About 5-6 months ago, I swapped out my 2 door 13/55 stock coils with a set of 18/59's from a JKUR. At the same time, I also installed a RC 2.5" bb. I have since added a 1.25" body lift.

I have done all of the necessary geometry correction and the Jeep rides great. The only thing I haven't done is replaced the factory red Rubicon shocks. I installed the shock extensions that came with the RC Series II kit (along with the sway bar links, etc).

The problem I have is figuring out which length of shock to buy. I have read and understand the concept of shock travel, bottoming out, bumpstops, etc. Switching from the 13/55's to the 18/59's gave me about 1 2/3" inch lift up front and a little over an inch in back. Along with the bb, the Jeep is aggressive and level to the ground (no rake, no squat).

The factory Rubicon shocks are as followed:

Front: 14.75" collapsed / 22.75" extended - 8" travel
Rear: 15" collapsed / 23.25" extended - 8.25" travel

I have narrowed down my list of shock replacements and think I'm going to go with the Fox 2.0's.

The 2.5-4" lift shocks (part #'s 980-24-888 rear and 980-24-887 front) measure:

Front: 15.59" collapsed / 25.09" extended - 9.5" travel
Rear: 15.35" collapsed / 24.98" extended - 9.63" travel


Taking into consideration I am using the RC shock extensions with the Rubicon shocks that have less travel, will the Fox shocks even make a difference? Do I need to step up to the 4-6" lift shocks?

 

I don't think there is a perfect answer for what you want. I think you will have to make that decision.

I see it as 2 choices:

1. Longer shocks.

Pros.
More Droop
More potential suspension travel.

Cons.
More bump stops/less upward travel.
May require altering shock location from stock.


2. Shorter shocks but longer than factory.

Pros.
easier install.
allows you to keep your current uptravel.

Cons.
Less total suspension travel.

Here are things to consider when determining length of shocks.
Are you going to go up in tire size? (requiring more bump stops)
Are you going to go with full spring lift in future? (possibly more droop and up travel versus current spring/spacer set up)
Are you going to correct steering with a drag link flip kit? (requiring approx. 3" of bump stop on front passenger side)
Are you willing to alter you shock mounting locations to maximize the benefit of longer shocks?
Have you extended your brake lines for more droop?
What have you done to your drivetrain to prepare for the extra suspension travel?

I think you are on the right track and you need to come up with an answer that will suit your current and future needs.

And for something that is expensive but allows for a lot of up travel and droop; take a look at MetalCloak 6pac shocks @ $400+ each
MetalCloak 6Pak Long Travel Compact Shock Technology (Patent Pending)

Good Luck!
Rob

 

Thanks Rob. Definitely good things to keep in mind for the future.

For now, I'm looking to bridge the gap and remove the shock extensions, while increasing the handling of the Jeep with a firmer ride.

It's hard to take into account the extra spring lift I got from swapping to 18/59's when most shocks take the total progressive coil rating OR the bb lift amount. (In my case, I'm adding the 2.5" and the amount of lift I received from the spring swap). I just want to make sure I don't overstep my bounds by getting a shock too long without making the necessary preparations, but don't want to necessarily spend the cash if the performance from the articulation standpoint will be the same.

 

If you are staying with the 2.5" spacers and JKU springs I would probably go with the shorter Fox shocks that you have listed. I don't think your spring and spacer combo would take advantage of the longer Fox shocks without them either fully compressing or coming unseated.

Now if you are eventually going to switch to a flexible spring only lift, I would probably go with the longer Fox shocks and use bump stops and limit straps to keep everything safe with your current spacer and spring combo. Now to maximize the travel that the longer shocks offer you may have to alter some of your shock mounting locations.

I would also look at Poly, EVO, MetalCloak, (and I am sure there are others) for relocated rear lower shock mounts. By raising the rear lower mount you will gain ground clearance and increase droop at the potential cost of up travel without changing shocks. However Poly also offers a relocated upper shock mount and I would bet that there are probably a couple other companies that do the same and then you may be able to run a longer shock and still have the same up travel.

My last MJ and XJ both had 12" travel shocks with only 4" of lift. I always try to maximize suspension travel but that requires creative shock mounting. I will eventually go with the MetalCloak 6pac shocks.

l'd like to hear what you finally chose and how it works out for you.

Rob

 

I think it's easy to get confused with all the playing factors, but I think finding an optimal length shocks is fairly straight forward when focused on right things. Here is what I did.

The goal here is to make sure you don't lose springs on suspension down travel, and you hit bumpstops before shock is fully compressed.

Now you can go out to your jeep and measure things. Disconnect shocks on the bottom and start lifting your jeep up. See when springs at each axle start becoming loose. Measure the distance between shock mounting bolts/surfaces. That's your maximum extended shock length.

Then lift higher and remove the springs. Start lowering the jeep until it's firmly on the bumpstops. Measure again. That's your maximum collapsed shock length.

Now with this information you can go shopping for shocks. Only then worry about longer brake lines, breather hoses, bump stops to prevent tires from hitting fenders if applicable.

If installing bumpstops you may want to revise max compressed shocks length to higher measure. That may help you find more shocks...