Problem with new Strut Rod Bushings - are these ruined?

[Scott S.]

I used new GM 3775762 Strut Rod Bushings (1963-1974). Most of the rear suspension has not been tightened up and torqued yet. I was under the car Wednesday and noticed that the rubber in the strut rod bushings was pulled away (see pics below).

Did we do something that ruined these, or should they be fine when everything is torqued and the full weight of the car is on the suspension?

[Ronald L.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Scott, My thinking on this is that you will be OK once you set these and the car is on wheels.

Second you are seeing that inner sleeve because the originals had bonded in rubber. What I did was save that edge and "bond" it back on, even then with the wheels hanging, you get some of this look.

[Scott S.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Scott, My thinking on this is that you will be OK once you set these and the car is on wheels.

Second you are seeing that inner sleeve because the originals had bonded in rubber. What I did was save that edge and "bond" it back on, even then with the wheels hanging, you get some of this look.

Thanks Ron, that's good to hear!

Gene mentioned (in my other Thread) that my bushing end caps were missing. I have a set from Bairs, but looking at the pictures, how do they fit? It's a tight fit as it is, it doesn't look like there's any space for them between the end of the bushing and the strut rod bracket

[Joe L.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Thanks Ron, that's good to hear!

Gene mentioned (in my other Thread) that my bushing end caps were missing. I have a set from Bairs, but looking at the pictures, how do they fit? It's a tight fit as it is, it doesn't look like there's any space for them between the end of the bushing and the strut rod bracket

Scott-----


Caps were used on both sides of the bushings and the strut rods with bushing end caps WILL fit within the bracket.

[John H.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Gene mentioned (in my other Thread) that my bushing end caps were missing. I have a set from Bairs, but looking at the pictures, how do they fit? It's a tight fit as it is, it doesn't look like there's any space for them between the end of the bushing and the strut rod bracket

Scott -

As Joe noted, they WILL fit. Those hardened caps are an essential part of that system, as they hold the cam bolt centered in the bushing and allow the cam bolt to make (and hold) its adjustment; the I.D. of the inner sleeve in the bushing is larger than the O.D. of the bolt, and the O.D. of the bolt is a close-tolerance fit in the hole in the cap. The O.D. of the extruded collar on the cap (which the bolt fits through) is a close-tolerance fit in the ends of the bushing's inner sleeve. Don't even THINK about assembling it without the hardened caps.

[Alan D.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Scott a few pictures may help -
You will also need to look at C2 Strud Rod Bushings - which ones to use?
Note the washers of OEM v repop are different depending upon year which I think that same thread goes over.
Note even after torque the strut rod & insert will look twisted when back up on lift.

[Gene M.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Scott,
I guess I screwed up and answered this thread in your other one (brain freeze).

The GM replacement bushings are a bit different from the originals. Replacements have a steel sleeve the originals do not. I think they are an improvement over originals. Having the sleeve makes the rubber thinner thus more rigid.

They both should use the cup washers as John says. Having the washers in place will "straighten out" the positioning a bit also as it takes up space and fits everything nice and tight.

[Scott S.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Thanks to everyone for the replies, I will find the end caps and get them installed. If all else fails, it shouldn't be anything a hammer won't fix

[Paul L.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Scott -

As Joe noted, they WILL fit. Those hardened caps are an essential part of that system, as they hold the cam bolt centered in the bushing and allow the cam bolt to make (and hold) its adjustment; the I.D. of the inner sleeve in the bushing is larger than the O.D. of the bolt, and the O.D. of the bolt is a close-tolerance fit in the hole in the cap. The O.D. of the extruded collar on the cap (which the bolt fits through) is a close-tolerance fit in the ends of the bushing's inner sleeve. Don't even THINK about assembling it without the hardened caps.

Makes you wonder why the OD of the bolts does not match the ID of the bushing sleeve and the bolt appropriately lubed to move. Then the caps, and the pressure put on them, would not be necessary. The ends of the bushings could simply be protected by a round washer, inside the brackets, again lubed.

[Terry M.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Makes you wonder why the OD of the bolts does not match the ID of the bushing sleeve and the bolt appropriately lubed to move. Then the caps, and the pressure put on them, would not be necessary. The ends of the bushings could simply be protected by a round washer, inside the brackets, again lubed.

The sleeve is not supposed to rotate on the bolt -- therefor there is no reason to lube the bolt. Now anti-seize so they don't rust together is another matter -- if you ever intend to get them apart again.

I am not convinced that the service replacement strut rod bushings, without the outer sleeve, will ever function properly. Bushings of this type - outer sleeve, compressed and bonded rubber, and inner sleeve -- are designed so that the rubber will twist, or torque, between the two sleeves as the suspension moves. The inner sleeve should have teeth on it so that the inner sleeve will grip the stationary mounting point of the suspension when the suspension fastener is properly tightened and the outer sleeve should be a press fit into the moveable part of the suspension. Take away that outer sleeve, as is done with the service replacement strut rod bushings, and the only purpose that bushing serves is a isolator to prevent metal to metal contact. But then I might be missing something and someone needs to 'splain it to me.

[Alan D.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Terry - that's right.
Follow the link in my post #6 to additional info on Terry's comment. The GM replacement bushing is correct however the other generic repop is the bad choice.

[Terry M.]

Re: Problem with new Strut Rod Bushings - are these ruined?

If I read that linked thread right, the service replacement bushings are claimed to come with an outer sleeve. That is not my experience from several decades ago.

The original bushings on my 1979 have an outer sleeve.

[Dick W.]

Re: Problem with new Strut Rod Bushings - are these ruined?

If I read that linked thread right, the service replacement bushings are claimed to come with an outer sleeve. That is not my experience from several decades ago.

The original bushings on my 1979 have an outer sleeve.

All the bushing we purchase from Generous Motors had the steel sleeve on the outside. What a PITA to install.

[Gene M.]

Re: Problem with new Strut Rod Bushings - are these ruined?

If I read that linked thread right, the service replacement bushings are claimed to come with an outer sleeve. That is not my experience from several decades ago.

The original bushings on my 1979 have an outer sleeve.

Yes, Terry, with an outer sleeve with a GM tag/box (small loops strut arm). They were sold that way so they could be installed by owner. The originals without sleeve would be difficult to press at best.

And all good chassis judges look for the replacement in the mid years and 68 too (small loops). But I don't know about all the other c3's when the sleeve was cut in using the bigger strut rod loops. I'm quite sure the 79 would have the big loop strut rods ...... right?

[Joe L.]

Re: Problem with new Strut Rod Bushings - are these ruined?

Yes, Terry, with an outer sleeve with a GM tag/box (small loops strut arm). They were sold that way so they could be installed by owner. The originals without sleeve would be difficult to press at best.

And all good chassis judges look for the replacement in the mid years and 68 too (small loops). But I don't know about all the other c3's when the sleeve was cut in using the bigger strut rod loops. I'm quite sure the 79 would have the big loop strut rods ...... right?

Gene------

1963-74 Corvettes used the small end strut rods. These use bushings GM #3775762 which are 1-1/4" OD. 1975-82 Corvettes use the large end strut rods. The bushings are GM #3829519 which are 1-3/8" OD. Both of these bushings use a steel outer shell with the elastomer component vulcanized to that outer shell. They are manufactured by Clevite or Harris. The original strut rods had the bushings vulcanized to the strut rod, itself. So, no outer shell was needed.

There are "reproduction" bushings available which do not have an outer steel shell. These are designed to eliminate the possibility of any judge noting just the nuance you described. These bushings are an example of "form-over-function". I absolutely do not recommend the use of these bushings UNDER ANY CIRCUMSTANCES.