Lower Ball Joint in Tension

[XR250]

On my 1st Gen Tundra, lower BJ failures are common. So common that it is standard practice to replace them with OEM every 100k miles. Toyota had a recall and improved the joints but the failures persist.
Seems the issue is the suspension is designed so the joint is in tension. Spring/shock attached to LCA, stud pointing downwards.
Is it common to design suspension like that? It would seem having the joint in compression would be safer.

 

[tk90]

It is not- most (modern) double wishbone suspension designs will have the LBJ in compression.

The only two applications I am aware of are the Tundra and some generations of the Honda Accord.

 

[BrianPetersen]

Lots of older suspension designs were that way. The traditional American-car upper and lower wishbone suspensions with the spring acting on the lower control arm were that way for decades. All of the Ford Fox body cars, Mustang, Fairmont, etc (MacPherson, but with the spring separate from the strut and acting on the control arm) were that way.

 

[GregLocock]

Up until a couple of decades ago there was no recommendation either way. Then a whole bunch of manufacturers ran into durability failures in service that hadn't shown up in testing. In at least one case it turns out the boot manufacturer had surreptitiously changed the material used for the boot over the joint, to the extent it no longer met the rig test KPI. Once the boot cracks, water and grit get in, lubricant comes out. So long as your boot isn't cracked you should be OK.

I am told the ball joints themselves aren't a serviceable item on some SUVs, you have to buy a whole new arm.

 

[LostInTransit]

Right, we've had to replace the lower ball joints/ control arms on the van twice allready in the last 4 years.. I think next time instead of buying just the ball joints installe don the control arm , we'll get the control arm that has the option to installed new ball joints whenever one is needed and keep the may control arm if deemed worthy of being kept.. Look into thing like the mevotech control arms with removable or adjustable lower ball joints. this way it would be a much easier installed. I've even went as far as to installed thing like mevotechs "over engineered" products on the van.

 

[XR250]

Lots of older suspension designs were that way. The traditional American-car upper and lower wishbone suspensions with the spring acting on the lower control arm were that way for decades. All of the Ford Fox body cars, Mustang, Fairmont, etc (MacPherson, but with the spring separate from the strut and acting on the control arm) were that way.

Do they all have the ball joint facing in the direction so it is in tension?

 

[GregLocock]

If this it , yes

 

[XR250]

Yup.