resharp001

So I’m just catching up with this thread. Here is the best picture to reference.



My aftermarket drive shaft re-uses the factory pinion flange, so I like to use that by placing the angle finder on top of the flange. Consider that your factory axle has 6 degree of caster built in to it. If the pinion angle is zero, that means you have 6 degree of caster. For every degree that your pinion is shifted upwards, you’re subtracting the same amount from that caster. If you set that angle finder on the pinion flange and it reads 2 degrees for example, then you have 4 degree of caster.

If I’m reading your pinion measurement correctly, I’m thinking that you’ve put an angle finder on the face of the pinion flange, and that is how you’re getting 93 degrees, or that your pinion is facing up 3 degrees. If that is indeed the case, that would mean that you’re generally running 3 degrees of caster (6 degrees – the 3 degrees the pinion is rotated up). Does that make sense? All of that of course is dependent on you taking a measurement on flat ground (accounting for any slope in garage slab or such) and that you’ve placed the angle finder in a reliable place to get an accurate reading.

Now, this isn't going to be as exact as going to an alignment shop, but it's going to be generally close. For those trying to figure this out, think about the fact that as you lift the jeep (assuming you don't correct the geometry), the C's on your axle are coming closer and closer to being perpendicular with the ground. As that happens you're going to have less than ideal experience due to running too little caster.

Neeland

Actually that makes complete sense and I can't tell you how many things I've read including the article with the picture you add. When I was trying to figure it out I want accounting for the 6* in the factory knuckles. The surface was about as flat as I'm going to get and it was done with an angle finder on my phone. I don't need it to be dead correct I just need a really good idea. My rubicon express brackets give me an option for the middle whole at 7-8" from the measuring points and bottom hole for 8-9". I'm dead at 8" so I wanted to start in the middle hole and check the caster and if I could get away with going to the bottom hole then adjust to that.

BigRich26

Thank you, I really appreciate your advice. I'm going go ahead and buy the front control arms (probably not MC, as much as I want them they're probably overkill for my needs) and the drag link and tb bracket.

resharp001

I think sometimes it's easy to overthink this stuff even though as you see, it's not that complicated. Keep in mind that although there is 6 degree of caster built in to the axle, from the factory the JK comes with 4 degree of caster (the pinion is angled up by 2 degrees).

resharp001

I run a mix and match of different brands on my jeep. It's not quite as sexy as saying "I have so and so lift", but it was built along the way and works great for me. I love MC products but most the time I have a hard time paying full retail on top of shipping for them, so end up buying a different brand that is discounted like Rock Krawler. I will say that I paid up for MC arms and have not had one bit of remorse. I was sold on the bushings they use mainly.....and what seemed like a bit more of a maintenance free joint.....although they do recommend re-greasing those once a year which essentially means uninstalling and re-installing the arm. I have a couple buddies that like to egg me on about them being "maintenance free". I had to learn my lesson the hard way with my build.......and that is more expensive than buying quality componenets the first time round. LOL. I heard this little phrase a few years back and it rings in my head in almost everything I do these days -- "if it's worth doing, it's worth doing right". All the adjustable arms on the market are going to accomplish the same thing. The difference will be the types of joints they use and maybe the angle of bends in the arms themselves. Do a little research on the various brands and go with your gut. Most the manufacturers continue trying to improve their product. Synergy has moved to a MC-like bushing in a lot if not all of their products, and Rock Krawler has improved the joints in their products as well. EVO makes good products too. Don't know anyone running Teraflex or currie arms myself, but they are obviously name brands as well.

BigRich26

Ordered Core 4x4 Tier 3 front control arms. Next paycheck I'm ordering the Synergy draglink and possibly an upgraded tie-rod.

kjeeper10

Those Tier 3's are sweet.

resharp001

Are you planning on flipping your DL when you replace it? I'm about to do a flip when I truss my axle in a couple weeks (hopefully), and have been considering options. Was kind of looking at the Steer Smarts no-drill option -

https://www.northridge4x4.com/fits/2...r-draglink-end

BigRich26

Not sure if I'm going to flip my DL or not yet. I'm also going to upgrade my tie rod I think, not sure about that yet though.

resharp001

TRs are neither cheap nor a sexy upgrade, but if you're gonna do any real wheelin' it's worthwhile. That factory TR bends pretty easily.