Let's talk bushings! (in track bars anyway)

[chorky]

From a Q&A-
If your finish's primary purpose is to protect your product from wear, weathering, and ultraviolet (UV) exposure, powder coating is likely the best option. While e-coating can provide many of the same benefits, powder coating results in a thicker more durabe finish.

They are actually dipped, rinsed, then cured.
e-coating allows for a much finer control over the final finish thickness and on imperfect surfaces such as areas of welds where there are recesses, pits, holes and so on, it's a better choice as it will get into the irregularities where powder can't due to the electric fields on irregular surfaces.

The problem with powder is the pits and recesses and it can't get "inside" the parts.
And - they are seldom properly prepped. Industrial e-coating usually is preceded by an acid bath and phosphate coating. Powder coating is cheaper, quicker, and as such, is often used where corners are cut.
I have often used a metal prep that leaves a zinc phosphate coating before powder. That will ensure corrosion resistance. So it's not just the difference in the final coat - it's the differences in prep that matter - your powder coated parts are likely just made and coated, little to no prep, no phosphate coating.

This is the PPG processes -



In the first step – pretreatment – metal is cleaned and a phosphate is applied to prepare the surface for application of the e-coat. This process is essential to achieving the performance requirements desired by product end users. PPG Coatings Services analyzes the metals to be processed and chooses the most appropriate chemicals for cleaning and phosphating. In our facilities, the most common pretreatment regimen for steel and iron parts is immersion in a high-quality zinc-phosphate system.
During the next step, coatings are applied to the pretreated metal in an electrocoat bath using precisely calibrated process control equipment. The e-coat bath consists of 80-90% deionized water and 10-20% paint solids. The deionized water acts as a carrier for the paint solids, which are under constant agitation. The solids consist of resin – the backbone of the final paint film, which provides corrosion protection, durability and toughness – and pigments, which contribute color and gloss.
Post-rinsing, which occurs next, enhances the quality of the coating and enables the recovery of excess paint. During the e-coat process, paint is applied to a part using a regulated amount of voltage to achieve the desired film thickness. Once the coating reaches the prescribed thickness, the part “insulates” and the coating process slows down. As the part exits the bath, paint solids that cling to the surface are rinsed off to maintain application efficiency and aesthetics. This residue material, which is called “drag out” or “cream coat,” is returned to the tank, enabling the e-coat process to achieve application efficiency rates above 95%.
After the coated part exits the post-rinse phase, it is placed in a bake oven that cures and cross-links the paint film to maximize its performance properties. The minimum bake time is 20 minutes with a part temperature at 375°F for most e-coat technologies. PPG Coatings Services can also apply a supplemental “low temperature cure” e-coat material depended on volume.


Prep, clean, zinc phosphate, e-coat, rinse, cure.
No double dipping. Why would you?

Too often the quality of the part itself determines the quality of the finish. How many companies really invest in doing powder correctly or doing a prep that includes such cleaning and phosphating? Make part, wipe it off, powder coat it.
The company that spends money will have the better finish.
e-coating is expensive. But even that can be done "crappily" with piss-poor prep and thin coats.
If the e-coated part is gouged or scratched, it will rust - there's steel under there. Phosphating can delay that greatly unless even that is compromised.
Do the phosphate treatment before powder - the powder coating can be scratched or compromised and the steel not immediately rust.
Some do phosphating, e-coating, then powder coating to add UV protection since powder generally has superior UV protection. But again - there's good powder, cheap power, good e-coat, cheap e-coat, good prep, crappy prep.

this is great info to add thanks for taking the time to explain it all. I do understand the idea of powder cost but like you said it is all about prep and that is the concern I have is prep is not good enough for the average parts. I just dont trust that most places do it correctly. The steersmarts arms start with a e-coat and then powder over top of that. It seems like a robust option although I dont know how well powder would adhere to paint.

Shocked that one is needed. Info on bushing types are everywhere as long as you avoid youtube experts.
You could hit the AMC forum from 10 years ago and find all the info you want on bushings, types, uses, pros and cons.

I made this thread because bushing information from various companies was very poor. When several say “dual dendrometer” but then dont specify anything further it makes it impossible to know what you are getting. I wanted to know the specific composition types to assess if bushing from this manufacturer would be harder or softer than bushing from that company. So I was on a mission to find the right bushing option for my application and found it….interesting and figured it would be helpful to others instead of just not knowing what they are paying for

I also found it informative and learned a few new things in the process as well. Willing to bet at least 50% of those with lifts have no clue what types of joints they have and how they compare to other options. It would be cool if there was a source somewhere that sorta talks about it in one spot but I havent found anything like that yet

Because of my experience with track bars on my Power Wagon. I will be going with a track bar with Johnny Joints on both ends. Looking at the Core 4x4 track bar, and their control arms.

First track bar on the PW.
Carli bar Gen 1 with a JJ on the axle, and bushing on the frame. On the frame side bushing. The metal piece that holds the bushing, got egg shaped. Allowing the bushing to move with in it.

Second track bar.
Thuren bar. A JJ on the axle and bushing on the frame. About every 9,000 miles. I had to change the bushing. It was shot.

Third track bar.
Back to a Carli 2 Gen bar with JJ's on both ends. Put 30,000 miles on that bar with no issues. It was still on the PW when I traded it in. As for NVH. Couldn't tell the difference. I also had JJ's on both ends of the control arms and metal bushings in the leaf springs. Couldn't tell the difference in NVH with MT tires.

thats interesting your bushings wore down so fast. What kind of use case was your PW seeing? That could be a contributor. I agree JJ’s are great for articulation but disagree on the NVH. Maybe these newer JJ’s are different but the ones on my TJ are horrid for NVH and have made the ride 50 times worse. Although off road performance is of course great, but I dont take it on difficult trails so its kinda unnecessary. The Jj’s on my TJ are 50,000 miles old. Its neat to hear your experience with them on a bigger and heavier truck!

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[Rusty PW]

thats interesting your bushings wore down so fast. What kind of use case was your PW seeing? That could be a contributor. I agree JJ’s are great for articulation but disagree on the NVH. Maybe these newer JJ’s are different but the ones on my TJ are horrid for NVH and have made the ride 50 times worse. Although off road performance is of course great, but I dont take it on difficult trails so its kinda unnecessary. The Jj’s on my TJ are 50,000 miles old. Its neat to hear your experience with them on a bigger and heavier truck!

My PW has done most of the trails in Moab. Done most of the trails at Rausch Creek. Been to the Badlands a few times. Glamis dunes. It was also my DD. After all the mods and gear that I carried. The PW weight close to 8,000 lbs.

I replaced all of the rubber suspension bushings on my Nismo with spherical bearings and frame mount rubber bushings with solid aluminum bushings. Solid motor mounts and had a solid tranny mount. But it would rattle your teeth. So I have a poly bushing there. The NVH isn't too bad. The exhaust covers most of it up.

 

[dvaders]

Adding my .02... Using a dial indicator, I measured the left and right movement between the axle and frame when turning the wheel left/right on dry concrete drive (22 JT). My Amazon Nexus cheapo track bar allowed for a +/- 0.160 inches for a total play of about 0.320 inches (thus explaining the tendancy to almost death wobble). The TeraFlex track bar was +/- 0.050 inches or 0.100 total. 1/3 of the cheapo. Also, for reference despite an earlier post about bushings, the TF bar has standard vulcanized bushing and not the fancy bushing (to my dismay, but it does have a lifetime warrantly so no worries). Also the OD of the TF bushing is 1.520 inches, width is the standard 1.6 and made for a 9/16 bolt. If anyone is so inclined and has the equipment it would be interesting to see axle play for other setups for comparison. There is never enough data out there and I hate making decisions based on subjective opinions. Hope this helps someone. Also, if you can measure the OD of any track bar bushings and post them it might help me find a replacement for those in the Nexus track bar. It's a nice forged bar, just crap bushings :-(

 

[Chance575]

After 50k miles on my front evo track bar I had to replace its bushings, they both were loose. I switched to a Clayton’s rear bar for the bend in it and it pops every now and then. I just got replacement bushings for it.

long story short check your junk cuz after 50 k miles my bushings were shot from to quality manufactures

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