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Quick question. On the aluminum LCA crossmember, I'm trying to see what Chevrolet did. Do the LCAs bolt/tighten directly against the aluminum "tabs", or are there any steel washers between the LCA bushings and the aluminum tabs?
I'm getting nearer to fabricating version 2.0 (aluminum) of my LCA crossmember, and I'm assuming I'll need washer clearance in the pocket where the LCA bushing reside, unless there's a reason I don't need/want steel washers in there.
Thanks.
The lower control arm are attached via GM cam bolts - that is how you adjust the camber and caster. There is a steel tube (at least, presume steel but I never tested it) that keeps the bolt from crushing the rubber bushing which keeps it from the arm. The cam is steel on cast aluminum.
The upper arms are forged aluminum, however the inner sleeve is steel, as are the tabs and the bolts are steel as well. The bolts go through steel tabs that are floating in rubber in the arm itself
To the bottom arm adjustment - I presume GM knew what they were doing - and as these parts had 100k on them and there is no corrosion - I can only presume that the alloy is important here.... and in my experience some kinds of aluminum are far more susceptible to galvanic corrosion then other alloys.
In the boating world, it's stainless steel/aluminum that makes the aluminum the anode to stainless steel.... regular steel? not my in my experience. There are 12 points where they touch, 8 of which were GM-designed.
Good question - I'll give a qualified "I dunno" but with the caveat that this is why I kept it all GM, I think GM's QC is world class
and of course, I can't even imagine trying to drive this car in a situation where salt is on the road, I can't get it up my driveway if the gravel is even slightly moist. Thankfully, I'm not GM and I'm not building my cars to protect the darwin end of the gene pool.