Does control arm bushing composition affect ride quality or NVH?

I put in the jk axle bushings, the only issue I had was finding bolts and the stamped mount did not want to hold the bushing, so I JB welded it. A trip the the junk yard got me some bolts from a dodge truck upper control arms.
 
I don't recall what he says about rod ends/heim joints, but most of the common control arm joints/bushings have an isolation material as part of their design.

Similar to the differences between spring rates, the assertion is that the differences between joints/bushings are not perceivable. I'll concede just a tiny bit and suggest that the differences are minor to the point of insignificance.

Something else he often brings up is that unless you are only making single changes, how do you know what is contributing to whatever change your are perceiving.

If you really want to isolate the problem only change one variable at a time. This is a practice I use in custom reloading for long range accuracy as well as pinpointing many other problems. Change more than one variable at a time and you will forever chase your own tail.
 
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I put in the jk axle bushings, the only issue I had was finding bolts and the stamped mount did not want to hold the bushing, so I JB welded it. A trip the the junk yard got me some bolts from a dodge truck upper control arms.

Thats what I thought you did. But after talking with the Synergy tech I thought maybe I was misunderstanding everyone. I was really confused because it was a Synergy tech that told me to use the JK bushings when I called about it several months ago. Sounds like it was just a matter of the tech I talked to this time not knowing anything.

I've been tempted to try the JK kit with the solid mounting plate (#8012-12) . But since its not the right height for the TJ, I'm concerned that by the time I have the plate cut to fit and pay someone to weld it in, I'll wish I just went with the Currie kit.
 
If you really want to isolate the problem only change one variable at a time. This is a practice I use in custom reloading for long range accuracy as well as pinpointing many other problems. Change more than one variable at a time and you will forever chase your own tail.
I agree on concept, but not many people want to take their vehicle apart many times to solve a problem that can be done on the first go around...
 
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Thats what I thought you did. But after talking with the Synergy tech I thought maybe I was misunderstanding everyone. I was really confused because it was a Synergy tech that told me to use the JK bushings when I called about it several months ago. Sounds like it was just a matter of the tech I talked to this time not knowing anything.

I've been tempted to try the JK kit with the solid mounting plate (#8012-12) . But since its not the right height for the TJ, I'm concerned that by the time I have the plate cut to fit and pay someone to weld it in, I'll wish I just went with the Currie kit.
Just use the JB weld, its a 10 minute job unless you beat on your stuff, then if it comes loose, fix it then. I am interested in how the spring rate change affected the ride...with the same shocks. I may want to swap mine out later, once I mess with the driveshaft vibes and death wobble problems.
 
Just use the JB weld, its a 10 minute job unless you beat on your stuff, then if it comes loose, fix it then. I am interested in how the spring rate change affected the ride...with the same shocks. I may want to swap mine out later, once I mess with the driveshaft vibes and death wobble problems.

Unfortunately, I changed priority and decided to take care of my control arms before I do the spring change. I'm still going to do the spring change but it will be later this summer or fall now. Sorry to keep you waiting.
 
Hey, at least you will be able to give good info on your impression of the change.

Yeah, I plan to be methodical so I can check things with that vibration sensor phone app.

I am going to change out my control arms and check things, then my trackbar, then the springs. Today I just ordered the Rancho D2 trackbar to go with the control arms. I'm undecided if I will do the trackbar first or the control arms.
 
I just got the Synergy DDB bushings about an hour ago for the front upper axle. Here is a picture of the Synergy next to the Rancho D2 control arms. Obviuosly they are different bushing locations so some differences in design. The DDB also has a larger bolt hole because it is for a JK. I will just drill out my control arm yoke to fit the bigger bolt.

The material feels pretty similar to the touch and the sleeve also looks pretty similar in material. I don't really have a way to test the resistance to see how they feel in that respect. But just looking at them and feeling the materials, they feel like they are likely the same thing. So they could be the same mfg, but its still really hard to say.

One big difference that I noticed was the bolt sleeve inside Rancho D2 bushing sleeve fit really tight. They Synergy DDB bolt sleeve pops in and out easily with a little pressure from my thumb. Its interstesting that it kind of snaps in and out, but I don't see any kind of grove that it is snapping into.

Who was it again that had the Giiro joint? Did that sleeve kind of snap in and out or did it slide really easy? It makes me wonder if the Giiro joint and Synergy are indeed the same bushing. Along with the Rancho D2. They seem to have some similar characteristices. It may be just be a quality control issue that some slide in and out where others fit tight.

Anyway, I was disappointed that they are not a tight sleeve. This makes me question if I will have wear issues down the road and leaves me wondering if maybe I should have just gone with a JJ but we'll see. At this point it really depends on how durable that Teflon liner is.

Synergy DDB vs Rancho D2.jpg
 
I just got the Synergy DDB bushings about an hour ago for the front upper axle. Here is a picture of the Synergy next to the Rancho D2 control arms. Obviuosly they are different bushing locations so some differences in design. The DDB also has a larger bolt hole because it is for a JK. I will just drill out my control arm yoke to fit the bigger bolt.

The material feels pretty similar to the touch and the sleeve also looks pretty similar in material. I don't really have a way to test the resistance to see how they feel in that respect. But just looking at them and feeling the materials, they feel like they are likely the same thing. So they could be the same mfg, but its still really hard to say.

One big difference that I noticed was the bolt sleeve inside Rancho D2 bushing sleeve fit really tight. They Synergy DDB bolt sleeve pops in and out easily with a little pressure from my thumb. Its interstesting that it kind of snaps in and out, but I don't see any kind of grove that it is snapping into.

Who was it again that had the Giiro joint? Did that sleeve kind of snap in and out or did it slide really easy? It makes me wonder if the Giiro joint and Synergy are indeed the same bushing. Along with the Rancho D2. They seem to have some similar characteristices. It may be just be a quality control issue that some slide in and out where others fit tight.

Anyway, I was disappointed that they are not a tight sleeve. This makes me question if I will have wear issues down the road and leaves me wondering if maybe I should have just gone with a JJ but we'll see. At this point it really depends on how durable that Teflon liner is.

View attachment 103282

Some advice from a fellow DDB convert ... throw them in and enjoy the ride !!! They’re great, they tighten up the Jeep. I am confidant they will do so until they don’t, I won’t stress about their durability until they fail which I hope is a long time from now. Until then enjoy the ride ...

BTW: I noticed that some bushings are tight and some are lose (like you said). I wouldn’t worry too much about contamination as I assume the “soft” bushing material makes a decent seal... again, we will soon see ...
 
Some advice from a fellow DDB convert ... throw them in and enjoy the ride !!! They’re great, they tighten up the Jeep. I am confidant they will do so until they don’t, I won’t stress about their durability until they fail which I hope is a long time from now. Until then enjoy the ride ...

BTW: I noticed that some bushings are tight and some are lose (like you said). I wouldn’t worry too much about contamination as I assume the “soft” bushing material makes a decent seal... again, we will soon see ...


PS: those axle bushings are a BEAR! I drilled out the bushings with drill bits (went larger and larger) until I popped the sleeve out, then put a slice with my sawzall and they came out easily. When pressing in, you can go to town on the cast iron side, but the passenger side mount will need a little care when installing. In hindsight, I should of made a sleeve out of PVC, pressed in the bushing fully then cut off the PVC sleeve... all this to keep from deforming the passenger side axle bushing mount.
 
PS: those axle bushings are a BEAR!

My plan is to let a local shop do those for me. Hopefully they have a clue and can do them properly and not just screw them up and charge me $200 for doing so. But its a shop I have used before and trust. So I expect they will figure it out.

After I get the axle bushings done, I will do the rest of my Rancho D2 arms in the following week. I'm looking forward to see how things drive after this.
 
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In my personal opinion, bushings, no matter what they are made of, don't help flex or articulation in a meaningful or significant amount. If you want a joint to help give more usable flex go with a quality flex joint like a Johnny Joint.

I think we learned that even a solid/rigid bushing won’t hinder flex/articulation, the control mounts would rip off if forced to by the axle (remember the old school polyurethane control arms).

What is nice is that the bushing CAN handle some misalignment... and hopefully keep doing so for a long time without failing or causing too much stress to the frame/axle mounts.