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View Full Version : Magnesium transfer case has started to oxodize (turning to powder)


letsgo
10-05-2002, 04:40
Just changed all the oils in the drive train (2 diff, tranny, transfer case).
I noticed a factory installed sticker attached to the transfer case (TC), stating that any attachments made to the Magnesium TC had to be of a compatable materials to prevent oxidization, then I noticed most of the case bolts and washers had a white fuzz on their edges, so with my finger nail I was able to remove the fuzz, on further examination, the case at the edge of the washers is also being eaten (turning to a powder).
I would have to assume that the GENERAL isnt heeding his own advice and has used the wrong bolts and washers, there is also oxidization where a wiring loom is tight against the case.
This truck hasnt seen a winter (snow or salt) so the oxidization is from the rain only, there could be a stray voltage on the Tansfer Case causing an increase in electrolosis.
I need to know if other Canadian American trucks have the same problem.
I am not sure if applying oil or grease to the infected areas will slow down the process.

[ 10-05-2002: Message edited by: letsgo ]</p>
Kevin
10-06-2002, 12:25
Thats one reason the older trucks are better than the newer ones. The case has a zinc coating. Scratch it and you have 6 months to a year than its time for a new case.

Kevin
thechevyhdman
10-07-2002, 19:55
If that was the case I think Gm would be replacing the TCs in every truck sold in the Northeast or anywhere road salt is used. Where did you hear that one from.
letsgo
10-08-2002, 14:14
chevyhdman
It's my truck, and 50% of all washers have a buildup of oxide that can be scraped off with my finger nails.
what I would like to know. Have the transfer cases always been cast of magnesium. Or were they built for the Duramax only .
Is there an anti oxidant for magnesium as there is for aluminium wire?
I would add that this forum is my only source for duramax information as it is for many other members, If I can get a bit more input I would be most appreciative.
Black Dog
10-08-2002, 15:10
Magnesium has been used off and on for transfer case housings for about the last 10 years. Very few were in GM applications, mostly Ford. It is done for weight savings. Corrosion has not been a big problem with the mag cases. It is mostly a weight vs. cost trade-off for the OEMs.
Kevin
10-08-2002, 16:12
Where did you hear that one from.

All of GMs newer t-cases are this way. They started back in the late 90's with the auto 4x4. GM had a TSB when these first came out. Basicly you scrath the coating and it will rot. Good news is you can get just the case only, without getting the internal parts. Newer is not always better.

Kevin
TLA
10-08-2002, 18:16
Do a web search for Corrosion-X. It is an aircraft anti-corrosion material in an aerosol can. There is a thin film type, and a thicker type. I use both all the time, and it stops corrosion in it's tracks, and reduces reformation. I recall the people being really helpful, but as I bought a case of each, I haven't talked to them in a long time.
TLA
10-08-2002, 18:30
Try http://www.corrosionx.com/. There is a pretty good description of the products there. I have used the Aviation on all types of metal, including magnesium and magnesium/steel. Good luck.