I’ve got some Core 4x4 stuff, these are things I noticed…

The Core 4x4 Camp series lower control arms. They are BEEFY. They are compatible with factory hardware although I upgraded everything to grade 10.9 bolts. These control arms have a johnny joint and a polyurethane bushing. I was surprised at how thin the powder coating was. After simply laying them on a concrete garage floor they were noticeably scratched. I’m not concerned about this – they’ll get plenty of scratches soon enough.

The Core 4x4 Camp series upper control arms are the exact same thing as their crawl series and at the same price. The upper control arms are pretty beefy too. I found the forged adjustable johnny joint on these uppers to have a larger than stock I.D.. The stock bolt was 10mm. The eyelet on the johnny joint measured .438”. A 7/16” bolt fit perfectly. But the frame side bracket had to be drilled out to match. I could not find anywhere (and it may be there, I’m just not able to find it) any mention that factory hardware would not work. I wasn’t unhappy about this as larger hardware is an upgrade but I wish I would’ve known before hand so I could have been prepared with the proper size bolts instead of making a trip to the hardware store. The grease fittings that come on the johnny joint (frame side) are plain straight fittings. On the XJs mounting location you cannot get a grease gun on them. 90 degree fitting don’t work because they point at the jam nut. They have to be swapped out to a 45 degree fitting and even then they are hard to get at with flexing your axle upward. I found that its easy to do with a needle adapter that you usually use on u-joints.

The Core 4x4 Crawl series track bar and bracket. The bracket has 4 holes in it so you can pick the best drop for your lift and steering set up. It mounts using factory hardware. Core 4x4 does not offer a bracket brace solution. The XJ uniframe needs all the help it can get. Just an FYI, the Stinky Fab Racing track bar bracket brace fits the Core 4x4 bracket almost perfectly. The bar is solid and thick with johnny joints on both ends. The bolt kit they sent was only half correct. They use a ˝” bolt for the frame side and they sent a 10mm bolt for the axle side but the fixed johnny joint had a .482” I.D. … so after another trip to the hardware store, a 12mm bolt fit perfectly. Just had to drill out the holes on the axle mount… I almost feel like I made a mistake ordering the crawl version. Johnny joints are great and rebuildable and all that… but some bushing flex can keep things from breaking. Johnny joints do not give – they just rotate and pivot. Its very solid. If you have upgraded your axle side mounting bracket to something thicker than stock, this might not be an issue. But I am afraid that without a little cushion, it may try to wallow out the hole on the axle side. I’m going to keep an eye on this and if I get any play in the axle bracket hole I’ll probably go with a Trail Forged track bar that uses their “better bushing” on the axle side and a Heim joint on the frame side.

Comments or advice welcome!

 

Solid feedback on the Core 4x4 stuff good catch on the hardware sizing and grease fitting issues. Johnny joints are stout but you’re right, no flex can stress weaker mounts. Keep an eye on that axle bracket. If it starts wallowing out, swapping to a Trail Forged bar with a bushing might save headaches later. Otherwise, beefy setup just needs a few tweaks.

 

Yep it happened. The Core 4x4 crawl series track bar wallowed out the axle side bracket after about 750 miles on road and maybe 25 miles off road. Having johnny joints on both sides is not a good idea unless you upgrade your mounting bracket on the axle.

I'm talking with a local company, Trail Forged, about making a new track bar. The Trail Forged track bar comes with their "better" bushing on the axle side and a large heim joint, they use 9/16" hardware on each end.. They're checking to see if they can make one with a Johnny joint instead of the heim joint. I like the greasable and rebuildable aspect of the jj.

https://trailforged.com/product/front-track-bar-hd-adjustable/

Now that my 12mm axle side hole has wallowed out I will be buying a replacement probably before the day is over.

So kids, upgrade your mounts before you go with johnny joints on both ends of anything. If my axle was a high pinion I would be investing more into it but alas, it's a low pinion and is not worth the effort.

 

JJs at both ends may transmit a bit more impact loading, but there should be no articulation issues with JJs at both ends. Interesting that it wallowed with a 12 mm (class 10.9?) bolt. Torqued to 100 ft-lbs? If the hole is not wallowed too much, there are conversions to a 9/16" grade 8 bolt that can be torqued to 150 ft-lbs.

 

Yep 12mm, class 10.9, torqued actually to 105 ft lbs. Everything was tight and fine until I did a short trail, very easy trail called Bobblets Gap. I wasn't going fast but it was very bumpy, like really dang bumpy. My Wife is pregnant with another child (due in a few weeks) and had a 1-1/2 year old in the back too, so I can't be yee-haw'n my way up the mountain. I do not blame Core 4x4 at all. It is good stuff. But for jj on each end I would highly recommend heavier than stock bracketry. So it was my bad.

Good news is I caught it before ir got too bad. I can salvage the hole. Trail Forged uses 9/16 hardware and there will be a bushing at the axle end. They were able to swap out the heim for a Johnny joint on the frame side. And I should have it Wednesday. I couldn't be happier with the customer service. I'm running the better bushing from them on my axle side upper control arms. It's supposed to be better on every way compared to poly or rubber. But I'm getting off track here...

With 9/16" hardware and the bushing I really think everything will be fine going forward. After install I'll follow up with a post about it.

 

In case you are interested, the Better Bushing is sold by Clayton Offroad as a Giiro bushing and by Synergy as their dual durometer bushing. I bought a Synergy DDB bushing to analyze when I was building my front suspension. And Metal Cloak also makes two compromise bushings that are different from the Giiro/DDB.

 

I am always interested. Thanks. Im not a rock crawler or desert crosser, or other more advanced off road stuff doer. But I love going up and over my local blue ridge mountains. I hope that the better bushing will meet my needs and have a good life span.

 

I got the Trail Forged track bar in and installed. Very well made. I had them install a johnny joint instead of the Heim joint on the frame side. They were super easy to work with, and shipped out the bar the next day. It feels great! Going to the 9/16 bolt on the axle side allowed me to clean up the wallowed hole back into a perfect circle. I'm good to go again.