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Discussion Starter · #1 ·
I'm creating this thread to track my attempt to make bushings for the rear knuckles. So far I have ordered and received a 3"x2' polyurethane rod, durometer of 80. (Yes, it was expensive)
I'm waiting for the knuckles; the scrap yard I'm dealing with apparently is in no particular rush to get them out of the car. Kinda of like a lazy mans scrap yard. For the price, I'm willing to wait.
So, that's where I'm at.

"Urethane parts may have a wide range of hardness, from 20
Shore A durometer(rubber band) to 75 Shore D durometer
(Aluminum). Urethane has great impact resistance, with even
the hardest Urethanes, you have significantly better impact
resistance than plastics and composites. While conventional
plastic materials can become brittle as they become harder,
urethane retains elasticity and strength over the complete
range of hardness.
Hard durometer Urethanes compounds are easily drilled, tapped
and machined.Hard durometers Urethane parts are often used
in gears, cams, control mechanisms, and other applications.
Soft durometers compounds are commonly used to replace rubber
for improved sound/vibration dampening.
Urethane parts may be manufactured in elastic ranges between
250-1000 lbs/linear inch, and are far superior to natural
rubber in all applications. Therefore, Urethane may be used
for drive belts, seals, diaphragms, gaskets, and other
applications requiring strength and flexibility ."

This thread will probably go stale until I can get my stuff together, it could also prove to be a big waste of time.
 

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Discussion Starter · #2 ·
Finally got the knuckles today. $114.00 for both. They left on the hub/bearing assembly, what a pain to get those out. Literally, after beating with a hammer, it fliped off from the vise and ricocheted off my shin. First time was an accident, but almost did it the second time again. That would of confirmed I'm stupid. :)

Going to get them sand blasted and see what these "bushing housings" look like.
 

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Discussion Starter · #4 ·
Sandblasted the knuckles yesterday. Picked at the bushing to see if they actually press out, and they do.
I have some pictures but unfortunately, they all turned out blurry. If you feel like getting a headache:
http://yan.webhop.org/ids/index.cgi?mode=album&album=/Autos/knuckles

Curious how the bushing itself (the bolt sleeve) pivots. Not sure what purpose it serves and if replaceing with a non pivoting bushing, what will be the effect of...
^^anyone have any insights into that, it would be appreciated.
I do think however that a non pivoting bushing would be better than leaving it the way it is.

I have a company who has expressed interest in possibly making a bushings. but they need to see the part as well as measuments.
There answer will be the first clue if it's possible.
 

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Discussion Starter · #6 ·
I need a volunteer in the Coos Bay Oregon area. I found someone interest in pursuing this project.

If your interested send me an email. [email protected]
Here is a quote of his intentions; I predict 30-60 minutes.
"Just going to look. See how they work and how the suspension moves.
If it needs to move fore and aft or just up and down, etc.
No changing or damage."

BTW...If you folks have an interest in seeing an after market part of this nature, you might want to start posting your support here. As of now, it looks like he might have three sold. :)
 

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1997 Seville STS, Black
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Curious how the bushing itself (the bolt sleeve) pivots. Not sure what purpose it serves and if replaceing with a non pivoting bushing, what will be the effect of...
Same way the bushngs on the front suspension pivot, they dont.
The rubber just twists as the suspension moves up and down. Which is why they wear out.
With polyurethane bushings the sleeve actually DOES pivot inside the bushing material, which is why they will sometimes squeal without proper lubrication. Have the millshop cut out some "tracks" inside the center of the bushing paralele to the sleeve then apply grease inside the bushing when they are put on the car and it will help prevent squeaks.
 

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Discussion Starter · #13 · (Edited)
Thanks 97STS4ME....That's something to stongly consider, maybe even a grease nipple. But for clarification grease is not recommended on polyurethane bushings. But rather poly lube. But I get the idea.

After some research (google) Cross-axis ball joints assist in ride comfort. But obviously more questions need to be asked. I need to make sure that additional stress is not transfered to the control arms, hence causing a catastrophic failure.

I asked Mr. Millwirght to hold off until I know more about cross-axis ball joints...
 

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Kind of makes you wonder why they didnt just use regular balljoints like every other normal double wishbone suspension setup out there. I guess the rubber absorbs more vibration?
But for clarification grease is not recommended on polyurethane bushings. But rather poly lube. But I get the idea.
I was close enough to get my point across. :p
 

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Discussion Starter · #15 ·
From what I've found so far the 2000 Dodge prowler had rubber bushings in the rear and was changed out to cross axis ball joints. Here is a quote;

"Significant improvements for 2000 include enhanced overall ride characteristics. Engineers improved the two-seater's ride by reducing friction in the rear suspension. Specifically, rubber bushings were replaced with cross axis ball joints in the rear suspension lateral links. With reduced friction, engineers recalibrated the front and rear Koni shocks and reduced spring rates. The front spring rate is reduced 10 percent while the rear spring rate is reduced 20 percent for a smoother ride. "

I don't care about a smooth ride. If the rubber can be replaced by cross axis ball joints, then it's safe to presume it can also go the other way, as they did not make the change for safety but rather ride comfort.

Any thoughts on this?
 

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I have a 98 deville with a worn rear upper control arm bushing.

Has anybody come up with a way to replace the bushing without the entire $600 control arm yet? If all else fails, I'll just make some on my lathe out of aluminum. :)

I just can't justify spending $600 on a bushing for a car with 177,000 miles even if it is a Cadillac.
 

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I forgot to mention.... I searched for control arm bushings on Autozone.com and although they did not have them in their database yet, I got the impression that they may be coming up with a Duralast component soon. It's worth keeping an eye on their website just in case they start selling them soon.
 

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Discussion Starter · #18 ·
I forgot to mention.... I searched for control arm bushings on Autozone.com and although they did not have them in their database yet, I got the impression that they may be coming up with a Duralast component soon. It's worth keeping an eye on their website just in case they start selling them soon.
What gave you that impression?
If your going to make something up, I would not suggest aluminum or even brass for that matter, nylon wouldn't fair any better either. This is all in reguards to ware.
 

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How is this progressing? I have a set of spare knuckles. I tried pressing out the "bushing" with no success. I would be interested in making this work. This is a common problem on higher mileage cars.

By the way im in ontario too, Ottawa ;)
 

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Discussion Starter · #20 ·
JSMeloche,
They only come out in one direction, see these blurry pictures;
http://yan.webhop.org/album/main.php?g2_itemId=156&g2_page=2
Specfically pictures Picture 009 and Picture 010.
Notice the wall thickness, the thicker side is the side you apply force. Which would be Picture 009. I had to sweat mine out.
Hope that helps.
My Millwright friend is somewhat pre-occupied with life. I know he's working on it but, in his own time.

Hopes that helps, Good luck...
 
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