C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

[William G.]

Greetings.

After reading the many postings on this subject I had decided to replace my original radius rods (choose the part name you prefer) with the Moog design which mimics, as I understand, it the later GM version ('75-'79) and is considered an improvement over the originals. Having received these parts from Fed Ex Friday I find that they do not fit my 1966 suspension. When adding the bushing caps (supplied with the Moog rods) to the Moog rods the assembly is some .080" to .090" (that is, each bushing cap is approximately .040 to .045" wider than the original small, 1966 pieces) too wide to fit the '66 carrier support bracket or the eared ends of the spindle support. Hence a few questions:

1. Are the '75 to '79 brackets and spindle supports wider than the earlier units?
2. If, as I suspect, the above is not the case has anyone else had to resolve this situation and how? My local Chevrolet parts department says that the bearing caps the factory used with the '75 to '79 strut rods [Joe Lucia, I believe, has posted a comment that the GM part number for these caps is (was) 348390] is no longer available. I'm thinking the number with only six digits long seems to be incorrect? The parts man had no interest in trying to help with a vehicle this old, in any case.
3. Would using the small, original bushing caps be an option? I should mention that the caps supplied by Moog are about .125" wide (without the inner "shoulder") and the originals about .090".
4. I could, perhaps, attempt to modify the Moog caps but there certainly has to be a better solution.
5. Anyone have contact information for Moog itself? The best solution would be for them to resolve this matter. Complicating this issue is that Moog may not have supplied the bearing caps themselves but, then, they did come packaged inside the Moog box. The major diameter of these (chrome plated) bushings is just short of 1.400", whereas I believe (as with the earlier part number) that Joe L. supplied a dimension of 1.320" for these '75-'79 items a few years back. The '66 originals are significantly smaller in diameter at about 1.100"

The Moog strut rods, dimensionally, are the same width end to end of the serrated inner sleeves as the original bushings.

Help................please. I can't be the only one with this issue. What am I missing? Something obvious? Of course, the comment regarding the outer end of the strut rod fitting in the gap between the eared ends of the spindle support is irrelevant!

Bill

[Bob R.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

William,
Try calling Bair's Corvette, they sell just about all of the parts used in a Corvette rear suspension and can probably answer your questions (814-683-4223)

[Duke W.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

It's always better to use original parts if they can be rebuilt/restored to original condition. GM never sold strut rod bushings, only the complete strut rod with bushings that ended up being the C3 strut rods that have bigger ID "eyes", but IIRC you can buy bushing assemblies that fit C2 strut rods, but it may require special tools to install them. Maybe someone else can provide more detail.

Duke

[Joe L.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

It's always better to use original parts if they can be rebuilt/restored to original condition. GM never sold strut rod bushings, only the complete strut rod with bushings that ended up being the C3 strut rods that have bigger ID "eyes", but IIRC you can buy bushing assemblies that fit C2 strut rods, but it may require special tools to install them. Maybe someone else can provide more detail.

Duke

Duke------

GM did and continues to supply strut rod bushings, both the 63-74 and 75-79 style. GM no longer SERVICES the strut rods, themselves.

[Joe L.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

Greetings.

After reading the many postings on this subject I had decided to replace my original radius rods (choose the part name you prefer) with the Moog design which mimics, as I understand, it the later GM version ('75-'79) and is considered an improvement over the originals. Having received these parts from Fed Ex Friday I find that they do not fit my 1966 suspension. When adding the bushing caps (supplied with the Moog rods) to the Moog rods the assembly is some .080" to .090" (that is, each bushing cap is approximately .040 to .045" wider than the original small, 1966 pieces) too wide to fit the '66 carrier support bracket or the eared ends of the spindle support. Hence a few questions:

1. Are the '75 to '79 brackets and spindle supports wider than the earlier units?
2. If, as I suspect, the above is not the case has anyone else had to resolve this situation and how? My local Chevrolet parts department says that the bearing caps the factory used with the '75 to '79 strut rods [Joe Lucia, I believe, has posted a comment that the GM part number for these caps is (was) 348390] is no longer available. I'm thinking the number with only six digits long seems to be incorrect? The parts man had no interest in trying to help with a vehicle this old, in any case.
3. Would using the small, original bushing caps be an option? I should mention that the caps supplied by Moog are about .125" wide (without the inner "shoulder") and the originals about .090".
4. I could, perhaps, attempt to modify the Moog caps but there certainly has to be a better solution.
5. Anyone have contact information for Moog itself? The best solution would be for them to resolve this matter. Complicating this issue is that Moog may not have supplied the bearing caps themselves but, then, they did come packaged inside the Moog box. The major diameter of these (chrome plated) bushings is just short of 1.400", whereas I believe (as with the earlier part number) that Joe L. supplied a dimension of 1.320" for these '75-'79 items a few years back. The '66 originals are significantly smaller in diameter at about 1.100"

The Moog strut rods, dimensionally, are the same width end to end of the serrated inner sleeves as the original bushings.

Help................please. I can't be the only one with this issue. What am I missing? Something obvious? Of course, the comment regarding the outer end of the strut rod fitting in the gap between the eared ends of the spindle support is irrelevant!

Bill

Bill-------


The 75-79 strut rod bracket and spindle supports are not wider than 63-67 or 68-74.

GM #348930 is the correct part number for the 75-79 caps. Many 1973-79 Corvette parts were 6 digit part numbers.

[William G.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

Joe,
Thanks a million. I will hit up another Chevrolet dealer's parts counter and refuse to leave until I get a satisfactory answer. I am most reluctant to use the smaller C2 caps on the larger, late 70s style bushing and even more reluctant to attempt to modify the caps supplied with the Moog struts. Duke, I also would prefer to stick with original factory components, however one of my original struts has an "eyed" end which is noticeable egg shaped (perhaps the camber bolt worked loose at some point?.........when one is pushing 79 it is a little difficult to get to those camber bolts to tighten with the weight on the car!) and I don't see where any of the after market "early" strut rod replacements can be trusted for quality--and Moog seems to have a pretty good reputation and the additional rubber of the larger rod is is, in my opinion, welcome. Thanks again, Joe. And kudos to all replies!

Bill

[William G.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

Greetings,

Well................I hope to not make this subject go on forever but here is what I have learned today. A second Chevrolet dealership told me this afternoon that, indeed, part number 348390 (that is the correct number) is "discontinued". Quite recently, it appears, since Joe L. is still of the opinion that "it is a good number". So I again called an 800 number I have for a tech line. Moog, and apparently, quite a few other companies. has gone together to form a tech line service. This man delved into my problem deep enough to come up with a copy of an old Chevrolet engineering drawing giving the specs Moog apparently has used to have these bushing caps manufactured. The o. d. is given as 1.375" and the thickness .125" w/o the "interior shoulder". These measurements are just what my Moog supplied caps measure. So, kind of a dead end. Unfortunately. This tech line individual said that this drawing has a 1980 date on it and hence I immediately told him that Chevrolet redesigned these spindle support rods again for the 1980-'82 models. This fact did not impress him (it SHOULD have), given that what we want for these C2 and C3s through 1979 ONLY is NOT marketed to fit 80-82 models! I have again taken a measurement with original spindle support rods and caps and compared this measurement to the Moog rods and "new style" caps. Side to side the original bushing and "end" caps measure 1.640" and the Moog comparable parts 1.685"..........a somewhat smaller difference than what I had reported earlier but still hardly usable at 1.685". Now these bushing caps, on the side up against the diff racket, are shaped convex, both on the small 63-74 bushings and on the caps that Moog supplied with my recently purchased spindle support rods. I could (carefully) grind these caps down about .020", however this would destroy the convex nature of the caps..............which certainly is there for a reason. So, this is very perplexing (to me at least). Why haven't others run into this? I could reuse the original caps but they are rather "wimpy" in comparison to the "Moog style"..........even after grinding the latter to fit the interior of the bracket.

Bill

[Gary B.]

348390

Gary

[Patrick H.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

I'm not sure why the insistence on the larger strut rod bushings?
Yes, they may be marginally better, but the smaller ones are definitely not obsolete or useless. Hundreds of thousands of Corvettes had them, with most that are in service still using the smaller design strut rod.

Unless you are regularly autocrossing or tracking your car, is there something else you expect to gain from them?

[William G.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

I'm certainly not insisting. however the original bushings appear to me to be far from durable and have, I should think, precious little rubber given all the flex the bushing must stand when the suspension is at full droop--this convinced me to look elsewhere. And the later design has somewhat more rubber. Since one of my strut rods needs replacing and GM, not surprising after all these years, no longer has them available and given I know of no source for used rods I'm kind of forced to aftermarket. Moog has a good reputation and as I couldn't distinguish a good used rod as opposed to inferior new or used I'm a little uncertain as to how else to proceed. At my age I certainly do not auto cross. Just trying (hoping, actually) to get this car back on the road for a little summer fun.

I'm probably a fool but I'm going to keep trying and perhaps my "luck" will change. Someone suggested Bair's and I may give them a call tomorrow but I don't imagine they deal much in used parts. Someone could pass off a used inferior rod on me and I couldn't tell the difference. Except for that I'd be willing to give Patrick's suggestion a try and attempt to save the originals.

Thanks for the thoughts..............this problem CAN'T be that difficult! I'm making it that! Apparently no one else has this problem with Moog struts..............except for that fact I'd be sure to report my ultimate cure.

[Joe L.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

I'm not sure why the insistence on the larger strut rod bushings?
Yes, they may be marginally better, but the smaller ones are definitely not obsolete or useless. Hundreds of thousands of Corvettes had them, with most that are in service still using the smaller design strut rod.

Unless you are regularly autocrossing or tracking your car, is there something else you expect to gain from them?

Patrick-------


I can offer this:

The original strut rods on my 1969 were, of course, the 1-1/4" type. Within only 5 or 6 years the rubber bushing were distorted to the point that the camber cam bolts and shock mounts had, essentially, pulled themselves through the rubber bushing and, essentially resided against the strut rod bushing orifices. This resulted in the "necessity" according to my Chevrolet dealer service department to bend the strut rods in order to achieve proper camber (bending effectively shortens the rods and "makes up for" the effective elongation caused by the above referenced bushing deterioration. Many 1963-74 Corvettes have had their strut rods bent by alignment servicemen for the same reason(it's easier and cheaper than replacing the bushings).

Many years ago I changed to the 75+ style 1-3/8" bushing rods. These were then GM SERVICE for 1963-74 and I reasoned that GM must have had a good reason for changing the size. These vulcanized-in-place bushings were installed on my car for MANY years. The above-referenced bushing problem never recurred with these and the camber bolts and shock mount shafts remained absolutely centered in the bushings.

I've never been able to figure out why the slight bushing enlargement solved the problem I experienced with the original rods and bushings but it did.

[Patrick H.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

Patrick-------


I can offer this:

The original strut rods on my 1969 were, of course, the 1-1/4" type. Within only 5 or 6 years the rubber bushing were distorted to the point that the camber cam bolts and shock mounts had, essentially, pulled themselves through the rubber bushing and, essentially resided against the strut rod bushing orifices. This resulted in the "necessity" according to my Chevrolet dealer service department to bend the strut rods in order to achieve proper camber (bending effectively shortens the rods and "makes up for" the effective elongation caused by the above referenced bushing deterioration. Many 1963-74 Corvettes have had their strut rods bent by alignment servicemen for the same reason(it's easier and cheaper than replacing the bushings).

Many years ago I changed to the 75+ style 1-3/8" bushing rods. These were then GM SERVICE for 1963-74 and I reasoned that GM must have had a good reason for changing the size. These vulcanized-in-place bushings were installed on my car for MANY years. The above-referenced bushing problem never recurred with these and the camber bolts and shock mount shafts remained absolutely centered in the bushings.

I've never been able to figure out why the slight bushing enlargement solved the problem I experienced with the original rods and bushings but it did.

I'll bet you didn't have the same issue with installation that William is, though.

I know the larger ones have been installed on plenty of Corvettes.
My suspicion is that the Moog parts he is attempting to install aren't the same dimensions as the originals, and caps won't work with them. That's the way it is with the 65 currently on my lift. They're too thick to use the caps.

He may need to look at alternate sources and/or reproductions of the small bushing units.

[Joe L.]

Re: C2/C3 Strut Rod/Camber/Rod/Spindle Support Rod

I'll bet you didn't have the same issue with installation that William is, though.

I know the larger ones have been installed on plenty of Corvettes.
My suspicion is that the Moog parts he is attempting to install aren't the same dimensions as the originals, and caps won't work with them. That's the way it is with the 65 currently on my lift. They're too thick to use the caps.

He may need to look at alternate sources and/or reproductions of the small bushing units.

Patrick------


No, I did not have that problem. I used new GM 1975-79 strut rods and the GM caps designed for them.