Rock Krawler JT Adventure Pro Upgrade Kit Rear 4 Link - anyone have impressions?

[darkhorse13]

I know this reply is somewhat late, but I had the Rock Krawler Adventure 3.0 Pro installed on my 21 Gladiator Rubicon. The elimination of the rear track bar greatly improves Highway ride/handling, however the rear sags from the weight of a Rebel 1/2 rack, RC steel rear bumper, 23 Zero Armadillo tent, Iceco fridge and misc camping gear. I’m considering running the AEV HC springs. The lift is less than 3 weeks old. The shop that installed ensured me the springs would handle weight. They don’t. Good thing I have Fox hydrolic bump stops.

I still agree with the sentiment that the RK 4 link kit provides the best ride and handling for the JT. If you are referring to the RK 3" springs handling the weight, then unfortunately your shop was misinformed. Most "standard load" springs for the rear of the Gladiator will not handle a constant load of 400lb+ without sagging. You will need to run (at a minimum) a Daystar 3/4" spacer in addition or step up to an HD spring from companies like Clayton/Dobinsons/AEV. These coils will all handle a higher constant load. When unloaded though you will have a firmer ride and likely 1.5-2" of rake. I personally think rake is a good thing but a lot of lift kits shoot for a "level" stance which is why you are seeing the rear sag once weight is added.

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[JTR2021]

I still agree with the sentiment that the RK 4 link kit provides the best ride and handling for the JT. If you are referring to the RK 3" springs handling the weight, then unfortunately your shop was misinformed. Most "standard load" springs for the rear of the Gladiator will not handle a constant load of 400lb+ without sagging. You will need to run (at a minimum) a Daystar 3/4" spacer in addition or step up to an HD spring from companies like Clayton/Dobinsons/AEV. These coils will all handle a higher constant load. When unloaded though you will have a firmer ride and likely 1.5-2" of rake. I personally think rake is a good thing but a lot of lift kits shoot for a "level" stance which is why you are seeing the rear sag once weight is added.

My initial request was to install the Clayton 3.5 but was talked into the RK. I will admit the ride and handling manners are better than stock and I’m sure articulation will be top notch, however I wasn’t building a rock crawler but more of a capable overland rig. Besides the sagging Im concerned the new Fox 3.0 rear shocks are going to bottom out in spite of having new Fox 2.0 hydrolic bump stops. The attached pic isn’t the best but I only have maybe 3.5” of chrome showing. These aren’t cheap shocks either. I’m looking at the Dobinson and the AEV springs now and trying to “guess” which set would work better. Both are rated to around 650-700lbs which should be adequate for my current load. I’d like to avoid spacers as the RK already has a fairly big spacer on the right hand side for the fuel tank weight.

Thanks for the reply.

 

[JTR2021]

I still agree with the sentiment that the RK 4 link kit provides the best ride and handling for the JT. If you are referring to the RK 3" springs handling the weight, then unfortunately your shop was misinformed. Most "standard load" springs for the rear of the Gladiator will not handle a constant load of 400lb+ without sagging. You will need to run (at a minimum) a Daystar 3/4" spacer in addition or step up to an HD spring from companies like Clayton/Dobinsons/AEV. These coils will all handle a higher constant load. When unloaded though you will have a firmer ride and likely 1.5-2" of rake. I personally think rake is a good thing but a lot of lift kits shoot for a "level" stance which is why you are seeing the rear sag once weight is added.

Here’s a better pic

 

[darkhorse13]

Here’s a better pic

In my opinion you need more rear lift to just meet the recommended requirements of the Fox 3.0 IBP rear shocks. Looks like the minimum shaft show should be 4.25" at ride height. This echos the fact that you need another 1" of lift in the rear.

Per Fox's install instructions for part # 883-26-081 (2-3" lift) & 883-26-083 (3.5-4.5" lift)

 

[caryt]

Problem with any Shock manufacturers recommendations is they list 1 shock for a range of lifts. Only way to buy shocks is based on loaded ride height mount to mount length, flex and stuffed measurements and get the correct shock. Best thing to do after that is get them live tuned if that's possible as some shocks are not possible to be valved.

 

[rharr]

I know this reply is somewhat late, but I had the Rock Krawler Adventure 3.0 Pro installed on my 21 Gladiator Rubicon. The elimination of the rear track bar greatly improves Highway ride/handling, however the rear sags from the weight of a Rebel 1/2 rack, RC steel rear bumper, 23 Zero Armadillo tent, Iceco fridge and misc camping gear. I’m considering running the AEV HC springs. The lift is less than 3 weeks old. The shop that installed ensured me the springs would handle weight. They don’t. Good thing I have Fox hydrolic bump stops.

i don't have the X rear but am running the RK adv 3.0. I ended up swaping out the rear 3" springs with RK 4.5" springs to get the rear re leveled when i added my ARE cap. The extra 1.5 gave me the preload i needed. You could be cheap and add some 1.5" spacers to the rear to see if that gets you the preload you need.

you can only fix sag with more preload added to springs or stiffer springs. Both ways get you to about the same place. The added preload helps keep the springs in place on full extension, only caution is to make sure you don't have coil bind on full compression.

 

[JTR2021]

In my opinion you need more rear lift to just meet the recommended requirements of the Fox 3.0 IBP rear shocks. Looks like the minimum shaft show should be 4.25" at ride height. This echos the fact that you need another 1" of lift in the rear.

Per Fox's install instructions for part # 883-26-081 (2-3" lift) & 883-26-083 (3.5-4.5" lift)

Interestingly, I ordered the 0-3” shocks first but was told by the shop I would need 3.5-4” for the rear. My first instinct was correct as I would have the proper travel. Now upon further inspection I noticed there are no bump stop pads installed in the rear lower coil buckets making the Hydrolic bump stops useless. In all fairness these aren’t included with Adventure Pro kit, but should have been brought to my attention. Looks like I’ll be ordering the pads and 3” AEV high capacity springs to remedy this issue.

 

[JTR2021]

i don't have the X rear but am running the RK adv 3.0. I ended up swaping out the rear 3" springs with RK 4.5" springs to get the rear re leveled when i added my ARE cap. The extra 1.5 gave me the preload i needed. You could be cheap and add some 1.5" spacers to the rear to see if that gets you the preload you need.

you can only fix sag with more preload added to springs or stiffer springs. Both ways get you to about the same place. The added preload helps keep the springs in place on full extension, only caution is to make sure you don't have coil bind on full compression.

At this point I’m more worried about my Fox 3.0 shocks bottoming out as I also discovered no bump stop pads were installed in the rear coil buckets. I have Fox 2.0 Hydrolic bump stops but they are worthless without the pads. I measured about 2 and 9/16 of chrome showing on the rear shocks. See pic. Good thing I didn’t decide to wheel this weekend are 2500.00 worth of shocks would have been smoked. I just ordered the RK rear pads and some AEV high Capacity 3” rear coils. This all could have been avoided if I went with my original plan of installing a Clayton 3.5 overland plus lift, but was talked out of it by the shop doing the install. The money pit continues to grow ??

 

[JTR2021]

At this point I’m more worried about my Fox 3.0 shocks bottoming out as I also discovered no bump stop pads were installed in the rear coil buckets. I have Fox 2.0 Hydrolic bump stops but they are worthless without the pads. I measured about 2 and 9/16 of chrome showing on the rear shocks. See pic. Good thing I didn’t decide to wheel this weekend are 2500.00 worth of shocks would have been smoked. I just ordered the RK rear pads and some AEV high Capacity 3” rear coils. This all could have been avoided if I went with my original plan of installing a Clayton 3.5 overland plus lift, but was talked out of it by the shop doing the install. The money pit continues to grow ??

 

[kingsize]

Side Note: RK does recommend bumping the rear springs up 1" for heavier JT's.

• If building an "overland style" or heavily up-fitted build in the back, we recommend upsizing 1” in coil lift height for the rear.

 

[darkhorse13]

Interestingly, I ordered the 0-3” shocks first but was told by the shop I would need 3.5-4” for the rear. My first instinct was correct as I would have the proper travel.

Honestly I wouldn't be upset about the longer travel 3.5-4." shocks. Fox 3.0's are not known for droop and I'd suggest as much as possible. As long as you have the proper ride height, proper bump and proper brake line/ABS line extensions then I'd go for as much shock as you can.

 

[JTR2021]

Honestly I wouldn't be upset about the longer travel 3.5-4." shocks. Fox 3.0's are not known for droop and I'd suggest as much as possible. As long as you have the proper ride height, proper bump and proper brake line/ABS line extensions then I'd go for as much shock as you can.

Agreed, but as it sits now, I have literally about 2.5 inches of down travel before bottoming out. No bump stop protection as well. Good thing I didn’t decide to wheel this weekend.

 

[kingsize]

I have literally about 2.5 inches of down travel before bottoming out

Up travel. You have lots of down travel (aka droop)

 

[JTR2021]

Up travel. You have lots of down travel (aka droop)

Yes you are correct. I was thinking of compression which is virtually non existent.

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