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Rubber vs polyurethane suspension bushings

partsloco

Sr. Member
Joined
Jun 15, 2004
Messages
405
I'm replacing the bushings in my shackles and cannot decide to go poly or rubber. I have a complete rear leaf and shackle poly kit from Toms already. I'm leaning towards rubber because it adsorbs road impact better then poly. Early broncos are notorious for rear cabin noise and squeaks. I already have the tailgate silencer kit. let know what you guys think. This bronco is on the road 99% of the time.

https://youtu.be/vdOdeDGbaIc


If you guys want to see the install

Part1

https://www.youtube.com/watch?v=Rr2KQ1Asx1Y

Part2

https://www.youtube.com/watch?v=Dq6Be-w6ORk

Part 3

https://www.youtube.com/watch?v=9x03RGJYOqc
 
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bknbronco

Bronco Guru
Joined
Jan 17, 2011
Messages
4,378
Loc.
North Metro, MN
i too had poly bushings ready to be installed but my spring packs came with rubber already installed so i bought new rubber shackle bushings as well. Rubber "C" bushings. Rubber radius arm bushings.

Years ago i had a little sami and put poly bushings in the leaf springs and it creeked bad all the time....from that day forward i swore to never use poly if rubber is available
 

McLeod

Full Member
Joined
Jun 29, 2008
Messages
296
Poly bushing need to be lubed with silicone grease or they will squeak.

I buy the grease by the tub. It is the most obnoxious stuff you will ever get on your hands.
 

WILDHORSES

Sponsor/Vendor
Bronco Guru
Joined
Nov 7, 2003
Messages
2,196
Loc.
USA
Back in the day I was sold on rubber for the rear springs and shackles. Over the years I have switched to well greased poly bushings. The outer lips on the poly bushings keep the springs from offsetting to one side. I think for a street rig you are fine either way but for off road I'm urethane all the way.

Jim
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
8,614
As previously mentioned, use the poly lube...and it is nasty stuff but works great!!
 

ntsqd

heratic car camper
Joined
Jan 30, 2005
Messages
3,229
Loc.
Upper SoKA
A friend has told me for years that when (not if) poly bushings squeak they need to be replaced. Nothing you can do will stop them from squeaking, and it doesn't matter if they've got 10 feet or 100,000 miles on them. And that advice assumes that they were installed using the silicone grease.
 

toddz69

Sponsor/Vendor
Bronco Guru
Joined
Nov 28, 2001
Messages
10,080
At some point I'm going to do a hybrid of rubber and poly on my rear springs. The forward bushing is the 'ride' bushing so I'm going to go rubber there. Out back I'll go with well-lubed poly for a little more lateral stability. I read that Detroit Speed did this with their leaf spring builds and thought it sounded like a good idea.

Todd Z.
 
OP
OP
partsloco

partsloco

Sr. Member
Joined
Jun 15, 2004
Messages
405
I'm actually installing Poly. The Moog bushings I got from Oreilly's were too think in diameter. All websites say Moog K200923 is OE replacement. I have a press and they would not go in. I measured the old ones and they where about 29mm the moog's were around 31mm

Moog K200923
 
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nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
8,614
I ran poly bushings as SOON as they were available on EVERYTHING I could on my Bronco. I was replacing track bar bushings literally every 12 months or earlier. I went with poly and it lasted 3 years. Replaced with heim joints on the track bar after a lengthy debate on B-Fix (TS will remember this) and got just shy of 17 yrs...same abuse, just that high a quality (Performance Offroad). I could barely feel any wear in the heims- but figured new is cheaper than any potential breakage costs...

I ran poly front end bushings, spring eye bushings for over 20 years.... I replaced the front C bushings once, opposite end- 3 times as I experimented with lower durameter poly but they tore up quick... :)

Spring bushings lasted longer than each set of rear leaf spring packs, I averaged about 3-4 years per broken spring back...

What I'm saying here is the poly never squeaked...back in the early '90s I wasn't a big believer in lubing the poly as much as the past 20 years...

So in 10 years + on both sets of radius arm cap bushings...no squeaks from any poly bushing-lubed properly or not....maybe my experience only..........?
 
OP
OP
partsloco

partsloco

Sr. Member
Joined
Jun 15, 2004
Messages
405
I have poly on my track bar and C-bushings also. Have poly on my fox shocks too. Never had any noise I can tell. I should be done tomorrow. I hate doing the rear leaf springs. Already have about 5 hours in. This is the third time I've had the rear leafs out in 20 years. Every time was a nightmare pain in the ass.

First I had stock spring with blocks

Second I had the stock springs with add a leaf and smaller blocks

Third I put in these 3.5" lift springs

Fourth I replaced all the rear leaf and shackles with Poly

Hopefully this will last another 5-10 years.
 

ntsqd

heratic car camper
Joined
Jan 30, 2005
Messages
3,229
Loc.
Upper SoKA
Have I mentioned how much I dislike SRE's on street driven vehicles?

;)

Bronc-up as it is currently, nvrstk might recognize the color under the gray (get out your way-back machine & think magazine cover EB):
i-PgckJFn-L.jpg
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
8,614
HAHA! let's see...once or twice if I remember correctly!!

I had to shake loose some old gray matter to remember that old color! Yup... when is the anticipated "re-birth" of it rolling again?
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
8,614
Dangit Todd Z...you think outside the box :) and mixing those bushings sounds like a great idea...keep us in the loop when you get a chance to give us some feedback on that! Thx
 

toddz69

Sponsor/Vendor
Bronco Guru
Joined
Nov 28, 2001
Messages
10,080
Dangit Todd Z...you think outside the box :) and mixing those bushings sounds like a great idea...keep us in the loop when you get a chance to give us some feedback on that! Thx

Like most of my ideas, they come from someone else :). Will keep you posted.

Todd Z.
 

McLeod

Full Member
Joined
Jun 29, 2008
Messages
296
I think you need to revise your youtube links - they don't work for me
 

LUBr LuvR

Contributor
Bronco Guru
Joined
Dec 31, 2015
Messages
1,956
Think I know the answer to this one.....but the 7* C-bushings are only available in poly, right? Only been able to locate rubber in the stock 2* bushings.
 
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