Control arm bushing bolt finish

[Michael L.]

What is the finish for the bolts on the end of the control arm shafts? I have checked the TIMJG and the archives but I'm still not certain. Is it natural like the washer?

Mike

[Rich P.]

Re: Control arm bushing bolt finish

Mike, the upper and lower control arm bushing retainer bolts are Plated Black.

Rich

[John M.]

Re: Control arm bushing bolt finish

Boy, I would have gotten that one wrong. I thought they were Zinc as well as the Cup washer.

[Rich P.]

Re: Control arm bushing bolt finish

John,

actually the cup washers were natural bare steel.

Rich

[Michael L.]

Re: Control arm bushing bolt finish

Thanks again, Rich

[Patrick H.]

Re: Control arm bushing bolt finish

John,

actually the cup washers were natural bare steel.

Rich

If 69 and 72 are the same, then I would suggest that they were black phosphate as shown below.

Center of picture:


Right side of picture:


I highly suspect that they were either zinc plated or black phosphate in 1969, and bare steel would surprise me. The only exception is if they were bare, and then the control arm was painted - which sometimes happened.

Please let me know if a 69 was different than I expect.

Patrick

[Joe L.]

Re: Control arm bushing bolt finish

If 69 and 72 are the same, then I would suggest that they were black phosphate as shown below.

Center of picture:


Right side of picture:


I highly suspect that they were either zinc plated or black phosphate in 1969, and bare steel would surprise me. The only exception is if they were bare, and then the control arm was painted - which sometimes happened.

Please let me know if a 69 was different than I expect.

Patrick

Patrick-----


I think that's probably paint on your bushing retainers (convex washers). The retainers were natural steel. However, as you mentioned, the whole arm was sometimes dip painted after installation of the shaft, retainers and bolts and that's likely what happened in your case.

Actually, there was a change in the upper retainers used over the 63-82 period and that change occurred for the 1972 model year. 1963-71 Corvettes used upper bushing retainer GM #3710586. 1972-82 used upper retainer GM #9785742 and the latter also became SERVICE for 63-71 in March, 1977. However, while the retainers did change slightly, the finish remained the same.

[Patrick H.]

Re: Control arm bushing bolt finish

Patrick-----


I think that's probably paint on your bushing retainers (convex washers). The retainers were natural steel. However, as you mentioned, the whole arm was sometimes dip painted after installation of the shaft, retainers and bolts and that's likely what happened in your case.

Actually, there was a change in the upper retainers used over the 63-82 period and that change occurred for the 1972 model year. 1963-71 Corvettes used upper bushing retainer GM #3710586. 1972-82 used upper retainer GM #9785742 and the latter also became SERVICE for 63-71 in March, 1977. However, while the retainers did change slightly, the finish remained the same.

Noted.
I looked at pictures of all 3 cars, and all 3 have black on the retainers.
I'll be by them tomorrow so will check in person.

I suppose that for better corrosion protection you could finish them in zinc or phosphate and then paint them black. You'd then likely never worry about rust.

Patrick