Polyurethane Bushings

Ralphy

Well-known member
Joined
Dec 12, 2009
Messages
537
I have been searching bushing materials. So far as what I have come up with there are many quality options for materials. However they all seem to be for race use only. Using something like delrin or nylon all have to high of a durometer rate for street use. They could elongate and damage parts.

Any how I found McMaster Carr sells polyurethane in bar form. From what I see 90 durometer looks like it would machine well and I think 90 is about what would be used. So if you have access to a shop, maybe check it out.

Look under rods, cords and discs.
http://www.mcmaster.com/#polyurethane/=dqa10t
 
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there's definitely different grades of quality..... here's a photo of my rear body mount (about 6 years old, maybe 5000 miles).

214d8143936059e.jpg

I would hope the material Mcmaster sells is better.
 
I remember that pic. It still amazes me how clean the fasteners and washers are vs. the urethane.
 
LOL

appearently the local hardware store sells some good quality stuff....

the poly mounts never even got wet, after i replaced the body mounts i painted the car in 2006, then replaced engine and trans in 2007... so it was basically not on the road for almost two years... I never drove it in the rain because my wipers dont work (except one time at Cocoa Beach in the thunderstorm of the century, Mike, Tim and Gene might remember)

anyways, due to their location these body mounts are not even exposed to the sun (UV)

i believe if you put these outside and expose to rain and sun they might not last a year :rofl:
 
I also noticed the load bearing side cracked. The lower side did not.
 
I was considering aluminum but I'm afraid instead of the bushing the body might crack... I'm convinced to go back to rubber.... little more flex but also protection for the body....

btw, when i installed these i had all eight mount bolts loose and shimmed until all eight mounts were tight (loaded), then i tightened the bolts.
 
On my '70 goat convertible, I had disc brakes, '80 caddy spindles, and Global West front suspension goodies...delrin/aluminum modified lower ball joint to fit the stock A arms....lasted well over 8 years daily driven....no issues, ever....

when I redid my rear body mounts here about ten years ago, I used the stock aluminum spacer....and filled/painted with heavy epoxy and paint it's ain't a gonna rust out in my lifetime anyway....

:crutches:
 
Kinda funny that my original body mounts on my 70 look better than your new ones.

Looking forward to seeing how it is done.

didn't the 70 come with aluminum mounts? i thought aluminum was used until 72 ??? when was the first year for rubber mounts ?
 
Kinda funny that my original body mounts on my 70 look better than your new ones.

Looking forward to seeing how it is done.

didn't the 70 come with aluminum mounts? i thought aluminum was used until 72 ??? when was the first year for rubber mounts ?

That would explain why they look better than yours:lol:

73 was first year for rubber mounts. They make poly mounts as replacements for 63 on up.
 
Why use poly for the body? I'm all for poly, I use poly and solid mounts everywhere. But for the body, I would stick with rubber. I would think it would be quieter and less prone to cracking.
 
It's pretty common, it seems, for repro elastomers to be of poor/punk quality. I bought some ball joints from one of the Florida vendors. After installing them, it was few years before I got the car on the road (my 68). The rubber boots had disintegrated. They had experience no road use, no ultraviolet radiation, nada. The original AC Delco boots had not deteriorated. (I couldn't use them since the ball joint/spindle removal tool tore the original boots.) Same comment about some other elastomer stuff. I have poly motor mounts on the 70. My 68 and 70 don't have elastomers in the body connect points.

Although, I know well there are some quality repro parts, in fact some of better quality than the original OEM stuff, I like to quote as a general rule about repro parts:


Hal's Law of Repro Parts:
(1) If it fits, it is of poor quality
(2) If it is of good quality, it won't fit.
............
The bold print was to make sure I didn't offend Dr. Rebuild with my statement of Hal's law.
 
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