66 Strut Arm

[Ed K.]

Gentlemen:

I'm restoring the rear of my 66 427. The differential gasket was bad and it led to refinishing everything back there. One "expert" told me the strut in the attached photo is not correct. It's for an 80-82. He claims the bushing sleeves should be perpendicular to the arm, not angled as per my photo. Another "expert" claims they're correct. I bought the car with these arms there. I've never previousdly had them out and have driven the car since 82, problem free. Incidentally, the part is painted because I live on a salt water bay and parts cannot be left without paint.

Also, if the strut is correct, I believe when attached to the differential they angle towards the front of the car?

[Rich P.]

Re: 66 Strut Arm

Ed,

there were 2 different strut rods (that I know of) 63-74 had a 1-1/8" bushing on either end and 74-up had a 1-1/4" bushing. It is hard to tell from the picures what they are. If you measure the busing openings on the ends you'll answer your question.

Rich

I wanted to edit this as I think the 63-74's are 1" not 1-1/8" like I said above.

[Ed K.]

Re: 66 Strut Arm

I did not replace the rubber bushings so they are somewhat flattend and spread, but they appear to be 1.25" dia. What about the angled sleeves?

[Terry M.]

Re: 66 Strut Arm

I did not replace the rubber bushings so they are somewhat flattend and spread, but they appear to be 1.25" dia. What about the angled sleeves?

The bushings, and sleeves, should not be angled. As they deteriorate they will take on an angle. The original style, smaller diameter, bushings will last longer and give a harsher ride. Less rubber to deteriorate and flex as the wheels go up and down. Like many things in life these bushings are a comprimise.

[Joe L.]

Re: 66 Strut Arm

I did not replace the rubber bushings so they are somewhat flattend and spread, but they appear to be 1.25" dia. What about the angled sleeves?

Ed-----


I'm confused as to what these are if the bushing orifice in the rods is actually 1.25". 1963-74 Corvettes used rods with NO offset to the rod ends AND 1.25" ID bushing orifices.

1975-79 Corvettes used rods with NO offset ends and 1.375" ID bushing orifices. These rods also became SERVICE for 1963-74.

1980-82 used rods WITH offset ends and 1.375" ID bushing orifices.

So, if these rods actually have 1.25" bushing orifices, then I don't know what they are. They might be for some other applications or they might just be distorted 63-74 rods. In either case, they're unusable for any 63-82 Corvette.

IF the bushing orifices are actually 1.375" ID, then I'd say they are the 80-82 rods, GM #14010399.

[Michael H.]

Re: 66 Strut Arm

He claims the bushing sleeves should be perpendicular to the arm, not angled as per my photo. ?

I see the angle that you're describing. The entire end appears to be at some angle other than 90* to the length of the shaft. (more like 85*?) I thought all were at or very near 90*.

[Dale S.]

Re: 66 Strut Arm

I know how I would fix them. D/

[Joe L.]

Re: 66 Strut Arm

I see the angle that you're describing. The entire end appears to be at some angle other than 90* to the length of the shaft. (more like 85*?) I thought all were at or very near 90*.

Michael-----


All except 80-82.

[Michael H.]

Re: 66 Strut Arm

Michael-----


All except 80-82.

Thanks. I just learned something. I know very little about later C3's. (or early C3's, for that matter)

So the rods shown in Ed's photo could be 80-82?

[Joe L.]

Re: 66 Strut Arm

Thanks. I just learned something. I know very little about later C3's. (or early C3's, for that matter)

So the rods shown in Ed's photo could be 80-82?

Michael-----


Yes, but only if they actually have 1-3/8" ID bushing bores. All 75-79 and 80-82 rods use 1-3/8" OD bushings.

[Ed K.]

Re: 66 Strut Arm

If my struts are 80-82, and I bought the car from a stranger in 82, maybe I have a complete 80-82 rear set up - meaning trailing arms, struts and strut bracket. Therefore, the 90 degree strut arms may not be right for my 80-82 set up. Are 80-82 trailing arms different?

Also, a friend has struts he purchased in Carlyle from a Corvette vendor. They have 90 degree sleeves (not angled as per my photo). But the rubber bushing outside diameter is 1 - 1/8th"???

[Michael W.]

Re: 66 Strut Arm

The differential and frame crossmember assembly is markedly different on the later C3s and is usually referred to as a 'batwing' due to it's appearance. A substantial amount of frame modification would have to be done to accommodate one of these on an earlier car.

Does yours look like a typical C2 assembly?

[Ed K.]

Re: 66 Strut Arm

Yes. Looks just like the drawings and photos in the mid-year shop and assembly manuals.

Thanks

[Joe L.]

Re: 66 Strut Arm

If my struts are 80-82, and I bought the car from a stranger in 82, maybe I have a complete 80-82 rear set up - meaning trailing arms, struts and strut bracket. Therefore, the 90 degree strut arms may not be right for my 80-82 set up. Are 80-82 trailing arms different?

Also, a friend has struts he purchased in Carlyle from a Corvette vendor. They have 90 degree sleeves (not angled as per my photo). But the rubber bushing outside diameter is 1 - 1/8th"???

Ed-----


1980-82 trailing arms are the same as earlier with two exceptions:

1) the parking brake cable bracket is welded on at a slightly different location (same as 78-79, but slightly different than earlier, and;

2) 1982 used a plastic shield for the outboard u-joints which was attached to the trailing arm with 4 self-tapping screws. Therefore, 1982 trailing arms have the 4 small holes at 90 degree intervals around the rear of the spindle support hole. SERVICE trailing arms for pre-82 models available after about 1982 have these holes, too.

I don't know how you're measuring the bushing diameter. However, the 63-74 bushing orifices are 1-1/4" (actually, more precisely, I think the orifice is about 1.21-1.22" if I recall correctly).

1975-79 and 1980-82 use a bushing orifice of 1-3/8" (actually, I think it's about 1.38" if I recall correctly).

[Ed K.]

Re: 66 Strut Arm

[quote=Joe Lucia (12484);452014]Ed-----

I don't know how you're measuring the bushing diameter. However, the 63-74 bushing orifices are 1-1/4" (actually, more precisely, I think the orifice is about 1.21-1.22" if I recall correctly).

I'm probably measuring in the wrong place. I've never seen an arm without the bushing in place so I'm not sure what a bushing assembly looks like. I measure the visible RUBBER portion of the bushing at 1-1/8th dia, as per photo. The outside diameter of the metal sleeve, immediately surrounding the rubber portion is 1.197" dia, as per the second photo. I'm now thinking that 1.197 metal sleeve is part of the bushing assembly? Was that originally 1.21 or so and got squeezed down when inserting? It's only .005" off, a paper thickness is around .003 or .004.

Thanks for jumping in.