Subaru's dirty little secret.

[PoorManQ45]

The subframe is at the front of the car(obviously). So isn't it getting pounded much harder by the salt on the roads?

[4cefed]

Not quite sure, but what does trans oil do to help prevent rusting? I know oil coatings are good for metals, but why specifically trans? I read it twice in here...

I'm not sure why exactly, but a lot of guys around here used old ATF to undercoat with. ATF has a penetrating quality and I think it either sticks longer or won't evaporate as quickly as regular motor oil.

As soon as you undercoat the whole car, blast up and down a dirt road and give that oil something to stick to.

[PapaSmurf2k3]

I'm not sure why exactly, but a lot of guys around here used old ATF to undercoat with. ATF has a penetrating quality and I think it either sticks longer or won't evaporate as quickly as regular motor oil.

Yup, ATF penetrates well and is an excellent lubricant and rust inhibitor. It also doesn't seem to eat seals much at all, which would lead me to believe it won't compromise your factory rubberized undercoating.

Don't forget, 50/50 mix of ATF and Acetone is the world best rusted nut and bolt buster (way better than PB blaster).

[PoorManQ45]

OP is updated with pictures of the subframe out of the car.

Upon inspection, I've realized that no level of painting is going to stop this from happening again, and I have to assume that the new Subaru part will fall prey to a similar fate if I don't do something. I cant afford to dip it in paint, but some sort of petroleum based rust inhibitor, might prove cheaper. Especially if its in the form of 5 quarts of Nissan Matic K transmission fluid, that I drained from the Maxima last week. Decisions decisions.

I know it would be difficult(and expensive), but grease would be a much better choice. Buy it in a 5 gallon bucket. You would heat it up in a tub that was large enough to fit your part. Then submerge the part in it. Moving it around to get everything coated. Then remove the part and allow the excess to run out. Everything will have a nice and nasty coating on it that should last a really long time.

[PapaSmurf2k3]

ATF would probably work just as well... and if you wanted grease, you could get that spray can of white lithium stuff that you could just spray on there and it turns into grease. Comes with one of those plastic straw type things so you could just get it in a hole on the subframe and give it the "Swizzlestick" motion to get everything all covered.

[PoorManQ45]

ATF would probably work just as well... and if you wanted grease, you could get that spray can of white lithium stuff that you could just spray on there and it turns into grease. Comes with one of those plastic straw type things so you could just get it in a hole on the subframe and give it the "Swizzlestick" motion to get everything all covered.

ATF does not have much viscosity to it. It will be gone in a month or two. Grease is on there until you remove it with a chemical that breaks it done.

The Lithium would work better then ATF, but how would you coat the inside?

[hachiroku781]

Quite a problem here in the North east. They cause such a problem to many newish cars. I think that dealerships should rust proof the major components of a chassis. Thank god my previous cars have been pretty clean underneath.

[assassin7420]

POR 15, Or rhino line the thing.

http://www.por15.com/

[4cefed]

I'm going to be trying this out in the fall, but I guess you heat up the ATF and then pour it in a bug sprayer to get inside rockers, and subframes.

[PapaSmurf2k3]

I'm going to be trying this out in the fall, but I guess you heat up the ATF and then pour it in a bug sprayer to get inside rockers, and subframes.

Just put it in one of those spray bottles that has the adjustable nozzle... it really doesn't have to be very hot either.

ATF does not have much viscosity to it. It will be gone in a month or two.

No it wont. That open oil catch pan has been in my car port for about a year (with oil in it)... its still there. Oil doesn't mysteriously disappear... just ask anyone in the Gulf of Mexico. I work with ATF all day long. We have parts that have been sitting after being coated in ATF for well over 2 years that are STILL coated in ATF. We have vehicles that we do transmission work to that get ATF on the chassis... and every time I crawl under one, its still there from a previous job.

how would you coat the inside

swizzlestick

[IanS]

ATF does not have much viscosity to it. It will be gone in a month or two. Grease is on there until you remove it with a chemical that breaks it done.

The Lithium would work better then ATF, but how would you coat the inside?

Its funny, you think you know what you are talking about, but seriously, STFU.

High viscosity in this case is a BAD thing. Thick bearing grease, unless heated to very high temperatures will not have the penetrating quality that ATF will. Plus any petroleum based grease is going to get rubbed off easily, plus it will destroy any rubber based under body coating, as well as any bushing that it comes into contact. ATF is much easier on rubber, and its much easier to work with.

If you think you know what you are talking about, then why do both BMW and Mercedes coat the bottom of cars sold in salt states with an oil based product very similar to ATF?

[PoorManQ45]

ATF does not have much viscosity to it. It will be gone in a month or two.

No it wont. That open oil catch pan has been in my car port for about a year (with oil in it)... its still there. Oil doesn't mysteriously disappear... just ask anyone in the Gulf of Mexico. I work with ATF all day long. We have parts that have been sitting after being coated in ATF for well over 2 years that are STILL coated in ATF. We have vehicles that we do transmission work to that get ATF on the chassis... and every time I crawl under one, its still there from a previous job.

That's interesting. I'll have to look into what causes this.

If you were to put an oil of a similar viscosity as ATF(<10w) on something, then hang it up, all the oil would drain off.

I wasn't thinking the ATF would mysteriously disappear. I was thinking more along the lines of a moving vehicle. Like rain on the windshield at 70mph, the fluid would tend to be pushed to an edge. Once there it would be forced off.

[IanS]

That's interesting. I'll have to look into what causes this.

If you were to put an oil of a similar viscosity as ATF(<10w) on something, then hang it up, all the oil would drain off.

I wasn't thinking the ATF would mysteriously disappear. I was thinking more along the lines of a moving vehicle. Like rain on the windshield at 70mph, the fluid would tend to be pushed to an edge. Once there it would be forced off.

Hahahahahahahahah


hahahahahahahahahahahahahahahah

hahahahahahahahahahahhahahahahahahahahahahahahahhahahahah


Seriously?

Go get yourself a piece of steel, dip it in ATF or motor oil, and hang it up in your garage. You can come back when it ALL comes off.

Sorry to break it to you, there will be oil residue on that piece of metal for as long as you let it hang. Unless you clean it with some kind of solvent.

Metal is porous. Just because you can't stuff your finger through it, doesn't mean oil wont soak in.

Petroleum has some very strange properties, especially once it has been modified to such an extent by chemists. I think you need to retake high school chemistry.

[PoorManQ45]

reading now.

ps. You mentioned petroleum doing strange things, but you said that any petroleum grease would easily be wiped off. Make up your mind...

Go get yourself a piece of steel, dip it in ATF or motor oil, and hang it up in your garage. You can come back when it ALL comes off.

Sorry to break it to you, there will be oil residue on that piece of metal for as long as you let it hang. Unless you clean it with some kind of solvent.

Take an air compressor to the piece and see how much oil and residue is left...

[IanS]

reading now.

ps. You mentioned petroleum doing strange things, but you said that any petroleum grease would easily be wiped off. Make up your mind...

The bulk of it would wipe off, being wasteful, as well as bad for the environment. Different types of petroleum do even stranger things. Im not saying it wouldn't work, but it would be much less efficient, and more harmful.

Take an air compressor to the piece and see how much oil and residue is left...

HAhahahahahahAHHAHAHAHAHAHAHAHAHAH

HAHAHAHAHAHAHAHAHAHAHAHAHAHAHHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAH

HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHHAHAHAHHAHAHAHAHAHHAHAHAHHAHAHAHAHHAHAHAHHAHHAHHAHAH

Really? You really believe blown air would clean it?

Try rebuilding an auto transmission one time. You could let all the parts sit through all of hurricane Katrina for all the good it would do.

Air, water, rags, dirt, pant legs, you could even try sea monkeys. Guess what, there will still be large amounts of residue EVERYWHERE.

Scientist have been perfecting the way ATF and motor oil work for 100 years. Sticking to everything is what its supposed to do, because oil in the bottom of the pan isn't lubricating anything during start up.

[PoorManQ45]

If you think you know what you are talking about, then why do both BMW and Mercedes coat the bottom of cars sold in salt states with an oil based product very similar to ATF?

Can you provide some information on this? Searching is not yielding any results.

Alright, looked over some information again.

Both grease and Oil(ATF in this case) would work if the metal were constantly stationary. Anything that can prevent oxygen from reaching the metal will help to prevent rust.

The problem with using the ATF is that it will leave a very thin layer of protection. With a moving vehicle you have the underside of the vehicle constantly bombarded with debris. Basically getting sandblasted. This will penetrate the ATF film(look into film lubricants as this is the property you're looking for) over time.

A grease coating will simply have a thicker film.

Both solutions will work. One will simply work longer.

And no, you don't have to heat grease to any extreme temperatures. Look up "grease flow properties". This could be done with a tub over an open fire.

Thanks, needed a refresher a film strengths

Scientist have been perfecting the way ATF and motor oil work for 100 years. Sticking to everything is what its supposed to do, because oil in the bottom of the pan isn't lubricating anything during start up.

You might want to read up on dry startups. Leave an engine sit for a long period of time then start it(assuming all attached components and fuel are in working order). After this is done disassemble the heads and examine the cylinder walls. You will have score marks.

The oil film will stay there for a good period of time, but it will eventually flow off.

[Urabus GodofTraction]

All I know is that the giant oil stain I left on the concrete at my parents house with I was an adolescent grease monkey STILL hasn't come up.

[PoorManQ45]

All I know is that the giant oil stain I left on the concrete at my parents house with I was an adolescent grease monkey STILL hasn't come up.

Acid will do the trick

[Urabus GodofTraction]

All I know is that the giant oil stain I left on the concrete at my parents house with I was an adolescent grease monkey STILL hasn't come up.

Acid will do the trick

And leave a huge, just as obvious spot where the oil spot once was.

[PoorManQ45]

And leave a huge, just as obvious spot where the oil spot once was.

Yep.

[Jesda]

And leave a huge, just as obvious spot where the oil spot once was.

Just tell your parents you cut up a hooker in the garage.

[Razi]

All I know is, cleaning grease off my hands is tons easier than ATF oil.
And caked on oil sticks onto surfaces pretty damn well.

[s0m3th1ngAZ]

Rust is the oxidization of iron to iron oxide...ATF just serves as a barrier from oxygen. Though there are much better coatings out there, it works really well for what it costs.

[PapaSmurf2k3]

whatever floats your boat man... just saying ATF will probably be easier/cheaper.

[IanS]

Can you provide some information on this? Searching is not yielding any results.

No info, just words from a Mercedes mechanic. According to him, its one of the better kept secrets in the industry. All I know is every Merc, or Bimmer I rack up, has a coating of tan/brown oil on the under side of the car.

Both grease and Oil(ATF in this case) would work if the metal were constantly stationary. Anything that can prevent oxygen from reaching the metal will help to prevent rust.

The problem with using the ATF is that it will leave a very thin layer of protection. With a moving vehicle you have the underside of the vehicle constantly bombarded with debris. Basically getting sandblasted. This will penetrate the ATF film(look into film lubricants as this is the property you're looking for) over time.

A grease coating will simply have a thicker film.

Both solutions will work. One will simply work longer.

You're forgetting one thing, penetration. Film is only a small part of a larger equation. ATF is going to go where grease never will. Not to mention, it would be nearly impossible to get a uniform layer of grease on any one part. Oil is much easier to work with, and I think the fact that you believe one will last longer, is negligible.

Remember I get my hands greasy for a living. I can wash axle grease off in a heartbeat, where as ATF stays with you unless you douse yourself with industrial degreaser. You can wash your hands till they are bloody, and you still feel a little slimey.

And no, you don't have to heat grease to any extreme temperatures. Look up "grease flow properties". This could be done with a tub over an open fire.

Thanks, needed a refresher a film strengths

So you are saying I should fill a large vat with grease, then heat it over an open flame like some sort of witches stew? That sounds like an awful lot of work for no provable benefit.

You might want to read up on dry startups. Leave an engine sit for a long period of time then start it(assuming all attached components and fuel are in working order). After this is done disassemble the heads and examine the cylinder walls. You will have score marks.

The oil film will stay there for a good period of time, but it will eventually flow off.

Define good period of time, and eventually.

Its not 1965 any more. HUGE advances have been made in lubrication technology.

Do some research on viscoelasticity, so you can understand how synthetic polymers have completely changed the way most petroleum based lubricants perform.

Acid will do the trick

Honestly, you should stop opening your mouth about that which you do not understand.

Using acid to clean oil off of concrete is ludicrous. What do you store acid in?

Plastic bottles, do you know why? Because petroleum does not get broken down by it.

By pouring acid on an oil stain, all you will do is make a big oilly smelly acidy mess, while damaging the concrete below. I have acid etched floors before. Any oil thats on the floor prevents the acid from working. You need to use a solvent to LIFT the oil out of the pores of the concrete, which is incredibly difficult because concrete is so porous.

[PEZi]

So you are saying I should fill a large vat with grease, then heat it over an open flame like some sort of witches stew? That sounds like an awful lot of work for no provable benefit.

[Razi]

Well, about the oil flowing off cylinder walls.
Engine oil is different from ATF, if I make a mistake and get some engine oil over myself I can wash it off no problem, ATF on the other hand...quite difficult.
Also, we're talking about a smooth cylinder wall vs a rougher surface of the undercarriage.

Either way...a slightly leaky front main seal coats my front subframe once in a while and keeps it rust free, and even when I wipe it off with a towel it leaves behind a film of oil that repels water.
And a spare KA I have in my backyard is coated in engine oil gunk and after getting rained on constantly, none of it has washed away.
I'd imagine that applying ATF, which will eventually cake up, would work even better.

I do understand how you'd get the idea that applying grease over the subframe could help prevent rust, it will, but I think something that is harder to wash off and easier to apply into hard to reach spots would be better.
I use grease on a lot of the nuts and bolts I put onto my car to prevent them from seizing up and it's been doing great so far, but after a drive in the rain, any excess on the outside is washed off. Now I'm sure you can find better grease to coat the whole subframe is but coating it in oil is more time and cost efficient, especially because you can easily get it to go inside all the little crevices and hard to reach places.

[Jesda]

So you are saying I should fill a large vat with grease, then heat it over an open flame like some sort of witches stew? That sounds like an awful lot of work for no provable benefit.

I will subscribe to your Youtube channel.

[Razi]

So you are saying I should fill a large vat with grease, then heat it over an open flame like some sort of witches stew? That sounds like an awful lot of work for no provable benefit.

I will subscribe to your Youtube channel.

[PoorManQ45]

Can you provide some information on this? Searching is not yielding any results.

No info, just words from a Mercedes mechanic. According to him, its one of the better kept secrets in the industry. All I know is every Merc, or Bimmer I rack up, has a coating of tan/brown oil on the under side of the car.

I really would be interested in this. Maybe next time you talk to one of the mechanics could you ask them for a little more info so I could read up on it? It's obviously there because you see it all the time, just curious.

Both grease and Oil(ATF in this case) would work if the metal were constantly stationary. Anything that can prevent oxygen from reaching the metal will help to prevent rust.

The problem with using the ATF is that it will leave a very thin layer of protection. With a moving vehicle you have the underside of the vehicle constantly bombarded with debris. Basically getting sandblasted. This will penetrate the ATF film(look into film lubricants as this is the property you're looking for) over time.

A grease coating will simply have a thicker film.

Both solutions will work. One will simply work longer.

You're forgetting one thing, penetration. Film is only a small part of a larger equation. ATF is going to go where grease never will. Not to mention, it would be nearly impossible to get a uniform layer of grease on any one part. Oil is much easier to work with, and I think the fact that you believe one will last longer, is negligible.

Remember I get my hands greasy for a living. I can wash axle grease off in a heartbeat, where as ATF stays with you unless you douse yourself with industrial degreaser. You can wash your hands till they are bloody, and you still feel a little slimey.

When grease is heated to the point of easily flowing it will penetrate very well. That's why I started off with the suggestion of heating it. I understand that it will simply cover the metal if you don't heat it.

And no, you don't have to heat grease to any extreme temperatures. Look up "grease flow properties". This could be done with a tub over an open fire.

Thanks, needed a refresher a film strengths

So you are saying I should fill a large vat with grease, then heat it over an open flame like some sort of witches stew? That sounds like an awful lot of work for no provable benefit.

You might want to read up on dry startups. Leave an engine sit for a long period of time then start it(assuming all attached components and fuel are in working order). After this is done disassemble the heads and examine the cylinder walls. You will have score marks.

The oil film will stay there for a good period of time, but it will eventually flow off.

Define good period of time, and eventually.

Its not 1965 any more. HUGE advances have been made in lubrication technology.

Do some research on viscoelasticity, so you can understand how synthetic polymers have completely changed the way most petroleum based lubricants perform.

The issue seems to occur once you start approaching 6 months.

Acid will do the trick

Honestly, you should stop opening your mouth about that which you do not understand.

Using acid to clean oil off of concrete is ludicrous. What do you store acid in?

Plastic bottles, do you know why? Because petroleum does not get broken down by it.

By pouring acid on an oil stain, all you will do is make a big oilly smelly acidy mess, while damaging the concrete below. I have acid etched floors before. Any oil thats on the floor prevents the acid from working. You need to use a solvent to LIFT the oil out of the pores of the concrete, which is incredibly difficult because concrete is so porous.

Sorry, I got my steps mixed up. Acid is a finishing step once you've got the concrete cleaned and are prepping it for sealing.