Upper ball joint failure

Hello everyone,

A close friend was driving his 4runner through a roundabout and said he suddenly couldn’t steer his 4Runner.

2018 4Runner TRD Off-road ~ 70k miles. It came with a spacer lift when purchased new from Toyota..

 

Not sure if the spacer lift was directly responsible, but that’s one of many reasons why I removed my spacer lift. I was alarmed how the UCA was binding into the front coil springs when I jacked the front end off the ground. I don’t miss the lift or 285’s at all except when I do the oil change, the extra ground clearance helped with that.

 

Depending on how thick that spacer lift was, it most definitely could be the cause. On something so new and rust free, it’s actually the prime suspect.

A spacer lift (tophat spacers) can cause this problem because it’s the shock that ultimately limits the down travel of the front suspension. A spacer lift lowers the entire shock down, allowing the upper and lower control arms to extend further down, potentially to the point it over extends the joint and dislocates the ball/socket. So all it takes is a few good whoops on the road that would top out the suspension, and it would pop right out.

 

It’s why UCA’s are recommended for lifts too.

 

I have never been a fan of spacer lifts. I too would guess it is the culprit. Just a little food for thought for people who consider spacer lifts or have purchased their 4Runners with them installed. I’ve also seen the bottom of shocks bend because of the limited travel.

 

this right here. spacers add droop. without the right hardware things like sheered ball joints can happen because its angle limit is exceeded.

most aftermarket UCAs have the same angle limits as a factory UCA, particularly the ones that use a factory style ball joint but spherical bearing UCAs still have a similar limit. Long travel UCA corrects this angle problem through length, but usually still have the same limits at the ball joint.

It's actually the changed up-travel since the top of the shock is moved downward with a spacer. The shock bottoms out sooner and becomes a bump stop handling all of the upward force instead of the bump stop on the frame limiting the LCA.

 

I wonder if is those plastic spacers they promote a lot on forums etc.

 

According to Tinker’s Garage. The shock always limits down travel regardless of lift or no lift. The problem with the top hat spacer as I personally discovered is that it allows too much down travel which in my case allowed the UCA to hit the coil spring.

 

Oops, accidentally got that ass backwards. Thanks for the reply!

 

i did too. the shock is actually bottoming out and not topping out. ahh well.

hope your friend is ok and is able to get his rig back on the road soon.

 

That’s only true if it’s true. The shock should be what limits down travel. But when you get a top hat spacer, you move the entire shock down, which means the fully extended position location is further down in the travel as well. If the spacer is thick enough, the shock cannot act as the limiter because maximum UCA balljoint extention will happen before the shock is completely uncompressed.
The uCA colliding with the coil is also another possibility depending on the coil I guess.

If you lift using a suspension lift, the new coilovers are usually the same extended and compressed lengths as original shocks (unless longtravel). The lift is accomplished by a longer spring or some preload. Not by entirely moving the shock down.

As mentioned, it’s also possible to compress it far enough that the LCA wont touch the bumpstop on the frame, because the shock is now low enough that it becomes the bumpstop, which is basically just crushing the shock when fully compressed.

 

Yep, that was my point.

 

Ah, I get it. forgive my understanding. Sometimes I get too excited when I learn a thing lol. And those Tinkerer videos are filling me with learnin.

BTW I had just edited clarifying the reason why a coilover vs a spacer lift will preserve the factory UCA extension range

edit: me after a Tinkerer video