How to tell if lower control arms are bad

If the ball-joints are bad they can be replced by themselves and leave the arm alone. The reason arm replacement can get expensive is because the cam bolts often have to be cut out. It's a pain in the butt and adds extra labor and parts

Prying on the rubber bushings is fine but even new ones will squeeze and move when you pry, movement doesn't necessarily mean they're bad. You have to look in there and see if the rubber is cracking and falling apart resulting in excessive movement. Even a few cracks in the bushing can be normal

When bushings get really bad you can hear a clunk sound when braking. When the brakes clamp down at the wheels all the weight of the vehicle goes through those bushings. If there's too much play you'll be able to hear and feel them shifting around

Mechanics love to sell control arms because it's relatively easy and they can charge good money. But I see a lot of arms getting sold just because of "age" or a few cracks in the rubber

 

You know what's really interesting ever since I bought this truck there has been a slight thump feeling sometimes when coming to a complete stop or when accelerating from a complete stop. I've heard it could be a poorly lubricated slip joint on the drive shaft but I lubed it up and that's not it. When I saw that video I was wondering if the play in these bushings could be cause. Sounds like it might be

 

Stay away from aftermarket arms. It's a 50/50 gamble as to how long the ball joints/bushings will last or whether or not you'll have persistent alignment problems.

 

If the same noise happens on decel and accel I'd suspect a driveline issue. That slip yoke thing is fairly common. But also my truck makes some gentle thumps and whatnot from the driveline and rear axle at times coming to a complete stop. It's noticeable but I'm not particularly concerned. It's a truck with a long driveshaft and a big old rear axle that likes to flop around a bit

Any noise on acceleration usually isn't going to be related to the front suspension because the driveline goes to the rear suspension (assuming you're not in 4wd)

Most of the braking work is done at the front wheels. So a noise heard only while braking could be traced to the front suspension. And I mean sharp braking, not gentle braking. Try getting up to speed and then getting on the brakes kinda hard and sudden. If the front control arm bushings are bad you'll feel it right through the floorboards under your feet

 

Yeah I've slammed those brakes hard before and felt nothing. Actually just did this weekend and felt nothing. I've come to a very gentle stop and felt the thump seems pretty indeterministic.