Ball Joints

robsad

True Classic
I recently bought a pair of rear control arms from MWB. Pictured are the components. The Ball joints are tight and smooth. I assume when these were put together originally they coated the ball with grease so there was grease behind the ball. Now when I assemble things I can't see any way to force grease into the back of the joint without a grease fitting. Is the foam donut supposed to absorb the grease and wipe the balls surface ? How much grease should go into the boot ? Finally, I can't see how the boot is going to stay in place. There is no groove or lip to hold it. When I push the boot down, hold it in place and try to simulate how it's actually going to move in service it pops right off. Thanks in advance,

Bob

IMG_1313.JPG
 
Last edited:
Bob, unfortunately these joints are not serviceable. There is no provision to grease them nor rebuild them. Although there have been companies that tear them open and attempt to refurbish them, I'm not sure how well that works. That's why they are so expensive to buy new - if you can find them.

They should be sealed around the center ball (where the post comes up) to keep any existing grease in and dirt/water out. So no need to to put grease in the boot as it won't get into the joint.

Those boots are not the factory ones, they are a "universal fit" aftermarket item. That's why they don't stay in place, and likely why the foam ring was added (don't normally exist in a joint boot) to help keep the joint clean. There are other universal aftermarket boots available online that might(?) fit better, but they would have to be tried to find out. Otherwise just assemble them as they are.
 
The (used, lifetime warranty) rear control arm I got from MWB had the boot installed. Yours did not? Have you called them in that case?
 
My original rear ball joints have the foam insert. The boots have an integral metal collar that holds them in place. I bought a new set of joints from Germany that use a separate metal ring to hold the boot on place. The joint has a machined collar to keep the boot from popping off.


Bob, unfortunately these joints are not serviceable. There is no provision to grease them nor rebuild them. Although there have been companies that tear them open and attempt to refurbish them, I'm not sure how well that works. That's why they are so expensive to buy new - if you can find them.

They should be sealed around the center ball (where the post comes up) to keep any existing grease in and dirt/water out. So no need to to put grease in the boot as it won't get into the joint.

Those boots are not the factory ones, they are a "universal fit" aftermarket item. That's why they don't stay in place, and likely why the foam ring was added (don't normally exist in a joint boot) to help keep the joint clean. There are other universal aftermarket boots available online that might(?) fit better, but they would have to be tried to find out. Otherwise just assemble them as they are.
 
I think there is a good chance that when mounted, the pillar will hold it in place. There is not much room for it to go anywhere.
 
My original rear ball joints have the foam insert. The boots have an integral metal collar that holds them in place.
I had not found the foam piece before, thanks for the correction Mark.

On what I believe are the original boots on my cars, some have a 'crimp on' metal ring and some have a spring steel wire retainer, depending on location....similar to these examples:
boot-850x850_0.JPG
images.jpg

That second type (with the spring steel ring) is available on many aftermarket universal fit boots, and should seal well on the lip of the stock joint.
 
I think it good protocol that when you get a part from a vendor and have issues or questions about it that you first contact the vendor.
 
Back
Top