Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > Porsche 911 Technical Forum

Reply
 
LinkBack Thread Tools Rating: Thread Rating: 3 votes, 5.00 average.
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Mar 2002
Location: New Hartford, NY
Posts: 700
rubber a-arm bushing question

Hi, are the stock rubber bushings on the a-arms pressed on by the factory or vulcanized(bonded) on? Anyone know for sure? Thanks, Jerry
Old 02-15-2006, 06:45 PM
  Pelican Parts Technical Article Directory    Reply With Quote #1 (permalink)
Somewhere in the Midwest
 
MotoSook's Avatar
 
Join Date: Oct 2001
Location: In the barn!
Posts: 12,451
There seems to be a debate as to whether the vulcanize in place is a myth. Either way (bonded or otherwise), you will have to buy new A-arms or send your A-arms off to get fitted with new rubber bushings. Either is spendy, something like $400+

Check out the polygrahphite thread currently active or search the archives for all the alternatives.
Old 02-15-2006, 06:49 PM
  Pelican Parts Technical Article Directory    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Mar 2002
Location: New Hartford, NY
Posts: 700
I was told by Smart Racing that they press fit new rubber bushings on the a-arms and they were not vulcanized on by the factory. I am considering this option but still have not made my mind up yet. My other option will probably be poly-bronze. My car is strickly street, so I am very concerned with ride quality, Jerry
Old 02-16-2006, 07:14 PM
  Pelican Parts Technical Article Directory    Reply With Quote #3 (permalink)
Information Junky
 
island911's Avatar
 
Join Date: Mar 2001
Location: an island, upper left coast, USA
Posts: 41,006
Quote:
Originally posted by Souk
There seems to be a debate as to whether the vulcanize in place is a myth. .. .
debate!? The only one I know contesting the "vulcanized in place" /thinks it's a myth, is that trouble maker island911.





Sooo . ...This thread got me to go take some pix for you myth believers.







Shown horizontally here, the mold parting line gives away the tooling process.

IF the rubber where "vulcanized (cast/molded) in place" we would see a couple vertical parting lines. (else you could not remove the mold)

Also, fwiw, the rusty claw marks, above, are from where I grabbed the thing with some giant channel-locks to twist until it slipped. (not stuck to the shaft)
__________________
Everyone you meet knows something you don't. - - - and a whole bunch of crap that is wrong.
Disclaimer: the above was 2 worth.
More information is available as my professional opinion, which is provided for an exorbitant fee.

Last edited by island911; 02-16-2006 at 09:39 PM..
Old 02-16-2006, 09:25 PM
  Pelican Parts Technical Article Directory    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Mar 2004
Location: New Jersey
Posts: 1,861
Island..I like the logic that they are not bonded in place. But I can't help but wonder why the factory [or anyone for that matter] doesn't offer rubber replacement bushings?? They have to be easier to install the the poly's and we know they last longer??
__________________
Peace, Ron
www.ronorlando.net
78SC Targa 3.2 SS, 964 cams, CIS, SSI's,Dansk
Own a gun and you can rob a bank , own a bank and you can rob the world.

Last edited by Mysterytrain; 02-17-2006 at 07:11 AM..
Old 02-17-2006, 05:05 AM
  Pelican Parts Technical Article Directory    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Aug 2002
Location: Orchard Park, NY
Posts: 10,521
I think we should start using proper terms here.... "vulcanizing" is simply the manufacturiing/curing process of the rubber molecules themselves, right?...I think we're debating whether or not the rubber is "bonded" to the steel pilot shaft of the A-arm...or is it a "press-fit"..?

Nothin' to do with the molecular change that the material undergoes in the "vulcanizing" process....no ?

-Wil
__________________
Wil Ferch
85 Carrera ( gone, but not forgotten )
Old 02-17-2006, 05:35 AM
  Pelican Parts Technical Article Directory    Reply With Quote #6 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Somewhere in the Midwest
 
MotoSook's Avatar
 
Join Date: Oct 2001
Location: In the barn!
Posts: 12,451
Perhaps the reason rubber replacements are not available is the need to press them in. I imagine that the rubber bushings need to be compressed considerably to perform well. That is, if there is not enough compression of the rubber, they will go loose in a fairly short amount of time.

Damn trouble makers! WTF..why don't you just settle for myths and bad information so we can get on with our lives

Last edited by MotoSook; 02-17-2006 at 07:00 AM..
Old 02-17-2006, 06:21 AM
  Pelican Parts Technical Article Directory    Reply With Quote #7 (permalink)
Information Junky
 
island911's Avatar
 
Join Date: Mar 2001
Location: an island, upper left coast, USA
Posts: 41,006
Apparently, getting the rubber bushings to press in often causes shop rage . .. .loudly muttered split infinitives, tools in high velocity thru the air. . . tramatic flashbacks to the first discovery that "made in China" condoms are NOT going to work.

Okay, seriously . .. Roland, wayback, pointed out that Porsche was concerned about keeping the bushings sealed tightly. (apparently roads have dirt and grit on them sometimes -Capt Obvious)

So, I see two ways to seal these. One, chemically bond; two, physically constrain. For various reasons, I believe that Porsche chose to physically constrain these.

Now, just because they go on "pressed" does not mean that no bonding takes place. It's a funny thing, adhesion . .. ya press a piece of rubber against a piece of clean steel for 10 or 20 years, and guess what?

Of note; the very old a-arm I have to play with is fairly concentric (read: no 20years of loading) .... the bushing will stick to the center shaft for ~15 of rotation. It then breaks loose, and drags, slowly, smoothly, arounfd the center.

I believe this slipping to be part of the genius of the design. YMMV
__________________
Everyone you meet knows something you don't. - - - and a whole bunch of crap that is wrong.
Disclaimer: the above was 2 worth.
More information is available as my professional opinion, which is provided for an exorbitant fee.

Last edited by island911; 02-17-2006 at 08:19 AM..
Old 02-17-2006, 08:17 AM
  Pelican Parts Technical Article Directory    Reply With Quote #8 (permalink)
Wider is Better
 
wholberg's Avatar
 
Join Date: Jan 2005
Location: Apex, North Carolina
Posts: 1,056
Garage
Quote:
Originally posted by island911
Apparently, getting the rubber bushings to press in often causes shop rage . .. .loudly muttered split infinitives, tools in high velocity thru the air. . .
Pressing an oversize rubber bushing into a metal tube will always be frustrating. This is why american cars use rubber bushings with inner and outer steel sleeves, to facilitate pressing in of the bushing, and to enable rotation inside the bushing.

Would it be practical to make rubber bushings for older Porsches with this construction?
__________________
Wider is Better
Old 02-17-2006, 08:58 AM
  Pelican Parts Technical Article Directory    Reply With Quote #9 (permalink)
Information Junky
 
island911's Avatar
 
Join Date: Mar 2001
Location: an island, upper left coast, USA
Posts: 41,006
no descent?
__________________
Everyone you meet knows something you don't. - - - and a whole bunch of crap that is wrong.
Disclaimer: the above was 2 worth.
More information is available as my professional opinion, which is provided for an exorbitant fee.
Old 03-06-2006, 10:58 AM
  Pelican Parts Technical Article Directory    Reply With Quote #10 (permalink)
Registered User
 
Join Date: Mar 2004
Location: New Jersey
Posts: 1,861
Nah, not me. I'm dreaming about someone selling these rubber bushings. Me boiling them in water and then pressing them onto my powder coated control arms.
__________________
Peace, Ron
www.ronorlando.net
78SC Targa 3.2 SS, 964 cams, CIS, SSI's,Dansk
Own a gun and you can rob a bank , own a bank and you can rob the world.
Old 03-07-2006, 07:16 AM
  Pelican Parts Technical Article Directory    Reply With Quote #11 (permalink)
Registered User
 
Join Date: Apr 2003
Location: California
Posts: 1,266
In response to this topic raised a couple weeks ago on this forum, our company has started work on having these manufactured. We have secured a couple of new factory control arms to provide samples of these bushings for analysis and reproduction. They will be produced with the same rubber compound as the originals. I'll post info as soon as we have some idea of when these will be available, but this type of project generally takes 4-6 months before stock is availabe for sale. We do not sell direct to the public but our products will sold through retail companies like Pelican Parts if they decide to carry them. Be patient they are coming.
Old 03-07-2006, 07:30 AM
  Pelican Parts Technical Article Directory    Reply With Quote #12 (permalink)
Somewhere in the Midwest
 
MotoSook's Avatar
 
Join Date: Oct 2001
Location: In the barn!
Posts: 12,451
How will you address the installation?
Old 03-07-2006, 07:32 AM
  Pelican Parts Technical Article Directory    Reply With Quote #13 (permalink)
Registered User
 
Join Date: Aug 2004
Location: Grand Rapids, MI
Posts: 2,678
Garage
I just installed some front poly bushings manufactured by Daystar, they were an outstanding fit, and pressed right on by hand once the proper Weltmeister lube was applied. I haven't installed the A-arms yet so I can't speak to ride quality, but I have heard the fit of the Weltmeister bushings requires some "massaging" to get them to work properly.
__________________
Michael
Sans Porsche...for now
2009 Mazdaspeed 3 Grand Touring daily driver / DS autocross toy
2010 Subaru Forester X Limited - wife's daily driver
Old 03-07-2006, 08:23 AM
  Pelican Parts Technical Article Directory    Reply With Quote #14 (permalink)
Registered User
 
Join Date: Aug 2002
Location: Orchard Park, NY
Posts: 10,521
AFAIK...all of the plastic type replacement bushings will either require...or benefit greatly from.... a custom fit ( turning to a specific ID and OD ).

The problem is that you can measure and fit the ID of the bushing to the male portion of the A-arm... but once you install the A-arm, the outer "hold-down" part clamps on the OD of the bushing and distorts the precious fit you *thought* you had for the ID. Best to test fit and true the ID on the A-arm while somehow mimic-ing the clamping action of the outer, hold-down piece.

- Wil
__________________
Wil Ferch
85 Carrera ( gone, but not forgotten )
Old 03-07-2006, 06:17 PM
  Pelican Parts Technical Article Directory    Reply With Quote #15 (permalink)
Registered User
 
Join Date: Aug 2004
Location: Grand Rapids, MI
Posts: 2,678
Garage
FWIW Wil, We installed the rear clamps on the OD of the bushing and they fit very well. We pressed one on by hand, the other we used a shop press to finish pressing it, but it didn't take much.
__________________
Michael
Sans Porsche...for now
2009 Mazdaspeed 3 Grand Touring daily driver / DS autocross toy
2010 Subaru Forester X Limited - wife's daily driver
Old 03-07-2006, 06:41 PM
  Pelican Parts Technical Article Directory    Reply With Quote #16 (permalink)
Registered User
 
jpahemi's Avatar
 
Join Date: Feb 2004
Location: Long Island, N.Y.
Posts: 1,798
aturboman:
Will you be selling the bushings or the complete arm? Will you be manufacturing your own arm or refurbishing them?
j.p.
Old 03-07-2006, 07:11 PM
  Pelican Parts Technical Article Directory    Reply With Quote #17 (permalink)
Registered User
 
Join Date: Apr 2003
Location: California
Posts: 1,266
We are a parts manufacturing company so we do not get involved on the repair or installation side. The bushings will be offered to our wholesale customers and they will determine the best way to retail them. I suspect they will be offered for sale individually, but should be replaced in sets like all the other aftermarket versions currently for sale. I'm working on these at full speed so thanks for the interest.
Old 03-07-2006, 07:23 PM
  Pelican Parts Technical Article Directory    Reply With Quote #18 (permalink)
Registered User
 
randywebb's Avatar
 
Join Date: Nov 2004
Location: Greater Metropolitan Nimrod, Oregun
Posts: 10,043
This is great news!
__________________
"A man with his priorities so far out of whack doesn't deserve such a fine automobile."

- Ferris Bueller's Day Off
Old 03-07-2006, 08:02 PM
  Pelican Parts Technical Article Directory    Reply With Quote #19 (permalink)
Recreational User
 
porschenut's Avatar
 
Join Date: Mar 2004
Location: A Mile High
Posts: 3,897
I'm glad I decided to postpone my bushing replacement project! aturboman, you are answering a lot of people's prayers. I predict they will be a best selling item.
__________________
Dave
'88 Carrera CE Coupe
'86 coupe, '86 targa, 993 coupe, 997S coupe, 928 (all gone)
Old 03-08-2006, 07:13 AM
  Pelican Parts Technical Article Directory    Reply With Quote #20 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 09:05 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2016 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.