Starter terminal lube to prevent corrosion.

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The other week I replaced a starter on the MGM due to the key terminal corrosion. It did last 18 years, so I'm probably crazy to worry. The terminal was corroded so badly a small amount of torque broke it off. I tried soaking it and even heating it with a small butane torch.

However, I'm wondering if it is a good idea to put grease between the nuts and terminal lugs. I put a ton ceramic synthetic brake grease on the exterior of the terminals and the exposed brush line (had one of those rot out) but I'm thinking it could be a good idea to put in on the terminal nut. I figure the pressure would squeeze out the grease. I would use the Motorcraft product in a tube, but I hesitate because it is not really suggested for low voltage connections. Then again the car will probably be long rusted out before I have to worry about it again :lol:
 
Install the lug clean and dry. After installation I would spray battery terminal treatment onto the connection. You do not want any insulating gease (silicone, bearing grease etc) to get between the connection and do nothing but limit current flow and collect road dust and grime. An extra measure which I took, I made a heavy cable with soldered lugs on each end. I connected one end to the ground attachment on the engine and the other end to one of the starter mounting bolts.
 
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I keep a tube of this in all my tow vehicles and in tool box for just such issues. Found in electronic supply
 
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My local Walmart sales the NOCO MC101 kit that has a small can of the spray, and two battery washers for about $3 or $4, or you can buy the brush on kind from Amazon or where ever. You can do your battery, and have enough left over for that lug. Those washers are saturated with NOCO NCP2.

https://no.co/mc101
 
Originally Posted By: Lubener
Install the lug clean and dry. After installation I would spray battery terminal treatment onto the connection. You do not want any insulating gease (silicone, bearing grease etc) to get between the connection and do nothing but limit current flow and collect road dust and grime. An extra measure which I took, I made a heavy cable with soldered lugs on each end. I connected one end to the ground attachment on the engine and the other end to one of the starter mounting bolts.


That is not correct. There are numerous studies available online by private entities and the military that show there is no difference in conductivity between a connection using a dielectric grease as opposed to one that does not. And if it does collect some dirt, that is going to be on the outside of the connection, not between the terminals. You shouldn't be using that much grease anyway, only enough to block moisture from reaching the terminal.

And in fact it does do something important, at least for sliding plug contacts. All such plugs move in normal operation from vibration and the dielectric grease helps prevent fretting corrosion that will impede current flow.
 
I've used silicone dielectric grease before installing the wires and I've also brushed fluid film on the terminals after installation. Not sure if it matters much, though I doubt the FF holds up to the heat well.
 
loctite--dielectric-grease-ee100-lg.jpg


Get you a tube of dielectric grease. It is designed for electrical contacts. Brake grease is not designed for that application.
 
If that dielectric grease get between the connection, it could affect conductivity. Why not use something which is meant for this application, such as a battery terminal dressing?It will dry and seal out any moisture. Me, even lightly applied grease will attract grit and I prefer not to have this gunk on my starter terminal

He has a terminal with a nut. It should be tight and will not move. The cable is usually strain reliefed so its movement is minimal.
 
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Guess I should have posted this with the original post and picture. This is the same stuff electricians have to use when putting aluminum cable into lugs
 
Originally Posted By: bubbatime
loctite--dielectric-grease-ee100-lg.jpg


Get you a tube of dielectric grease. It is designed for electrical contacts. Brake grease is not designed for that application.


Thanks for all the suggestions.

I put the brake grease on the outside of the terminal and the connection was already made with a nut torqued down to about 8-9 ft/lbs. Didn't realize it can wick into the connector. The purple brake grease does not wash off.

The Motorcraft product is actually called Brake grease and Dielectric Compound, but the TDS says to avoid it for low voltage connections. It is mainly for the spark plug rubber boot. If some gets on the metal terminal I guess it will scrape off. I'm sure many coat the entire plug with it though.
 
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Is it for copper though or just for aluminum. I am familiar with that stuff for house wiring. Also, is it ok for low voltage/high current? It may not be fully conductive.
 
Originally Posted By: kschachn
Originally Posted By: Lubener
Install the lug clean and dry. After installation I would spray battery terminal treatment onto the connection. You do not want any insulating gease (silicone, bearing grease etc) to get between the connection and do nothing but limit current flow and collect road dust and grime. An extra measure which I took, I made a heavy cable with soldered lugs on each end. I connected one end to the ground attachment on the engine and the other end to one of the starter mounting bolts.


That is not correct. There are numerous studies available online by private entities and the military that show there is no difference in conductivity between a connection using a dielectric grease as opposed to one that does not. And if it does collect some dirt, that is going to be on the outside of the connection, not between the terminals. You shouldn't be using that much grease anyway, only enough to block moisture from reaching the terminal.

And in fact it does do something important, at least for sliding plug contacts. All such plugs move in normal operation from vibration and the dielectric grease helps prevent fretting corrosion that will impede current flow.
This is correct.. In low voltage low current RF connector applications grease keeps corrosion down and does not cause problems with conduction of the signals. If it works for microvolt connectors it won't hurt properly torqued low voltage high current applications.
 
Originally Posted By: Lubener
If that dielectric grease get between the connection, it could affect conductivity. Why not use something which is meant for this application, such as a battery terminal dressing?It will dry and seal out any moisture. Me, even lightly applied grease will attract grit and I prefer not to have this gunk on my starter terminal

He has a terminal with a nut. It should be tight and will not move. The cable is usually strain reliefed so its movement is minimal.
If the connection is properly torqued, metal to metal contact is assured. Using Si grease on my battery terminals has never caused a problem.
 
You don't want an electrically conductive grease, that is another fallacy. It needs to be an insulator so that when it migrates from the connection it does not cause a short.

Originally Posted By: ford46guy
Is it for copper though or just for aluminum. I am familiar with that stuff for house wiring. Also, is it ok for low voltage/high current? It may not be fully conductive.
 
Can you guys get in to your thick head that grease does NOT conduct? The entire idea behind the grease is to protect the surfaces which are NOT in contact with each other and prevent the oxidation from spreading further.

How many times simple physics need to be hammered in to your head???

There is indeed conductive grease but that is "thermally" conductive grease.
 
Originally Posted By: bubbatime
loctite--dielectric-grease-ee100-lg.jpg


Get you a tube of dielectric grease. It is designed for electrical contacts. Brake grease is not designed for that application.
If you want a Toyota plug boot to come off the plug without leaving part of it behind, best put some of the above grease inside the boot and on the metal connector on the plug. The longer they are on, the more likely they are to stick without grease.
 
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