I have several friends who farm.

Every year when the change all the oils in thier tractors, they have
done this gear oil treatment to the grain trucks, whch sit much.
Well one friend I know is still using 70's and 80's two ton  trucks, and
none of them have any rust.
They are Chevy trucks and we all know how the rust attacks them.
I guess the trick is to dump the oil in the panels and let it drain for
a day or two.
No stink, no dripping, no rust.
This is all I can tell you from what I have seen,and it must work OK.
Good Evening,
Fred

E-mail message

Mr. David,
Pour the used gear oil into your door panels, and rear quarter panels.
This will stop any rust or corrosion fom starting--or getting any worse
if you have some.
Old Farm trick to recycle gear oil and it works.
Not a bad idea, though the strong and very sulferous odor makes me
reluctant to use it on door panels. I might consider pouring it into my
lower control arms, though. I've seen vans where those were rusted out
from the inside.
--
David Brodbeck, N8SRE
'82 Diesel Westfalia
'94 Honda Civic Si

Fred