68 SDV Upper control arm differences LH/RH?

[taintedsaint]

I am restoring my 68 SDV, chassis back from powdercoat as well as all pieces, arms, crossmembers etc.
I had twisted a piece of steel wire through one of the bushing holes on the upper control arms to indicate right side. Even told powdercoater about it. Got parts back, no wire. They are impossible to distinguish but parts guide lists two different numbers for left and right. leading me to believe they ARE in fact different. Any input as to how I can tell them apart? Thanks in advance to any and all replies.

[Highwayman68]

There is nothing in section 12 or 13 of Chapter 3 indicating a need to identify a left or right piece. Perhaps someone else can see something in the manual that I don't.

[Scot Minesinger]

You don't say front or rear upper control arm, presume you mean front.  The ball joints are LH/RH specific on upper control arms (front).  The factory manual states that the control arms have to be purchased as a unit, because the ball joints are welded in (you can always tell an original ball joint this way), and that was the case in the 1965-70 chassis - maybe other years too.  Accordingly the control arms if purchased as a part from the Cadillac dealer back in the day must have sold the upper control arms as a unit with ball joint - RH/LH specific, hence the part number issue.  BTW rear upper control arms should be same R or L.

Presuming the control arms are less ball joint so you should be OK.  For future, metal stamp R or L next time, as you can be sure any other non-permanent ID will be removed - you can bet your house on that.

[taintedsaint]

Thanks Scot, I figured you would chime in 
The 'replaced as a unit' is exactly where I was concerned because of the different part numbers but I also assumed different because of the joint, not the arm. These were original ball joints, car only had 18K miles on it though sat garaged since '72. I will certainly go with stamping them or filing a small notch somewhere versus the twisted wire for ID. I've sat them side by side, on top of each other etc on bench and all measurements are identical so I'm going with interchangeable before joints installed.

Thanks again to all.
Chassis looks good in fresh powdercoat

[Scot Minesinger]

Joe,

Nice powder coated frame!  When you connect the starter to frame ground strap and battery to frame ground, make sure you have good metal to metal contact.  I worked on a powder coated frame car once for a friend and the resolution to electrical troubles was to scrape a small portion of the powder coat off at these connections to get a good ground.  This made a huge difference.

Enjoy your Cadillac!

[cadillacmike68]

The upper control arms Are interchangeable until you tack weld a ball joint in them.

[taintedsaint]

Thanks for the compliment Scot, frame really did come out well. All the other chassis parts at coaters now. I planned out my ground points and had them apply a silicone sticker over the locations to save headache later. I know I'll have 10x what the car would sell for in it when I'm done but I plan on keeping it till the gov't drags it from me for polluting the squirrels or whatever.

Thanks to all for your help on control arm issue.

[DeVille68]

There was a thread recently discussing this topic before. As Mike, said, those are identical, just the balljoints are different.
You can get some reference on my thread here: http://forums.cadillaclasalleclub.org/index.php?topic=130360.200
I will soon update the thread with a post on how to install new balljoints.