Hi Guys simple question. I am replacing my lower ball joints but I am not sure which side the Bolt with the Big head should go.  A manual I checked tells me it must go on the forward side but a few guys are telling me it should go on the rear side!(also, what is there purpose) Thanks in advance.

It goes on whichever side the steering limit "stop" is on, normally the rear on our cars. The purpose it to give the spindle a positive "stop" when turning, so it doesn't just keep turning.
If you look on the spindles, you will see a large bracket made on to the spindle in front or rear...that is the side the big headed bolt goes to. I'll see if I can locate a pic...Adams' Apple2007-04-10 05:32:35

Well...I gotta confess, this one got me! I don't know why I didn't catch it sooner, but...the ball joints should be riveted, to begin with. The replacements are normally bolted on, tho.
Anyway, I believe the larger headed bolt should be in the front, but, it really doesn't make much difference...it's not gonna touch anything anyway, as far as I can see. I did go out and take a couple of pics of my front ball joints, just for the heck of it. They are still factory riveted, but you can see where nothing even comes close to touching them when the front spindle turns.


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I put lower ball joints in a GM car(don't remember what, tho, maybe an Impala) years ago and remember the replacement had one bolt that had a hugh head on it. Maybe the size of a bottle cap. Didn't know what it was for then and don't know what it would be for now!! Like Joel pointed out, don't think it's necessary on the Vettes.