So I keep breaking upper balljoints, truck is a 08 Ranger 4.0l 4x4 automatic. I have replaced the driver side 2 times and now the passenger once within 20,000km no off roading or anything, just highway, city and gravel roads. Ever since the first one broke I've been driving with the fear of it happening again so it shouldn't be "driving habits" causing this. I need some of your guys ideas on why this might be happening. The balljoints shear right at the knuckle surface. I am currently thinking that the knuckle balljoint opening is hollowed out which is causing some back and forth movement which is allowing it to shear. Let me know what you guys think. Tires are 285/70R17 with if I remember correctly a 1.5inch wheel spacer. I have some wear and play in my steering rack which is causing a wobble on the highway but I don't think it should affect the balljoint, atleast to this extent but figured I'd bring it up anyway. Also, does anybody have the torque spec for the upper ball joint pinch bolt?

 

 

Looking at your pictures, the break is happening in the groove where the pinch bolt should be, but you said that it breaks at the top of the knuckle. Is it possible that the ball joints were not inserted all the way? The pinch bolt should be in the groove so the ball joint is locked in by the pinch bolt even before the nut is put on the bolt.

 

Thanks for pointing that out, I was wrong and you are right. Yes the ball joint is pushed in all the way when installed. Any idea why it would be breaking at the pinch bolt groove?

 

I have never heard of this before so all I can do is guess. My guess is that the combination of the spacer and wheel offset is stressing the knuckle beyond the design limits.

 

I've considered that but the offset isn't very drastic. I've seen rangers with quite a bit bigger tires and I'd imagine that broken balljoints would be a more common topic if wheel size was the issue, but I could be wrong.

 

Heres a picture to show the offset of the whole wheel (The box is full of dirt in this picture)