even though we only spend 10-15% of our Jeep time off road. Does the Anti Rock improve on road handling? But The Weeknd warrior still wants one.

My mistake for using exact product examples. My point was In reference to a lot of product development being race and performance driven.

 

[jjvw]

I am unsure of the exact origins of devolpment. My reference was they were devolved for Offroad use In mind and have evolved into what they are now. And were designed to fix a specific set of problems, that many don’t have but insist on having the product on their Jeep. Many of us drive around with components that are designed to help off road even though we only spend 10-15% of our Jeep time off road. Does the Anti Rock improve on road handling? But The Weeknd warrior still wants one.

Blaine mentioned this earlier. Here is another world where JJs are used.
https://www.streetmusclemag.com/new...r-suspensions-now-offered-with-johnny-joints/
Personally and FWiW, I like my AR on the street more than the stock bar. But I understand why others may not feel the same way.

A piece of advice from a long time ago that I held on to was that if you build your Jeep to perform well on the street, then it will perform well on the trail. I think I have done a decent job doing that.

One of the notable assumptions I often see from people deciding on what parts to choose is that their Jeep is this or that and not something or other. The premise is that a street Jeep is somehow different than one that goes off pavement. That rock crawling performance and driving comfort are mutually exclusive. That Metalcloak bushings are for a weekend fun Jeep, while Johnny Joints are for hardcore use.

If this is at all true, I've built mine wrong.

 

[Gollywomper]

My poorly wrote example was nothing more than a reference of where many of the upgrades we use were developed.

 

[Gollywomper]

Blaine mentioned this earlier. Here is another world where JJs are used.
https://www.streetmusclemag.com/new...r-suspensions-now-offered-with-johnny-joints/

Interesting read, I knew they were envolved In street stuff. Guess I always thought of a JJ as a high flex joint. Guess it is a do it all type. Lol
Was it designed for street from the start? Why a high flex joint for street? Or was it designed for a high flex environment, then was used in a street application?

 

[StG58]

Why? I'm not necessarily agreeing or disagreeing. I'm fairly certain Savvy uses JJs on their race cars. Does that suggest that a JJ might not be a good choice for daily driving? If so, why?

I can make no value judgements on MS, Currie, or any other control arm design. I run stock arms because they fit my needs right now. I have fallen into the trap of using race parts from other manufacturers to address a perceived need that have addressed the need while creating a host of other problems. Those experiences caused me to point out that race = good and street = bad is not always the case.

Enjoying the discussion though.

 

[StG58]

My poorly wrote example was nothing more than a reference of where many of the upgrades we use were developed.

There are lots of good examples were racing technology has been transitioned into street technology. That transition is rarely a direct move though. You didn't provide a poor example.

 

[Don Bulee]

Good quality flex joints transfer no more road noise or vibrations into the interior than a bushing does. The only benefit to having a bushing on one end is the lower cost.

Bushings on both ends flex so poorly they can tear control arm mounting brackets out of their welds. That happened to me with Teraflex's crappy first-generation control arms.

Jerry, in your opinion is it worth it to change one end of the CA to a JJ? something similar to a Camp series from Core 4x4 (see pic below)? having one end with poly bushings and one end with a JJ? and.... in this scenario, where would you put the JJ end? in the axle or in the frame? (daily driver but I try to make it as capable as I can, weekend warrior)

 

[Blackjack]

Jerry, in your opinion is it worth it to change one end of the CA to a JJ? something similar to a Camp series from Core 4x4 (see pic below)? having one end with poly bushings and one end with a JJ? and.... in this scenario, where would you put the JJ end? in the axle or in the frame? (daily driver but I try to make it as capable as I can, weekend warrior)

View attachment 464949

I wish that Core had not made the choice to go poly. The Clevite bushing was a much better choice.

 

[Don Bulee]

I wish that Core had not made the choice to go poly. The Clevite bushing was a much better choice.

I spoke to them, and they told me that there was a lot of quality complaints about the clevite bushing and they were pretty much forzed to remove it from their inventory due to the quantity of people complaining.... and they went full poly....

I have their cheapest tier/series, and I'm planning in upgrade the adjustable end to a JJ, but then again.... is it worth it? it would be 132 bucks for each pair, so I would like to know if the flexing/ride will improve or if I am chasing ghosts...

 

[mrblaine]

I wish that Core had not made the choice to go poly. The Clevite bushing was a much better choice.

I'm going to have to go with them using a cheap knock-off since there is no way they were having the QC issues with actual Clevite bushings based on his response above.

That and they aren't doing anyone any favors with that poly bullshit.

 

[Blackjack]

I spoke to them, and they told me that there was a lot of quality complaints about the clevite bushing and they were pretty much forzed to remove it from their inventory due to the quantity of people complaining.... and they went full poly....

I have their cheapest tier/series, and I'm planning in upgrade the adjustable end to a JJ, but then again.... is it worth it? it would be 132 bucks for each pair, so I would like to know if the flexing/ride will improve or if I am chasing ghosts...

So when you say lowest tier what ends are on those arms?

I'm going to have to go with them using a cheap knock-off since there is no way they were having the QC issues with actual Clevite bushings based on his response above.

That and they aren't doing anyone any favors with that poly bullshit.

I would have to suspect that as well. I ran arms with Clevites on both ends that I cut out of used arms and would still get 4-5 years out of them before they ever stated having issues.

No arguments on that, poly bushings in this application is not a good thing.

 

[freedom_in_4low]

I spoke to them, and they told me that there was a lot of quality complaints about the clevite bushing and they were pretty much forzed to remove it from their inventory due to the quantity of people complaining.... and they went full poly....

I have their cheapest tier/series, and I'm planning in upgrade the adjustable end to a JJ, but then again.... is it worth it? it would be 132 bucks for each pair, so I would like to know if the flexing/ride will improve or if I am chasing ghosts...

If you drive on surfaces that flex the suspension at all, then $132/pair is absolutely worth not having a mount rip off somewhere inconvenient.

The only time I've ever used those straight poly bushings was on a 280Z. I don't remember how much travel it had but I would think half or less of even a stock TJ.

 

[Don Bulee]

So when you say lowest tier what ends are on those arms?



I would have to suspect that as well. I ran arms with Clevites on both ends that I cut out of used arms and would still get 4-5 years out of them before they ever stated having issues.

No arguments on that, poly bushings in this application is not a good thing.

right now I have poly-poly ends in both sides of the arms... I'm pretending this next x-mas to improve the adjustable end to a JJ, that was my question, if having one end with a JJ will be a good choice... my idea was to.... instead of getting the Camp series from Core 4x4 which are around 335 the pair (fixed end poly and JJ in the adjustable end), just getting a Cruise series with poly in both ends and to improve it later (I was on a budget) I will spend pretty much the same and the only "con" in my plan is that the camp series tube wall is a little bit more robust (which I considered that cruise series was enough, 3/16" vs 5/16" wall tubing)

If you drive on surfaces that flex the suspension at all, then $132/pair is absolutely worth not having a mount rip off somewhere inconvenient.

The only time I've ever used those straight poly bushings was on a 280Z. I don't remember how much travel it had but I would think half or less of even a stock TJ.

I do wheel my jeep, and I do flex it, not always, not all weekends but I certainly do.... so my question was more in... by having only ONE end with JJ the flex will increase/improve? understanding that the other end will be fixed... I would assume yes, because instead of having an almost zero degree of freedom with the poly bushings in both ends I would have some degree (I think 15, not sure where I read that) of freedom while flexing by having one end of the control arms with a flex joint as the JJ...

 

[freedom_in_4low]

right now I have poly-poly ends in both sides of the arms... I'm pretending this next x-mas to improve the adjustable end to a JJ, that was my question, if having one end with a JJ will be a good choice... my idea was to.... instead of getting the Camp series from Core 4x4 which are around 335 the pair (fixed end poly and JJ in the adjustable end), just getting a Cruise series with poly in both ends and to improve it later (I was on a budget) I will spend pretty much the same and the only "con" in my plan is that the camp series tube wall is a little bit more robust (which I considered that cruise series was enough, 3/16" vs 5/16" wall tubing)


I do wheel my jeep, and I do flex it, not always, not all weekends but I certainly do.... so my question was more in... by having only ONE end with JJ the flex will increase/improve? understanding that the other end will be fixed... I would assume yes, because instead of having an almost zero degree of freedom with the poly bushings in both ends I would have some degree (I think 15, not sure where I read that) of freedom while flexing by having one end of the control arms with a flex joint as the JJ...

Sorry, yeah I follow now.

The thing is that straight poly bushings have two issues and having a JJ at the other end only solves one of them.

Misalignment in the form of the arm twisting around the centerline of the arm tube/body, the flex joint will take it and the poly will do ok. However, misalignment in the arm swinging laterally around the mount, doesn't matter what's in the other end. You're still trying to twist the mount off. The arms want to swing in this motion as the axle follows the arc of the track bar.

 

[Don Bulee]

Sorry, yeah I follow now.

The thing is that straight poly bushings have two issues and having a JJ at the other end only solves one of them.

Misalignment in the form of the arm twisting around the centerline of the arm tube/body, the flex joint will take it and the poly will do ok. However, misalignment in the arm swinging laterally around the mount, doesn't matter what's in the other end. You're still trying to twist the mount off. The arms want to swing in this motion as the axle follows the arc of the track bar.

so.. considering this... I would not be gaining a lot from having a JJ in only one end? since the other end would impede the twisting of the arm? or the gains will be barely noticeable? I understand that the best way is to have both ends with a JJ, but in this case is out of my budget... and I'm not sure if the fixed end can be upgraded to a JJ as well..... I would assume yes, since the crawl series its pretty much the same end but with a JJ.. I already asked them but I havent had any answer