Lower ball joint binding on dropped crossmember

[crakarjax]

tl;dr is there a problem with running ball joints near their extreme angles/rang of motion?

I'm planning to go air and when setting up my suspension I notice that a couple of inches prior to the LCA hitting the crossmember, the lower ball joint is at max travel. Is there a way around this with stock control arms?

In reality I'll probably never go this low -- planning on plates and cups with a 3"ish max compression bag. BUT this makes me wonder how those extreme angles will affect the life of the balljoints.

I've seen flipped UCA's for correcting BJA (see attached pic) but I'm hesitant to do this, as the UCA isn't designed to carry a load in the opposite direction! Not sure how to deal with the LCA but I've read about "pie cutting" control arms to correct ball joint angle. I'd rather not do that if I can avoid it though.

[PBFAB.COM]

Originally Posted by crakarjax

tl;dr is there a problem with running ball joints near their extreme angles/rang of motion?

I'm planning to go air and when setting up my suspension I notice that a couple of inches prior to the LCA hitting the crossmember, the lower ball joint is at max travel. Is there a way around this with stock control arms?

In reality I'll probably never go this low -- planning on plates and cups with a 3"ish max compression bag. BUT this makes me wonder how those extreme angles will affect the life of the balljoints.

I've seen flipped UCA's for correcting BJA (see attached pic) but I'm hesitant to do this, as the UCA isn't designed to carry a load in the opposite direction! Not sure how to deal with the LCA but I've read about "pie cutting" control arms to correct ball joint angle. I'd rather not do that if I can avoid it though.

When running an adjustable air suspension this is always a key concern. The only way to know for sure would be to mock up the suspension components and determine if the ball joint is either maxed or binding.

You do not want the ball joint to be in a bind as it will cause failure. However, I wouldn't be concerned if the ball joint was at its limits (but not binding) at full deflation.

If you find that the ball joints are binding at full deflation, then you would need to look into finding a solution to relieve the angle.

Nate

[crakarjax]

Thanks, that is really helpful -- it's clear that I was misunderstanding the term binding as being maxed out. The joints are not in fact binding when mocked up, but are maxed out. What causes binding? Shouldn't the joints be designed not to bind through their entire axes of rotation?

[SCOTI]

Originally Posted by crakarjax

Thanks, that is really helpful -- it's clear that I was misunderstanding the term binding as being maxed out. The joints are not in fact binding when mocked up, but are maxed out. What causes binding? Shouldn't the joints be designed not to bind through their entire axes of rotation?

'Frame rails on the ground' low & BJ's reaching the travel limit shouldn't be an issue. If the BJ's bind before the truck lays out, it's going to be an issue. This can occur when using different combo's of parts & a large diameter wheel/tire set-up.

One option if it's an issue are 'uni-ball' or 'Jeebus Joints' (Google them). Usually it's the uppers that bind first.

[PBFAB.COM]

Originally Posted by crakarjax

Thanks, that is really helpful -- it's clear that I was misunderstanding the term binding as being maxed out. The joints are not in fact binding when mocked up, but are maxed out. What causes binding? Shouldn't the joints be designed not to bind through their entire axes of rotation?

Once the ball joint is out of usable travel... and then is required to articulate more, that's when it "binds".

Nate

[crakarjax]

So it sounds like if my suspension is designed such that the joints never reach max travel I shouldn't bind. On the other hand, is there ever a situation in which the joints are maxed out and the suspension does not bind? I think I'm still missing something because it seems like you're saying that it's OK to be at max travel, but to me that basically means that the ball joint is being required to operate further than max travel. I mean, what suspension has such a tight tolerance that the joints can be maxed out by design with no further suspension travel possible?

[SCOTI]

Originally Posted by crakarjax

So it sounds like if my suspension is designed such that the joints never reach max travel I shouldn't bind. On the other hand, is there ever a situation in which the joints are maxed out and the suspension does not bind? I think I'm still missing something because it seems like you're saying that it's OK to be at max travel, but to me that basically means that the ball joint is being required to operate further than max travel. I mean, what suspension has such a tight tolerance that the joints can be maxed out by design with no further suspension travel possible?

By design.... Like setting up your suspension so the the frame is touching the ground @ the same time the BJ reaches its operating limits. Once it hits the ground, you're pretty much out of travel range.

[crakarjax]

Yeah I guess so, I think my joints will max out way before I hit frame though -- not that I'm looking to.

[SCOTI]

Originally Posted by crakarjax

Yeah I guess so, I think my joints will max out way before I hit frame though -- not that I'm looking to.

This is where guys start 'pie-cutting' the arms to reduce the angles (or step up to aftermarket arms/cross members).

[crakarjax]

Originally Posted by SCOTI

This is where guys start 'pie-cutting' the arms to reduce the angles (or step up to aftermarket arms/cross members).

I guess that means cut a pie slice/bend/re-weld? I don't think I trust my welding skills all that much but maybe I'll give it a shot on the takouts after I swap this suspension out. Again, not planning to go that low at this point but you never know what will happen in the future! Thanks for all the advice, guys.