hello !
67 - 69 Cadillac upper control arms
left GM no. 3633509
right GM no. 3633510
they look visually the same
can anybody tell me what is different about them?
thanks , Murray
Might be too obvious, but uhm, left and right?
The ball joints are definitely right and left dependent/biased and that is critical. The ball joints were welded to the control arms in factory production, so that is probably why. Plus they may look visually identical, but different slightly. I would keep what is left on the left side and right to right to be safe. Replacement ball joints are of course not welded in, but they remain right and left side specific.
Murray,
I think if you turn the control arms right side up you will see that the cut out (opening) in the center is off-set. The mounting surface where the ball joints fit are also angled differently.
Greg Surfas
Quote from: 1969cadillac on January 30, 2016, 03:47:37 AM
hello !
67 - 69 Cadillac upper control arms
left GM no. 3633509
right GM no. 3633510
they look visually the same
can anybody tell me what is different about them?
thanks , Murray
I agree with Mike here http://forums.cadillaclasalleclub.org/index.php?topic=133964.msg289444#msg289444 that they are only different if the ball joints are pressed in. GM did not sell the ball joints separately, so you could only buy the arm with ball joint from dealer back then. I have a bunch of these sets and they all look exactly the same with no ball joint. Chuck
Chaz,
The factory installed ball joints were welded in plus of course pressed in, so that is why they were left and right specific for one thing. They may look alike, but I would not have the guts to switch them and install a left ball joint in a right arm and then install. There could be some geometry or dimension you are missing as seen by the eye that would be very bad from an alignment and drive ability perspective.
If they were the same they would not have different part numbers.
There has to be a difference that is not very obvious.
Brian
Understood, and I put mine back on the same way. One easy clue is that you can see the threads from the ground strap screw so you know which side it came off of on the car :) Agree on the part numbers, but I also agree that it was due to the ball joints pressed in the arm. One clue that the manufacturing process was probably the same for each side it that a hole was drilled on the top side of each arm for the ground strap so that they probably could be used on each side at the factory...but I can't confirm :) If only a left and right part, why drill out both sides for the ground strap as only one is ever used. Chuck
Anything is possible.
I recently took apart and re-assembled a complete 1960 front suspension and those arms are totally different.
Brian
It was bugging me so I looked up in shop manual :)...I grabbed the '66, but the part number for 61-70 are the same and in the shop manual, 3-1, it states the arms are the same when the ball joints are not installed.
"The upper arms...interchangeable....previous to being welded into an assembly."
Brian's comment makes sense as that is before '61.
Chuck