[Pressurized]

The crisis is over... Our Friends at RK have fixed the Mopar (or any other for that matter) spring bow problem found in many lifted JL's. This was most notably seen with the Mopar lift kits.

Front Spring Correction Pad

Here is a repost of my analysis from another thread:

I made a couple of inquiries and it sounds like a couple of the manufacturers are going to be producing their own spring bases for their kits... Probably why some new kits aren't on the market yet.

The bases are a weird design. You would expect them to support the spring equally from the spring tang up to where they not longer contact the spring... This is NOT the case. They only support the spring part way then give out and drop the support way too early. This dropout allows the spring to cant in to the relieved area of the base and thus, causes the spring to angle out on the Jeep. From there the top is brought back in, causing the bow.

Also, the bases are completely different from left to right. The right side spring has a built in 3/8" "spacer". The speculation is that it is to compensate for factory "lean". It also doesn't have nearly as radical of a slope on the spring ramp and the "relief" is less than the drivers side which lessens the bow. I had everyone in the shop, including another local prime time installer that was invited over to partake in the analysis. We all agree it's a failure in the spring base design.

This first picture shows the 2 bases where the spring tang is supposed to sit. This is where you can see the 3/8" height added to the passenger side. You can also see the rate of ramp to support the spring is much higher on the drivers side (left) that is 1 of the causes of the bow.

This next photo shows the ramp height differences better (sorry drivers is now on the right) and it shows the ramp decline (spring relief) that is the major problem causing the bow.

This photo shows the spring just sitting on the base. I put the tang in it's proper position and the spring immediately rolled over the ramp and began to drop in to the relief causing it to lean. You can still see some gap under the spring that goes away with weight on the spring making the lean even worse.

This last photo was me just holding the spring in it's "resting" position in the drivers side base. The lean (bow) is real... That's where the spring wanted to go on it's own.

The humor in this is that the first 2-3 that were done, the stock bases were left in because nobody could see a difference. Including the owners Jeep. Now that we have put them side by side, the softer material in the stock bases does correct a small amount of the problem and why it wasn't showing up as a glaring problem.

For me, knowing that the JL spring bases are hokey to begin with, I'd spend the $30 and put these on a stock JL or one that was just going to use a spacer lift as well. Nicely done by our friends at @Rock Krawler Sus.

 

[Rock Krawler Sus.]

Thanks for the review, we were thrilled with how our JL performed at EJS this year, I can not wait until the Jeep is back home to keep driving it.

Adam C

 

[sined240]

Thanks for the review, we were thrilled with how our JL performed at EJS this year, I can not wait until the Jeep is back home to keep driving it.

Adam C

Is this made with UHMW Stock?

 

[Rock Krawler Sus.]

Is this made with UHMW Stock?

No sir, It is not.

Adam C

 

[sined240]

No sir, It is not.

Adam C

What type of material is it?

 

[Rock Krawler Sus.]

What type of material is it?

We have a ton of competitors asking the same question, We are going to let them do some R&D work before we give that answer away.

Adam C

 

[Pressurized]

I would probably have done an injection molded FRP if I was doing it... but I’m not.

Design wise, it looks just like what I would have done although I can’t see the rest of the ramp...

 

[sined240]

We have a ton of competitors asking the same question, We are going to let them do some R&D work before we give that answer away.

Adam C

lol, don't answer back, but Im going to say, Delrin.

But seriously, which vendor carries it right now? I want to order it soon, as we are expecting my dad's JLUR in the next month or so...

 

[Pressurized]

lol, don't answer back, but Im going to say, Delrin.

But seriously, which vendor carries it right now? I want to order it soon, as we are expecting my dad's JLUR in the next month or so...

I would bet the prototypes would have been machined Delrin... I can't imagine the production part being Delrin, but at this point we need to see them to know.

 

[sined240]

I would bet the prototypes would have been machined Delrin... I can't imagine the production part being Delrin, but at this point we need to see them to know.

After all, seems like most bumpstops are made from Delrin if not Aluminum...

Can be machined/milled and tough...

 

[Rock Krawler Sus.]

But seriously, which vendor carries it right now? I want to order it soon, as we are expecting my dad's JLUR in the next month or so...

We are scheduled to start shipping at the end of the month. I don't believe any vendors have them listed on websites yet, so at the moment the best option is to order directly from us as a presale.

Adam C

 

[JDMcQ]

Any before and after pictures of these correcting the bowing issue?

 

[64Chevy]

I always wondered if these could be made out of UHMW polyethylene. I use this for track car skidpads and it works great.

 

[Rock Krawler Sus.]

Any before and after pictures of these correcting the bowing issue?

Not yet, I have a local customer with a Mopar kit who will be getting some and we will get photos at that time.

Adam C

 

[Pressurized]

Any before and after pictures of these correcting the bowing issue?

Not yet, I have a local customer with a Mopar kit who will be getting some and we will get photos at that time.

Adam C

Here's an after... No need for before, lots of those out there showing the bow.

 

[Rock Krawler Sus.]

Here's an after... No need for before, lots of those out there showing the bow.

Awesome, Looks Great!

Thanks!!