I need a new driver side upper control arm. The vehicle hit something and snapped the upper ball joint. It mauled the threading that the 4000lb ball joint sits in to. The ball joint won't seat. Is t true that you can use a d100-d350 upper ball joint? For instance this ebay ad says that there is no threading in the upper ball joint seat and that the ball joint will create one as you put it in...here's the link

does anyone have experience in this

 

Had them strip. Welded them in. Good till the next time, then you must get the control arm. Hint ... Take the boot off while welding. Use short arc wire feed if possible.

 

The upper control arm from a D150 to D350 is the same basic part. The 2wd with a 4000lb front end will have a little extra bracket welded to the inside of the upper control arm, around where the bushings sit. FOr added strength in this area.

The actual ball joint for a 4000lb front end has the same body size of a D150/D250 trucks with the 3300lb front end, but the actual shaft on the ball joint, that runs down through the spindle, is bigger on a 4000lb ball joint.

And yes a new upper control arm will not have any threads. The new ball joint will cut it's own threads into the metal as you tighten it.

 

Someone else also mentioned welding them in and then just replacing the arm next time. Thanks, it's probably what we'll do.

 

Thanks for the help! I just had a hard time believing the ball joint would create it's own threads and wanted to check and make sure it was legit.

 

When you are a putting a new ball joint in, how tight does it need to be?

 

It needs to be seated. As I remember it takes a 3/4 breaker bar and a piece of pipe to get it done.

 

Is there a special socket for that?

Or, does it have a hex head? I have seen some that are round except for two edges. That makes for special socket, pipe wrench or large crescent wrench.

 

There is a special socket. There are two common sizes these take the big one.

I have not tried it myself but an old mechanic told me the best way to keep these in is run a short bead of weld on the flat sides so it can be ground off for the next replacement.