Suspension Upgrades: Round 4 – Spring relocation perches

Ever since I got the LJ I’ve been plagued with rear suspension issues.  The combination of added length and weight over a base TJ meant the stock rear springs had trouble keeping up.   Add to that a bunch of gear, a trailer, and an oversized fuel tank even the JKS JSpec springs couldn’t keep up.

It’s a lot of weight, but luckily she wears it well.
I do need to do something about that rear end…

I added airbags inside the rear coils last summer in the hopes to mitigate the issue but it was just a temporary solution.  It was also a solution that wasn’t fool proof as I found out when the one airbag developed a small leak.  More research was needed…

Identifying the Problem(s)

If you’re a longtime reader of the ECOA blog, or a fan of the NHT book series then you know I’ve already blown through not one but two sets of rear shocks.  Obviously the problem is more than just the springs.  Another problem I have is that the LJ is equipped with a rear anit-sway bar.  Since I tow that’s something I’m not keen on getting rid of.  At 2″ of lift I’m just on the verge of needing longer links and possibly an upgraded rear bar given the added weight and towing the trailer. So, that leaves me with four problems to address:

  • Rear Springs
  • Rear Shocks
  • Rear Swaybar
  • Airbags
In the garage ready to go under the knife.
With four interconnected problems it’s a bit of a chicken-and-egg issue when it comes to solving them.  I figured before I did anything with the shocks or swaybar, both of which are length based, I’d need to figure out the spring issue first.  Also, while addressing the springs it would be a good time to take care of the airbag – which was thankfully covered under warranty.

Spring Relocation Brackets

In researching solutions for the saggy rear end on the LJ I came across multiple people talking about spring relocation brackets.  TJ’s and LJ’s are known for the quirky rear springs having an arch to them.  Apparently this is bad – very bad – for the spring.  You don’t get full range of motion from the spring or the full spring rate.  That would explain the lack of capacity as well as the rough ride.

By relocating the upper spring mount rearward on the frame it levels out the top of the spring making it parallel to the lower spring perch on the axle.  This not only allows the spring to stand fully upright but also realigns the rear bump-stop to land squarely on the axle like it should.  Most kits I found were weld-on kits.  While not above bribing someone to weld on my rig, I was hoping to find something a little less permanent and something reversible if need be.  Enter TNT Customs.

All the contents of the TNT Customs’ kit.
Well written directions.
A hardware kit.
And of course some nicely powder coated brackets.
The price-point is also nice, making this an affordable upgrade even for a stock Wrangler.

While not a sponsor of ECOA, I have no problem dropping the TNT Customs name.  They’ve been around the Jeep world for a number of years and make many great products.  Once I found their spring relocation brackets I knew they’d do the trick because they are a bolt-on solution.  Some easy enough for me to do myself and also undo myself if need be.

These brackets are beefy.
They need to be given their function.

It’s not all function though.
The outside of the brackets are clean lines with nice curves.

The internal structure is serious.
The attention to detail in the welds, the fitment, and the finish shows they care.

Installation of the Brackets

Here you can clearly see how the upper spring mount is at an angle.

There’s a lot going on with the shocks, springs, air-bags, and the JKS suspension links.

The TNT bracket is in and you can see how it levels out compared to the OEM.
Also, since it’s a bolt-in bracket it can be unbolted if need be.

Here’s the tricky part… getting the springs back into their home.

Here’s the finished product with spring and the new airbag (which was covered under warranty).

Was it worth it?

So, was it really worth the time, money, and effort?  Well to be honest I’ve only gone about 40 miles so far… but I think it was.  The rear end feels a lot more stable.  The air bags work again.  All in all it feels much better.  As you can see below via the before and after photos I think the LJ picked up just over an inch of lift in the rear.
Hard to see, but the rear is visibly sitting higher.
Not enough to give it too much rake, but it should sit level with a full-tank.

A better comparison.  I tried to line it up as best I can.

What’s next?

Now that I have the spring issue taken care of, I’m going to measure for new rear shocks.  I’m seriously considering jumping all the way to a remote reservoir shock.  There are a couple of reasons for this, but I’ll save those for that install writeup.  I’ll also measure for longer rear sway-bar links, although I’m also going to look into something like an anti-rock for the rear given they are adjustable (to a certain extent).  Lastly, I need to finish plumbing the airbags so they are tied in with the onboard air system.  AirLift has some pretty slick parts but no off-the-shelf DIY “kit.”  I’ll have to piecemeal it  together, but that’s the fun part.
So, stay tuned for more upgrades and once things are dialed in it will be time to hit some trails again!

Also, a huge shout-out to perennial ECOA & NHT supporter Jim for use of his garage, lift, tools, time, and talent yet again.  Made this install go nice and smooth and his experience with airbags was a major plus.