65 Relay Rod diameter??

[Jerry G.]

I have a 65 FI with F 40 suspension. Non Power steering. I took it apart 11 years ago and it's going together pretty well. A problem is I've moved twice and boxed up my various parts. I think I've mixed some up. My question is I have two relay rods that appear to be identical except for the diameter of the Rod. One is .750 inch and the other is .875 inch. WHICH ONE IS CORRECT???? Its tough to get old and move. Jerry

[Joe L.]

Re: 65 Relay Rod diameter??

Jerry-----

The original rod was 3/4" OD. The 7/8" OD rods were used from 1969-82 for both manual and power steering. Thye were also used for 63-68 SERVICE after about the mid 70s.

[Wayne M.]

Re: 65 Relay Rod diameter??

Jerry --- The F40 relay rod dia. is 15/16" for either FI or L78. The standard L78 rod diameter (no F40) is 7/8". These are quite subtle differences, and dirt or paint might throw off a measurement.

[Jerry G.]

Re: 65 Relay Rod diameter??

Does the F 40 Relay Rod have the holes for the steering Dampener. I know the FI cars don't have the steering dampener because of clearance problems with the oil pan, but did the relay rods have the holes left blank ie 5 holes vs 3.

[Jerry G.]

Re: 65 Relay Rod diameter??

So if I understand your answer Joe. All 65 Relay Rods were .750. Correct? Did they all have 5 holes. ie unused damper holes for non power steering cars with 6 quart oil pans.

[Joe L.]

Re: 65 Relay Rod diameter??

Jerry-----

I think that Wayne was referring to sway bar diameters, not relay rod diameters. There was no difference between relay rods for standard suspension and heavy duty suspension Corvettes; they were exactly the same.

For small blocks, all 63-67 manual steering relay rods were the same and all had holes for the steering dampner. The holes were unused for SHP Corvettes with "6 quart" oil pans.

For 65-67 big blocks a different rod was used. As I recall, it was still a 3/4" diameter rod; I don't recall, at the moment, if it had the steering dampner holes, or not. For sure, the big blocks did not use the steering dampner, though.

[Joe L.]

Re: 65 Relay Rod diameter??

Jerry-----

All 1965 small block relay rods for manual steering (or power steering, for that matter) were 3/4" diameter and had the holes for the steering dampner, although the steering dampner holes were not utilized for "6 quart" oil pan small blocks.

I think that the 65-68 big block relay rod was also 3/4" OD, but I'm not certain, at the moment. I don't know if it had unused dampner holes, or not, but the big blocks did not use the steering dampner.

[Jerry G.]

Re: Thanks Guys ! *NM*

[Craig S.]

Re: 65 Relay Rod diameter??

Joe - were the SB and BB relay rods functionally interchangable? Or, for clearance reasons on the oil pan were they shaped differently? For my 66 BB car, I purchased a power steering kit from Vette Brakes, and I am curious now if I have the correct relay rod...any way to tell by looking at them? I have my 67 L79 SB up on my hoist and can compare...if I know what to look for...thx!...Craig

[Wayne M.]

Re: 65 Relay Rod diameter -- oops !

Jerry --- Joe's right, I was thinking about sway bar (the years take their toll). Yes, the L78 had the same 3/4" relay rod as the small blocks; and all had 5 holes. I think there's even a Tech Service Bulletin on (say, 24) early L78's that had sway bars that interfered with the pan, before being eliminated as the base 396 installation, although I don't know why the pan contact, as L78's could be had with N40 (same oil pan), and the power and non-power rods are not THAT different in the middle.

[Joe L.]

Re: 65 Relay Rod diameter??

Craig-----

First of all, if you're talking about a POWER STEERING relay rods, they were the same for both small and big block cars. However, the original 63-68 rods were 3/4" and 69-82 were 7/8". The 69-82 relay rod became the SERVICE part for all 63-67 power steering applications when the 3/4" rod was discontinued more than 30 years ago.

For manual steering applications, at the moment, I don't know what the difference was between the 63-68 small block rod and the 65-68 big block rod. I THINK that it may have involved the fact that the big block rod lacked provisions for the steering shock absorber, whereas ALL small block rods of the 63-68 period had it. But, I'm not sure. I don't think that there was any difference in the "shape" of the rods for clearance purposes and I'm pretty sure that the original 65-68 big block relay rod was a 3/4" OD rod. For 1969 and later, when the 7/8" rods came into PRODUCTION, the big block and small block rods were the same, although no chassis or oil pan changes occurred at that time. So, if different rods were required for big blocks and small blocks due to chassis or oil pan interference problems, then the same should have been true for 69+. But, it wasn't.

The really interesting thing here is this: GM did not replace the 63-68 original big block relay rod with the 69+ 7/8" relay rod which was used for ALL 1969+ manual steering applications AND for 1963-68 small block SERVICE after 1969. GM replaced the 65-68 big block relay rod with a SERVICE-only rod which was unique to the 65-68 big block application. So, this would strongly imply that there was a need to continue to have a unique part for 65-68 big block applications. I know that this SERVICE-only rod was a 7/8" diameter rod, and I expect that it was otherwise the same as the original 65-68 big block rod. I just don't know what the difference was between the 65-68 big block rods and the other rods. I'd like to know, though; I've wondered about this for a long time. I've just never been able to acquire a KNOWN-original example of either the original rod or the SERVICE-only rod.

[Craig S.]

Re: 65 Relay Rod diameter??

Thx Joe - I was inquiring about the power steering relay rods. If I read your post correctly, the power steering rod supplied by Vette Brakes will functionally work, but, may be a 69-82 7/8" version versus 3/4". The manual steering rod on my 66 presently, which I believe to be original but can't proove it, SHOULD BE 3/4". IF it is 7/8", it is either a 69-82 version, transplanted, OR, a SERVICE REPLACEMENT per your post for the 63-68 cars. I don't honestly know at the moment what size it is, but it is manual. Thx again, if I want to ensure judging correctness of the power steering (maybe someday but no time soon) I would need a 3/4" power steering rod. Thx!....Craig

[Joe L.]

Re: 65 Relay Rod diameter??

Craig-----

I can almost guarantee that the power steering relay rod which you acquired with the kit will be the 7/8" OD rod; the 3/4" rod hasn't been available from GM in 33 years.

As far as the 65-68 big block rod goes, I EXPECT that the original was a 3/4" OD rod, but I don't know that for certain. As I mentioned, how it otherwise differs from the small block rod, I don't know. If you have it off the car, I could use some good pictures of it. Perhaps, I'll be able to discern the differences from these.

[Craig S.]

Re: 65 Relay Rod diameter??

Thx Joe...when I pull the rod from the car, I will take some pictures. Craig