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View Full Version : New alternator mount - dissimilar metals



dhardison
07-06-2006, 07:58 AM
Before the '06 Power Tour I installed the following low-mount alternator bracket from March.

https://static1.pt-content.com/images/noimg.gif
(http://www.marchperformance.com/products/chlowmount.jpg)

The brackets are billet aluminum but the sleeves in which the bolts pass through to the block are steel. Everywhere I have aluminum to steel contact (brackets to sleeves and brackets to block), I have what looks to be a metallic reaction occuring. So far is has eaten the clear off the brackets and is leaving an acidic-type residue. It's bad enough that the residue is actually dripping on the the front crossmember.

Is this some sort of dissimilar metallic reaction? How can I stop it (before it eats my billet brackets away)?

Thanks.

BonzoHansen
07-06-2006, 08:13 AM
I'd call March & complain. Seems kind of fast.

Matt@RFR
07-06-2006, 08:23 AM
Gotta love companies cutting corners. What you're looking at is electrolisis I believe. Replace those steel sleeves with stainless sleeves and the problem should go away immediately. Let me know if you need help and I'll just make them for you.

dhardison
07-06-2006, 11:21 AM
Thanks Matt, but what about the electrolisis between the bracket and the block? Is there any kind of paste/paint I can use to stop this from happening with the block?

BADVELLE
07-06-2006, 11:33 AM
It looks like Matt has helped you out, but why are you not going to call the company on this issue??? At least snap some pic's and send them, if this is happening to you, it has to be happening to everyone else that has bought this particular Alt. setup.:dunno:

dhardison
07-06-2006, 11:43 AM
Oh I'm going to call, rest assured.....

Matt@RFR
07-06-2006, 11:55 AM
It looks like the brackets that bolt to the block don't move as you adjust belt tension, so the paint on the block should provide the isolation you need. But if the paint is worn, I would think a non-dialectric grease, silicone or a thin stainless shim would do the trick.

TonyL
07-06-2006, 11:58 AM
yeah. Post those images here, I'd like to see them.

Galvonic reaction should be somthing they thought of. The more you know...

dhardison
07-07-2006, 03:06 AM
I'll take some pics and post them this weekend.

I called March Performance yesterday afternoon. The tech guys had never heard of this occuring (big surprise). They speculated that the alternator was somehow providing current to the block.:rolleyes: I'm going to call back again today and speak with their head engineer.

GetMore
07-07-2006, 06:12 AM
I called March Performance yesterday afternoon. The tech guys had never heard of this occuring (big surprise). They speculated that the alternator was somehow providing current to the block.:rolleyes: I'm going to call back again today and speak with their head engineer.
Wow, that's really stupid. "The alt. is somehow providing current to the block."
How do they think the alternator completes it's circuit? Oh, it must just pump the electricity out by the positive wire, it doesn't need to be connected to ground anywhere.