78 rear strut rod bushing problem

[David M.]

[Mark E.]

Re: 78 rear strut rod bushing problem

The bushing OD was increased from 1.2" to 1.39" beginning sometime around 1975.

[Michael W.]

Re: 78 rear strut rod bushing problem

Mark is correct.

Equally important to understand is that poly is the worst possible choice for bushing material in any spot where deflection in multiple axis is required. The old marketing claim that poly 'lasts longer' is also proving to be untrue in many cases.

[Joe L.]

Re: 78 rear strut rod bushing problem

The bushing OD was increased from 1.2" to 1.39" beginning sometime around 1975.

Mark-------


Yes, the 1963-74 strut rod bushings were 1-1/4" OD. the 1975-82 strut rod bushings were 1-3/8" OD. However, the 1975-79 strut rods were for many years SERVICE for 1963-74. The 1980-82 strut rods were unique to those years but still used the same 1-3/8" bushings as 75-79.

[Joe L.]

Re: 78 rear strut rod bushing problem

Here is a thread from another site I frequent. The guy has a 78 which he’s trying to replace the strut rod bushings with poly. They look way too small for the ID of the rod.

Here’s his quote;
“The rod that goes from diff to lower end of wheel spindle.
We are trying to replace the four rubber/ steel bushings in these two struts.
The rubber/inner steel sleeve assembly is WAY too big to press into the round steel strut end, and when you press on it the rubber bulges and makes it even less likely to insert.
We took out the inner steel sleeve from the rubber part, and then the rubber can be put into the outer sleeve aka strut end hole... but then the rubber part ID is like 1/4" smaller than the inner steel sleeve's OD, so no way is that going in either.
Tried looking on the internet for clues have not had time to ck the service manual yet, sorry [shame]

maybe someone here has done this already?

It appears that assembling the rear wheel bearings and shafts into the carriers also requires a press and specialty tools... oy. They use a spacer and selectable shim between the two bearings, like a pinion shaft if the diff, but the spacer is not collapsible.

Maybe we got the wrong bushings?”

Here is my reply:
“I suspect you have the wrong part. 63-79 has a 1.200 OD strut bushing. 80-82 has the 1.390 OD. You’re likely trying to stuff an 80-82 bushing in there. There is also (possibly) yet a third for the FE7 Gymkana suspension. That’s identified by the rear sway bar and 7 leaf spring and of course the tank sticker if you’re lucky enough to have one. Do you have an AIM manual? It’s listed there. I ran into this with Dads 68 small block. Then toss in the Big vs Small block rear ends in the early C3s....nother story”.

So now it looks like they want to install polys but they arent right either. Here are the pics of what he has. What do you guys think? Will this bushing compress to fit the hole or does he have something else going on here?

TX!
Dave

Dave------


Tell him to use strut rod bushings GM #3829519 for the 1978 and his problems will be over. These bushings are going to last longer than he's ever going to need them.