First off forgive me - I am by no means a car guy. I do however very much love my Jeep.... I have a '10 4dr Rubi with a 3" TF, & Duratrac 315.70.17
My issues are.... it feels "loose" at hwy speeds, another concern is while towing a 12'X6' utility trailer with 2 dirtbikes and a 4-wheeler (aprox 1900 lbs), it feels very under powered??? tow rating is listed at 3500 lbs???????

 

As for it being underpowered unfortunately that's just how the 3.8l mini van engine is. Only options really is to regear which will get you best results or a superchip flashpaq.

By loose do you mean it feel kinda "flighty"? If so , with your lift kit are you using the stock Trackbar, stock Trackbar with a bracket or an adjustable Trackbar? I had the same issue with my RC 3.5" lift and an adjustable Trackbar really helped with the issue.

 

What gear ratio?

What's the caster set at?

 

I developed a shimmy coming from the front end. When I cycled through the steering, I could see play from the drag link connection. The shimmy was worse when I'd go over offset bumps in the road. You may not know cars real well, but you can still get under your Jeep and start looking around at things. Have a friend help you out. Start from the Pitman arm and just work your way down. Grab onto the LCA's and UCA's, make sure they're torqued down. Loose track bars are notorious for creating issues. No better way to get to know your Jeep. It won't take long to look at all the components. You just may see something that doesn't look right, and then you can help your mechanic to diagnose the issue if you're not comfortable doing it yourself.

 

i had a very uncomfortable "flighty" feel after installing a 2.5" TF coil lift and adjustable track bar. it got a little better after 35's, but it still sucked. i finally fixed it with front lower adjustable control arms. i settled on 8• positive caster and can go over 65 now

 

8 ? :eek:

How's your pinion angle

 

Your engine needs to be running at or above about 3000 rpm to have a meaningful enough amount of horsepower and torque to pull heavy at highway speeds. On flat ground at slower speeds, you need to be over at least 2500 rpm.

So, you need to either downshift or regear your rig to run at those engine rpm levels.

"Loose" at highway speeds...if that means that your rig "wanders," you may need an alignment because you have too much or too little toe-in or too little caster. If you are running more than 35 psi in those tires, that could contribute to the "wandering" problem.

Did your 3" Teraflex kit include front lower adjustable control arms and an front adjustable trackbar?

 

it's not bad actually. when i first installed the arms at the length specified for my lift, i was at 13•, the angle was horrible. i backed it off to 8,at least that's what the angle finder says. drives great now. i may still tweak it, but for now I'm happy

 

You are probably in the 6 range. From what I gather only a alignment can tell you the real caster angle.