screw in upper ball joint ? - Lateral-g Forums

62fairlane · #1 11-09-2005, 03:21 PM

ok so today I got a box of junk from speedway motors. in it was two screw in upper ball joints (mopars?) but looking at them there is hardly any thread on them? it looks more like tool drag marks then threading. is this normal and when threaded into the arms they "Bite in"? I don't yet have my arms so I don't know what the deal is with them

B Schein · #2 11-09-2005, 03:33 PM

I would say if looks like drag marks from tooling not threads, then they are not screw in ball joints and you already answered your own question. The difference between the minor and major diameters of the threads should be significant on a course thread.

How about some pictures of them.

62fairlane · #3 11-09-2005, 04:08 PM

the difference is roughly .020" max.

http://photobucket.com/albums/v701/p...t=DSCF0026.jpg

they have the sqaured end for a spaner wrench and do follow a uniform threading pattern.....BUT very shallow threading

B Schein · #4 11-09-2005, 05:54 PM

It doesn’t look like a thread to me. Is there actually a lead on them it looks more like ridges so that try to dig in once they are pressed into place.

**Autokraft** · #5 11-09-2005, 06:44 PM

62 Fairlane,

Don't worry about the ball joints. That is normal. If you look at a factory one they will look the same. I know they don't look like they really have threads but thats they way chrylser made those. They do screw in, hopefully you have the correct tool for installing them and make sure you grease the threaded parts before you try turning them in otherwise they will weld themselves to the control arm by galling the thread and make sure you turn them in straight and not cross threaded.

Hope this helps,

Kurt

www.autokraft.org

62fairlane · #6 11-09-2005, 07:02 PM

yeha I bought the spanner too....I was almost afraid I got scammed if they could just be pressed in...sweet...I think we have the geometry finalized so can order the upper arms this week.

**XcYZ** · #7 11-09-2005, 07:07 PM

I believe it's supposed to hold 150 ft/lbs of torque. If it slips/strips at 150 ft/lbs, you have a bad control arm.

B Schein · #8 11-09-2005, 10:03 PM

Well that show what I know. I have never had any experience with these style ball joints. It is interesting that they use a lead that is very shallow, but I guess it effectively cross threads it self into place making it work like a lock nut or tapered thread.