Undercoating

tacojoel

Well-Known Member
I'd be carful where your spraying that stuff. I don't think you want it creeping into any oil seals like i noticed on the differential pinion gear.
 

JayQQ97

MW surVivor ... MT. 279k miles
oh no! :(
i tried to limit the overspray cramped under there stretching to reach at it
and i don't even know what pinion gear is, i shall have to research that!
 

tacojoel

Well-Known Member
oh no! :(
i tried to limit the overspray cramped under there stretching to reach at it
and i don't even know what pinion gear is, i shall have to research that!
Its in your differential where its bolted to a flange that ties to your u-joint. Theres an oil seal around that flange. Last thing you want is this cosmoline collecting any dirt causing abrasion with that seal as the pinion gear spins the driveshaft. If that seals ends up leaking fluid you'll likely know the cause.
 

JayQQ97

MW surVivor ... MT. 279k miles
cosmoline is going to attract dirt now??
i thought i was trying this product to get away from all of that mess :confused:
...got the first bit of mild rainy driving with it yesterday, over 50 miles, the water should bead as a wax would? and keep its slick look
 

tacojoel

Well-Known Member
Dirt will build up on a cosmoline coated surface just as it would on a bare frame. There's no getting around it. People go to car wash's. I don't wash my trucks, but i am careful where i spray cosmoline. Idk, if you'll ever have any issues, but you certainly don't want to try, and create one.
 

JayQQ97

MW surVivor ... MT. 279k miles
Dirt will build up on a cosmoline coated surface just as it would on a bare frame. There's no getting around it. People go to car wash's. I don't wash my trucks, but i am careful where i spray cosmoline. Idk, if you'll ever have any issues, but you certainly don't want to try, and create one.
i am now into the 4th year of checking out & trying everything and repair whats needed underneath it all to confidently wheel in the salted MW winters with NO 2nd guessing after i saw what i saw at that local salvage lot one day in mid-2o19... it scared the bejeebers outta me i have not ever seen anything so horrific until that other place popped up with all sorts of pictures :eek:, i never knew it was a REAL issue with these trucks
 

tacojoel

Well-Known Member
i am now into the 4th year of checking out & trying everything and repair whats needed underneath it all to confidently wheel in the salted MW winters with NO 2nd guessing after i saw what i saw at that local salvage lot one day in mid-2o19... it scared the bejeebers outta me i have not ever seen anything so horrific until that other place popped up with all sorts of pictures :eek:, i never knew it was a REAL issue with these trucks
Heck, a friend of mine had a 2005 dodge dakota. In less than 10 years his frame rotted in half on one side the other side rail had a hole rusted through big enough to poke a fist through. I been through those emission inspections stations here where those cheap korean cars end up throwaways after their found unsafe for the roads due to excessive rust.
 

JayQQ97

MW surVivor ... MT. 279k miles
Is that black cosmoline something you would spray on the rear brake drums?
I have it sprayed on the rear backing plates
The powdered drums are wearing and crusty looking winter will make it worse lol
 

tacojoel

Well-Known Member
Forgot to add only stuff i painted my drums in the past with was rustoleum high heat 2,000 degree spray paint. Just make sure its fully cured before installing the wheels back on.
 

JayQQ97

MW surVivor ... MT. 279k miles
No. Keep that stuff away from any brake parts that get hot. Backing plates are ok on the outsides.
i meant outside visible area not on the inside LOL

i do have some pricey high-heat black paint i may use next season but have to remove the rust under cracked powdercoating
 

JayQQ97

MW surVivor ... MT. 279k miles
Forgot to add only stuff i painted my drums in the past with was rustoleum high heat 2,000 degree spray paint. Just make sure its fully cured before installing the wheels back on.
does that product paint over the rust?

do you have to bake it in the oven at diffrent temps 3x ?
 

Rock62

Well-Known Member
Ok.....some hard facts. Rust happens. It can't be stopped. Yes, rust is accelerated by salt (road deicer) and water.

Spraying product on the heavy cast iron parts (axle housings, diff housings....etc) doesn't have much effect. I have never heard of a diff housing or axle housing rusting through. The parts most needing protection are the thinner steel parts (body panels, formed frame members, steel stampings.....) My first car was a '63 Buick Skylark that I purchased in '76. Swiss cheese had fewer holes.

I've lived in this rust belt nearly my entire life. The best defense (IMHO) is not coating everything with some product, but to keep the undercarriage dry and clean. No water then corrosion slows. No dirt then nothing to hold water.

When I purchased my truck, I inspected the undercarriage. I was fortunate, the frame had been replaced in 2018 under recall. I purchased it in Feb 2020. During my inspection I found all sorts of debris. Gravel, gravel dust, corn stalks, soybeans, dried mud...... I spent several hours under the truck clearing and removing the debris. After this work was complete, I began to address the loose shields and panels. These were moved into position and fastened. I also paid special attention to all the drain holes in the frame and body panels to be sure these were clear.

Each Spring, I'll spend time under the truck with a hose to flush the under carriage. During the winter, when the weather cracks above freezing and the streets are mostly dry, I'll visit the local pay-n-spray to rinse off as much as I can from the undercarriage,

Will my truck rust? Absolutely. Can I stop the rust? No. Can I slow the process? Absolutely. My truck is already 15 years old. I don't expect it to last forever.

One last point. All the anti-rust product sprayed on everything will make any service/maintenance work extra nasty.
 
Last edited:

JayQQ97

MW surVivor ... MT. 279k miles
axle housing parts can rust through!!! i have seen pics of saturated rear diff gear oil on the back cover where the fill plug is at (not sure what that part is called)

1668002721706.png

this is from Maine
1668002914370.png
this is not mine LOL
just a random web pic from the state of NH
 
Last edited:

JayQQ97

MW surVivor ... MT. 279k miles
this report of a Gen1 in ChicagoLand

My axle housing rotted out in 2 spots.. the pumpkin and the right tube where its welded to the center housing. I just ended up replacing the entire axle housing with a new one from Toyota. but if yours is just the pumpkin i believe theres a repair plate you can get and weld on.
 

Rock62

Well-Known Member
@JayQQ97

I didn't say it couldn't happen. It is unlikely to happen on cast iron parts.

I suspect the parts you referencing are made from formed steel in a weldment. Many times, a weld is a prime location for corrosion the get a toe hold.
 

JayQQ97

MW surVivor ... MT. 279k miles
@JayQQ97

I didn't say it couldn't happen. It is unlikely to happen on cast iron parts.

I suspect the parts you referencing are made from formed steel in a weldment. Many times, a weld is a prime location for corrosion the get a toe hold.
An oil pan is not cast iron or is it?
 
Top