I'm not sure I understand much about ball joints and what exact Purpose they serve. So what would b the diff between getting the moog k8008 opposed to the btf upper arms. What r they price differences between the 2?
Also def not familiar withe these limit straps u speak Of?
If you look at your front suspension you'll notice a large silvery colored metal piece coming up vertically between your front wheel and front spring. That's called a spindle. Attached to that is a triangle shaped metal arm, called an upper control arm. The rubber coated hinge that connects the upper control arm to the spindle is called a ball joint.
the OEM ball joints are designed to spend most of their time at limited angles. When you put on a BTF lift, those ball joints now spend all their time at an increased angle, which causes them to wear faster. If you offroad it really hard with the BTF lift, you have a greater chance of separating the ball joint from the spindle or control arm.
The Moog brand ball joints that were mentioned can be had at any major auto parts store. They seem to be tougher than OEM. Besides, at this point you might as well replace your OEM ball joints anyway. The pair of them will run about 50-60 bucks total if I remember correctly. There's a thread in the stock 2002-2005 explorer forum at the top that talks about how to swap them out.
The BTF Uniball upper control arms are a complete aftermarket replacement for your OEM upper control arms. They use a very strong joint between the upper control arm and the spindle, it's called a uniball and has a greater range of motion than a ball joint and is a lot stronger. When it does eventually wear out it costs about a little bit more than a ball joint but it should be easier to switch it out.
The BTF uniball upper control arms are also slightly longer than the stock control arms to help correct some of the bad suspension geometry that you get at full suspension droop with the BTF spacers. They run about $570 a pair.
Limit straps are pretty simple. They attach between the frame and suspension and prevent the suspension from overextending and causing problems when you are running a BTF lift. They don't seem to be very expensive, the only thing is you have to get some mounting tabs welded to your frame and suspension.
Bottom line is this: How do you plan on using your truck? if the lift is just for looks and gets driven on the street/snow/beach, you'll be fine with just the moog ball joints. If you take it on trails where the suspension gets flexed out and the truck is bouncing over logs and rocks then you're going to want the BTF upper control arms. You might also be fine if you just used moog ball joints and limit straps.