Brass sender - Aluminum housing reaction?

[moose]

Looking at installing a tranny temp gauge. Guys on the Dodge forums are plugging the brass sender into a port on the aluminum tranny housing. For whatever reason, my account on Dodge forums haven't been approved, some for over a year, so I can't ask them. But I thought, and Google agrees, that brass/aluminum contact can cause corrosion...has anyone here done this? Another viable option is to put a brass inline T-fitting on the exit side, but I'd rather put the sensor directly in the housing as I don't want to hack up the hardline.

EDIT: And that would also be a brass/aluminum contact point, which would possibly mean moving the sensor further away and plumbing it into the hose...

[Chris]

IIRC those create a white powder corrosion that's aluminium oxide which is a fancy way of saying aluminum rust. It makes it very hard to remove after corroded. I'm sure someone will correct me if I'm wrong.

[dieseldoc]

Nope you totally right about that one.
Steel an aluminium will do the Sam thing....
Electrolis is the root cause and is very hard to stop. Thus the use of thick gadgets between heads an blocks.
Thus why diesel engines coat the piston with things like Kevlar and the an aside them in key places as well.

[moose]

So thread sealant could possibly reduce this. My concern is that it will corrode to the point that it causes a leak.

[Jim]

I was thinking teflon tape - but you do have some odds that the tape, even with multiple layers, could have metal to metal contact.

Would you need to remove/unscrew this item?

[moose]

I was thinking teflon tape - but you do have some odds that the tape, even with multiple layers, could have metal to metal contact.

Would you need to remove/unscrew this item?

PTFE (teflon) sealant, not the tape variety. Only reason to remove would be if/when the sender fails. Might just need to plumb an inline setup....I've had bad luck with aftermarket temp senders for water temp. Replaced 3 within a year due to flat out failure on my Cutty, 2 Derale and one from Oreillys. The end result was a manual switch with one eye on the gauge...

So, I just reaffirmed that my fear is a reality. Inline it is, thanks everyone.

[Jim]

If you're doing inline, consider going direct - for a short test - so you can see what temps you have and then switch to inline and see what temp diff you have (I'd expect lower, but by how much is the question). If you end up staying in-line, you'd know the value to adjust for if it were direct (20F, 40F, 0F diff?).

[moose]

Great idea and it'll keep my mind occupied when driving...used to esstimate my MPH based on RPMs...

[fredrok]

This would be a case of way overthinking a non-issue really. There's not a vehicle out there that doesn't have dissimilar metals mated up. Most sensors are brass (or a composition thereof) and some are steel but many are screwed into aluminum manifolds, blocks, tranny cases all the time without epidemic. I prefer liquid thread sealant but use whatever you like, screw it in and move on. NOTHING like that would cause near the corrosion magchlo does on your rig.

[moose]

This would be a case of way overthinking a non-issue really.
Yup, but that's how I roll.

[dieseldoc]

magchlo eats everything.
Anything copper in huge danger with this carp.

So the Fed thinks magchlo is ok to use, yet it easy most all types of metals.
And yet we are being told we can't modify our own vehicles.

[fredrok]

Yup, but that's how I roll.

Hey, no sweat bro, just trying to save you a few grey hairs!

[Chris]

Always better to over think than under think. ;)