C2 Power Steering Relay Rod Vs C3 Rod

[Sheldon S.]

Was there a difference in diameter of the power steering relay rod between C2's and later production C3's. I have the relay rod of my 71 and it appears to be about 7/8 of an inch thick and I have another one off I think a 66(not positive) and it is about 3/4 inch in thickness. I was going to use it on my 65 but want to make sure it is correct.
Thanks
Sheldon

[Wayne W.]

Re: C2 Power Steering Relay Rod Vs C3 Rod

Was there a difference in diameter of the power steering relay rod between C2's and later production C3's. I have the relay rod of my 71 and it appears to be about 7/8 of an inch thick and I have another one off I think a 66(not positive) and it is about 3/4 inch in thickness. I was going to use it on my 65 but want to make sure it is correct.
Thanks
Sheldon

Yes, the early ones are smaller.

[Joe L.]

Re: C2 Power Steering Relay Rod Vs C3 Rod

Was there a difference in diameter of the power steering relay rod between C2's and later production C3's. I have the relay rod of my 71 and it appears to be about 7/8 of an inch thick and I have another one off I think a 66(not positive) and it is about 3/4 inch in thickness. I was going to use it on my 65 but want to make sure it is correct.
Thanks
Sheldon

Sheldon------

It's not exactly a C2 versus C3 difference here. 1963-68 Corvettes used 3/4" OD relay rods for both manual and power steering. 1969-82 Corvettes used 7/8" OD relay rods for both manual and power steering.

In 1969, the 1969 power steering relay rod became SERVICE for 1963-68 Corvettes with power steering. The 1969 manual steering relay rod became the SERVICE relay rod for 1965-67 Corvettes with big block and all 1968 Corvettes. The 1969 manual steering relay rod has no provisions for steering shock absorber.

So, what about 1963-67 Corvettes with small block and steering shock absorber? Did they continue to use the original 3/4" rods for SERVICE? Nope, they did not. A special, SERVICE-only 7/8" relay rod with provisions for steering shock absorber was released for them in 1969. This was GM #3955521. I've never seen one of these.

So, why did GM change to the 7/8" relay rods in 1969, immediately change the SERVICE rods for 63-68 applications to the 7/8" rods, and, even, release a special, SERVICE-only 7/8" rod for 63-67 applications with steering shock absorber? Well, you can bet it didn't happen because the 3/4" rods were just as good as the 7/8".

[Wayne W.]

Re: C2 Power Steering Relay Rod Vs C3 Rod

Sheldon------

So, why did GM change to the 7/8" relay rods in 1969, immediately change the SERVICE rods for 63-68 applications to the 7/8" rods, and, even, release a special, SERVICE-only 7/8" rod for 63-67 applications with steering shock absorber? Well, you can bet it didn't happen because the 3/4" rods were just as good as the 7/8".

You can bet your Sweet Bippy it wasn't.

[Sheldon S.]

Re: C2 Power Steering Relay Rod Vs C3 Rod

So is it safe to use the smaller diameter rod with a small block car or should I get the larger one. Have they been known to bend or break with power steering installed?

[Joe L.]

Re: C2 Power Steering Relay Rod Vs C3 Rod

So is it safe to use the smaller diameter rod with a small block car or should I get the larger one. Have they been known to bend or break with power steering installed?

Sheldon-----


That's a very difficult question to answer because the term "safe" is a relative one and not an absolute. Certainly, there are a lot of 1963-68 Corvettes out there with original relay rods that have never experienced a problem. In fact, I don't know of even one that did. However, my "information base" is a LOT narrower than GM's.

I always figured that the 1969 change to the 7/8" rods was the result of some experiences of the 1968 model year when the first use of wider tires for that year "collided" with the 3/4" relay rods and resulted in in-service problems.

However, the above would not explain why the 63-67 rods for both big block manual and all power steering applications were IMMEDIATELY dropped and replaced by the 7/8" rods. Of course, the 69+ rods used for PRODUCTION were immediately available for earlier SERVICE, were directly retrofittable to many 63-67 and all 1968 applications, and were, reasonably, an improved part.

The REALLY BIG indicator, though, was the immediate release of the SERVICE-only 7/8" rod for 63-67 small blocks with steering shock absorber. This was a piece never used for any PRODUCTION application and likely required a significant investment in new forging dies and tooling. I very much doubt that occurred on a "whim" and without evidence of any problem with the 63-67 original rod.

So, I would say that the "short" of it is that any 63-68 Corvette is "safer" with the 69+ steering relay rods. That does not mean, though, that they are "unsafe" with their original rods.

For folks with 63-67 small blocks with steering shock absorber ("damper") and wishing to maintain the shock absorber, but inclined to conversion to the 7/8" rod, things will be, indeed, difficult. As I previously mentioned, I've never even come across one of these SERVICE-only, 7/8" rods with steering shock absorber provisions.