[urq] Subframes bushings r&R procedure

[Louis-Alain_Richard at computerhorizons.com]

You are probably right: the alu bushings have probably a good corrosion 
resistance, but what I am reffering to is "galvanic corrosion".
That is, when 2 parts of different metal are in contact together, the 
lesser one (in the glavanic corosion chart) will gradually destroy itself 
to protect the higher one if placed in an aggressive environment.

I know this is highly theorical, but my experience with the aluminum 
bumper supports (early GM full-size cars) under the chrome bumpers tell me 
that indeed galvanic corrosion exists. Or try to pop-rivet a sheetmetal 
floorboard with alu rivets; 2 winters and the rivets are loose...

In this case, the alu bushing is the "sacrificial anode" between the steel 
subframe and the steel chassis (exactly like the bumper support). 
I know this problem will not show until many years from now, but I am sure 
it will.
This explanation is for the rational side of myself.:-)

For the other side of my brain (the irrational): unlike many of you, who 
would install improved or upgraded parts, I like the feeling of driving a 
car "in its juice", with all the shortcomings typical of it's era. As an 
example: If I buy an older MGA, and I want to do historic rallies with it, 
I will do it the hard way, with drum brakes, no top, no windshield, open 
exhaust and bias-ply tires.

Call me a dreamer...

Louis-Alain






Bob <bob at audisport.com> 
2004-09-24 11:21

To
Martin at quattro.ca
cc
Louis-Alain_Richard at computerhorizons.com, urq at audifans.com
Subject
Re: [urq] Subframes bushings r&R procedure






Actually the ones I got were an alloy and arent supposed to corrode (but 
we will just see about that this winter!)
Bob

Martin Pajak wrote:

>Louis-Alain,
>
>I can't agree with you on this one...
>Rubber will deteriorate much quicker in salt than aluminium... also, if 
you get the aluminium anodised you should have no corrosion problems.
>
>Again, there is no harshness... remember I live in Toronto... I've been 
to Montreal and your roads are no worse then ours...
>
>Anyhoo... your choice.
>
>Cheers
>Martin
>---------- Original Message ----------------------------------
>From: Louis-Alain_Richard at computerhorizons.com
>Date:  Fri, 24 Sep 2004 10:16:43 -0400
>
> 
>
>>Thanks Martin and Bob, but I will stick to the OEM rubber bushings, for 
>>two reasons:
>>- corrosion (my car is winter driven, aren't Quattro the "King of the 
>>snow"?). IMO, alu and steel are not compatible in a salty 
environnement...
>>- harshness, even if everybody say that I won't know the difference, I 
>>live in Montreal, a city where the roads make Bagdad's look like a 
>>racetrack...
>>
>>Since I am going to France tomorrow, I will take the offer from Ado and 
>>grab a set from him.
>>
>>Thanks anyway,
>>
>>Louis-Alain