Budget control arm idea

[astjp2]

here is the rule of thumb on press fit bearings, the synergy and the clayton lowers have a .007 press fit. So does the Clevite from what I have read, but the clevite is a stepped bushing. I will try to get a few and see how they press in. I am also including the clayton rod end drawing.

 

[Blackjack]

Ddb do not fit stock arms or any aftermarket arms including the older style synergy arms.

You will also need to purchase synergy cold cut rings to weld on and then press in the bushings.

Synergy also has 1.25" 1" and .75" left hand thread housings. Synergy adjustables are adjustable without removing one end or messing with jam nuts.

The dual durometer bushings are far superior to duroflex joints and outlast pretty much everything we can buy. They are self centering high misalignment joints. View attachment 75283

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DDB do work in some aftermarket lowers that used a clevite like Rubicon Express. The DDB even press into the RE superflex joint end rings as well.

I just don't understand why one would want to go thru all the trouble of trying to figure out if Synergy joints will fit X or Y arms when the company clearly doesn't have any interest in producing TJ arms/joints anymore. They are focusing on what makes them $$$, and that is JK, JL products. Now, if you are doing it for the challenge of it, then carry on. I have over 35,000 miles on Duroflex joints with no sign of wear whatsoever, so if someone has any real data that Synergy joints are better than X or Y joints I'd like to see it.

I know that Synergy no longer offers lift kits but was not aware they stopped producing TJ arms.

I went through the trouble as I had what was basically a mix of RE super ride and super flex arms and was tired of both the clevites and the super flex joints. So for me I only had to buy some bushings and a couple of end rings for the upper arms. Time will tell how durable these are in the climate I am in but it is worth a try.

 

[bobthetj03]

I do see that they still make the arms. For how long, who knows? They do not make a front axle upper kit, so you're stuck with Clevites there I guess. The joint design is intriguing for sure.

 

[Blackjack]

I do see that they still make the arms. For how long, who knows? They do not make a front axle upper kit, so you're stuck with Clevites there I guess. The joint design is intriguing for sure.

You can run JJs with the DDB so that it what I am going to do.

 

[bobthetj03]

You can run JJs with the DDB so that it what I am going to do.

It seems like we've had this conversation before, but do you think the DDB is up to the task of returning the JJ back to center, cause that is what the DDB is inherently designed to do. the JJ doesn't care where it rests, but the DDB might.

 

[mobile chernobyl]

It seems like we've had this conversation before, but do you think the DDB is up to the task of returning the JJ back to center, cause that is what the DDB is inherently designed to do. the JJ doesn't care where it rests, but the DDB might.

I would imagine that in it's dynamic state (i.e. suspension moving) the friction of the JJ can be overcome by the spring force of the DDB. In a static fashion, i.e. on a 'test bench' or trying to move by hand, it would appear to be difficult - but not indicative of the real world forces at play. Bushing style joints like the JJ have high static coefficients of friction relative to their low frequency dynamic coefficients of friction.

In the mountain biking suspension world (specifically rear downhill race bike suspension) we have dealt with the challenges of overcoming this static to dynamic friction threshold with bushings - once in dynamic motion (i.e. actually riding the bike) you usually don't notice it at all. This is why so many bikes use bearings in the rear suspension because of the low (almost non-existent) threshold to go from static to dynamic motion.

 

[Blackjack]

It seems like we've had this conversation before, but do you think the DDB is up to the task of returning the JJ back to center, cause that is what the DDB is inherently designed to do. the JJ doesn't care where it rests, but the DDB might.

Synergy during their transition to the DDB ran JJs on the adjustable end of several of their arms.

 

[bobthetj03]

I'm not too concerned about the dynamic motion. A joint is going to move and articulate as it is designed. It's when the jeep is parked that concerns me, and I'm probably way over thinking this. As an example, a lower arm with jj's at both ends often times will sit articulated at static. JJ don't care. It don't need to return to center. However, you put a jj at one end, and a joint that is designed to return to center at the other end, then the return to center joint will constantly be under load trying to center the jj at the other end, and jj's take a little effort to move. So, your jeep is sitting in the garage, minding its own business, as this constant battle of self centering supremacy rages on underneath. Ok, I exaggerate a little, but you get my jist.

 

[jjvw]

An interesting anecdotal story about overcoming static friction, recently I was helping one of our big long distance moving trucks with a job on a snowy mountain road. The east coast driver slipped off the edge of the road on a tight turn and got stuck. Could of and should of done several things to avoid it, but it happened. Even after we put the tire chains on the rear drive wheels, there was no traction in the snow and ice to drive out.

But I noticed while we were trying to maneuver, that every time the driver turned the steering wheel, the front end would slide sideways down hill an inch or two. That was the motion we needed to turn the truck out of the ditch. I told the driver to keep turning the steering back and forth, each time breaking traction and putting the truck into a very short controlled slide. Over the course of 20 minutes and inch by inch, we swung the front end of a loaded 28,000lb truck over about 25 feet to make the turn, point down hill and be able to drive back up onto the road to freedom. The driver's arms were very sore.

I believe that as the JJ is rotating with the suspension travel, the DDB will be able to return itself to center.

 

[TJustin]

I have the Rokmen double adjustable rear uppers, and the front double adjustable Currie arms on my TJ. While I can vouch for the ease of adjustability for adjustability of pinion angle or caster angle, if they were much more than what I paid at the time compared to the single adjustable counterparts, I likely would have gone single adjustable.

I will say, that I was much more encouraged to dial in angles with the double adjustable arms knowing it was a quick procedure. Like Jerry and others have mentioned, once you have the angles dialed in, no need to move them unless you undergo suspension or drivetrain changes.

Regarding pricing, I think you'd be better off checking classifieds, eBay, etc for a used set of quality arms with JJ's or other flex joint in them if pricing is a concern. Rebuild kits are cheap (if needed) and are simple to do. I've used the Johnny Joint flavor for almost a decade now, grease them periodically, and have not had to rebuild one thus far. knock on wood

 

[glwood]

I do see that they still make the arms. For how long, who knows? They do not make a front axle upper kit, so you're stuck with Clevites there I guess. The joint design is intriguing for sure.

Does MC have a replacement front axle upper kit?

 

[jjvw]

Does MC have a replacement front axle upper kit?

Yes. Finally.

 

[k-huevo]

It seems like we've had this conversation before, but do you think the DDB is up to the task of returning the JJ back to center, cause that is what the DDB is inherently designed to do. the JJ doesn't care where it rests, but the DDB might.

Yes, this has been discussed, and you were involved. The answer is a JJ always returns to center when paired with a DDB on the other end. The JJ housing will move around the ball, so in essence it remains centered/parallel/horizontal through the majority of axle movement.

If the JJ is too difficult to move with only hand force, try better lube. I use Chevron EP-2 grease with Black Moly. Someone else recommended Red Line CV-2 with red Moly.

 

[Blackjack]

I'm not too concerned about the dynamic motion. A joint is going to move and articulate as it is designed. It's when the jeep is parked that concerns me, and I'm probably way over thinking this. As an example, a lower arm with jj's at both ends often times will sit articulated at static. JJ don't care. It don't need to return to center. However, you put a jj at one end, and a joint that is designed to return to center at the other end, then the return to center joint will constantly be under load trying to center the jj at the other end, and jj's take a little effort to move. So, your jeep is sitting in the garage, minding its own business, as this constant battle of self centering supremacy rages on underneath. Ok, I exaggerate a little, but you get my jist.

For giggles I just went out in the shop and played with small JJ and DDB. I can easily manipulate the JJ with a small screwdriver even with it a balmy 20 degrees. The DDB on the other hand I could barely budge with a foot long bar so I do not think there is anything to worry about.

 

[bobthetj03]

It's just been fun discussing the differences. Am I worried? Lol!

 

[Blackjack]

It's just been fun discussing the differences. Am I worried? Lol!

And that is a good thing for both us as users and the manufactures if they are listening. It would be fun to get my hands on a Duroflex bushing to compare the difference in stiffness versus a DDB and a clevite.

 

[jjvw]

Somewhere in my build thread I talk about comparing a 2" JJ and a 2" DF bushing. I recall being able to move the JJ by hand far more easily than the DF.

 

[astjp2]

And that is a good thing for both us as users and the manufactures if they are listening. It would be fun to get my hands on a Duroflex bushing to compare the difference in stiffness versus a DDB and a clevite.

Dan, get a Girro joint also and put that into the mix...

 

[bobthetj03]

And that is a good thing for both us as users and the manufactures if they are listening. It would be fun to get my hands on a Duroflex bushing to compare the difference in stiffness versus a DDB and a clevite.

I'll send you one. I have a used lower. It's in great shape. It's just the bushing though. I don't have a spare barrel.

 

[Blackjack]

Dan, get a Girro joint also and put that into the mix...

I am pretty sure that they are the same bushing. It would appear they are manufactured by Red Ranger https://www.redrangerusa.com/giiro/

I'll send you one. I have a used lower. It's in great shape. It's just the bushing though. I don't have a spare barrel.

That would be great. I was thinking last night about a way to redneck a means of measuring the force necessary to get them to full misalignment. I am sure I can create a barrel that would work for that.