[flash]

if it's truly magnesium, it will be hard. if it's an aluminum alloy, it should be pretty easy. once i see a pic, i may have an idea. then i'll just need to get my hands on one.

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[MB968]

I'm fairly certain the old one is magnesium by the looks of the corrosion. Aluminum wouldn't do what I've seen on two different parts now. I have some drilling chips that I intend to burn to confirm it is magnesium. And, I understood from Porsche that the new part (-08, -09) is made from aluminum.

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[flash]

tracking what they did with this car is a bit like being an archeologist. the torque tube thing is making me a bit nuts. have a problem, come up with a fix. then delete the fix. no problem noted. was it there at all? why did they fix it? why did they think it didn't need to be fixed later?



this thing is the same kind of thing. make a part. discover a problem. come up with a better part. then delete that part. did they think the problem would go away by itself? did they think they had fixed all of the ones out there? did they think that magnesium would somehow stop corroding?

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[MB968]

I hear ya. I was pretty p....d when I found my bad part and found out is was going to cost ME close to a grand to fix. Just before my final retirement, I was Director of Quality for fair sized company. I think the Pres./Chairman would have dipped me repeatedly in one of the heat treat furnaces if I'd let something like this gone unanswered. Doesn't build confidence does it.

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[TonD]

Sorry for my ignorance, but as a non-native English speaker, I have some trouble grasping *what* part(s) are you guys actually talking about that are seemingly notorious for corrosion or falling apart? I've never heard such stories before (which in itself means nothing, but I'm just curious if I'm missing something).

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[tamathumper]

We're talking about the parts marked "Toothed Belt Covering" in this diagram:



http://www.autoatlanta.com/porsche-parts...103-05.php

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[flash]

i've now found out that this is almost entirely an east coast phenomenon

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[tamathumper]

Mine were removed and/or inspected last week and are in near perfect condition.

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[Cloud9...68]

[quote name='flash' timestamp='1335921249' post='126344']

i've now found out that this is almost entirely an east coast phenomenon

[/quote]

Didn't Silvy (who lives in Seattle, I believe) also report on this problem? Although it makes sense that the east coast is where most of the problems with there pieces would be.

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[flash]

my guess is that cars that have it that are not on the east coast, spent time on the east coast with a previous owner

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[Cloud9...68]

Could be. My data point is that my car spent its whole life in the south, and the distributor covers are nicely intact, except for the threads, which I had to heli-coil. Nice and snug now.

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[MB968]

My car was in Calif. most of it's life, then some years in Vanc. B.C., before coming to Portland. No east coast connection.

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[tamathumper]

Most likely a road salt connection, regardless of coast.

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[flash]

no salt here - never saw salt on the roads until i visited back east - didn't even hear about it until i started collecting cars



here's something of interest:



http://www.hindawi.com/journals/ijc/2010/602342/

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[tamathumper]

You'll only find salt where you find snow and ice - on your coast I'm certain that's a few miles north of where you live, but Seattle/Vancouver and north might see it? <img src="/forum/images/smilies/968/wink.png" class="smilie" alt="" /> Having reviewed my paperwork my car was originally in Virginia then moved to the west coast for a long time then back to Maryland, so that's probably why it's in such great shape.



My apologies - you'll also find salt if you drive on or near the beach and get sprayed with sea water. That was common growing up as a lobster fisherman and clam digger, but I didn't figure any of you would fall into those circumstance very often, if at all.

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[MB968]

I'm not a material science guy, but I've seen a lot of corrosion issues in the lab. I'm fairly sure the corrosion of this part has nothing to do with salt. The whole part isn't corroding, just the part where the two parts connect in the presence of a roll pin, and a fastener. Based on what I've see, I'm fairly certain our part failure is due to galvanic corrosion. I also wonder if the high voltage activity within the distributor could be a contributing factor.

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[flash]

possible



the fact of the matter is though, that of all of the cars i have seen out here, NONE of them have had this problem. with the exception of MB's car, i have only heard of it from cars that have spent time back east. the shops i have talked to here have also concurred with this observation.

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[tamathumper]

I'm no material science guy either, but I think salt is an important ingredient for galvanic corrosion to occur, at least according to Wikipedia.



"Galvanic corrosion is a process that degrades metals electrochemically. This corrosion occurs when two dissimilar metals are placed in contact with each other in the presence of an electrolyte, such as salt water, forming a galvanic cell."



Edit: BTW the underlines and bolding are theirs.

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[DaveN]

I know that I have a wet coast car and it's whole life was on the coast. Mine is in perfect condition save a little bit of black paint on the top chipping off.

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[MB968]

I was looking at the parts catalog for another part, and noticed your part on page 32/33, Illustration 105-05, part # 321 971 847 A

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