So I measured a 1/2" sag on the passenger rear. I have the RK coil correction wedges and RK 2.5 springs. Lift was installed professionally 1 1/2 years ago. The spring seems to be bowing forward. Any ideas?

 

pretty normal. i have the same. wedges and all.

 

What lift you running? Do you have the control arms as well, ie rear end moved aft 1"? If so, a wise investment is to rotate the perches and easiest way is with the JKS kit. Looks to me like they're bowing aft as expected.

I've also found the new triple rate springs are VERY soft and I even went back to their older linear springs for that reason. Not to mention, a full tank will have some effect.

 

The lift is RK 2.5 max travel with LCAs. I'm at about 3/4 of a tank so might be a factor....

I believe these are the old RK linear coils due to the time frame I got the lift so I'm not sure why they seem so compressed. Guess these things are to be expected when you start modifying the geometry of a vehicle.

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Well, looking at them again, you may be right about linears. Some things can be expected but I wouldn't like it either. Mine sags 1/2" with full tank which is hardly perceptible. I only know it because I've measured the rocker panel. (I have the 3.5 max travel) I would look at 1 of 2 options: cut the perches and reweld or install the JKS kit which allows you some room to play with perch angles, and/or get new springs. If your springs are contacting the trackbar, you need to rotate the perches anyway. The wedges did little for me.

I would also try running the tank empty and then swap springs to see if the sag follows the spring. If so, you know you have a weak spring but I've not seen that often.

 

To add some info to that...
I put a scale under each tire of my stock JK, with half a tank of gas, no occupants.
The weights side to side were darn close to equal. Adding 10 gallons to fill the tank will add about 60 pounds to the right side, with some of that weight close to the center line, and some of it being shared by the front spring.

 

If the springs sag under let's say 100 pound difference between a full tank and empty, how bad is it going to be say with a load of camping gear. Hell even a cooler, chairs and 4 people headed to the beach. Going to sag what 2-3 inches based on 1/2" for 60 pounds. Sounds a little too soft. Main reason I switched out the rk rear springs.

 

What did you switch them out with? I'm pleased with my front coils, plenty of lift from the 2.5 coils up front.

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There are quite a few things that might cause the vehicle to lean slightly. Here is what we would recommend checking:

First make sure that the front and rear axles are centered under the vehicle. If they are not centered it can cause the vehicle to lean. Unfortunately your rear kit did not come with an adjustable trackbar so you will not be able to adjust. However, if it is off, that would be the cause.

Make sure your rear axle's pinion angle is two degrees shallow of dead on. If the pinion is not correct the coils will bend more excessively and ultimately lose rate (cause squatting).

When you do this also disconnect your swaybars. If there is tension on a swaybar link it can cause the vehicle lean. Also, by disconnect the rear swaybar we can tell if the factory swaybar is bent. We have seen a few rear swaybar bend after off road use and effectively cause the vehicle to lean afterwards because it is loading one side.

We have tested these coils with and without a considerable amount of weight in the rear and can tell you that it will perform far greater than a linear coil. However, changes in weight are noticeable before hitting that third rate but that is the result of having a driving rate range designed for comfort. Hopefully that makes sense.

RK