I just pulled the Tranny and Transfer case and sent them off to be rebuilt. Now I have a pretty bare undercarriage and I thought it would be a good time to get the undercarriage coated with that rubber stuff...I don't know what it is exactly, but it looks nice.

When I called the Auto-Body shop to see what it would cost and to schedule an appointment, the guy told me that it's kind of a bad idea to do the undercoating on my truck, which is an 89 F-150 shorbox 4x4. He said that it would just trap moisture in between the floor pans and the carpet, and would rust it out. Go figure.

Is this guy right? I just want my trucks under-carriage to look really nice, and to last forever. I guess I could whip out a can of spray paint...I can't wait to get my fresh tranny and transfer case back...they're gonna look nice! I'm painting them Ford Blue.

Thanks,

Scott

 

I have never heard this before, and as long as the truck is clean and dry when you get the undercoating, I don't see how this would trap moisture. I have applied undercoating to my 94 Ford Explorer several times over the past 8 years and have had no problems... To me, it actually protects the underside of you truck...Right??

 

Yeah I thought it would too, but from what the guy told me...it's a bad idea. Maybe he just doesn't want to do any work lol. I just really want my truck to look nice from top to bottom...and now that I've rebuild almost everything drive-train wise (motor, tranny, t-case, rear diff) I just want it to look professional. Black Spray paint?..maybe...but I think that rubber undercoating would look a lot sharper.

And...is it alright to spray that stuff on the rear axle? I was thinking it might make it hard to work on the truck with the bolts covered with tar, lol. It's hard enough being underneath that thing all day, let alone trying to scrape off rubber from the heads of bolts.

-Scott

 

Yeah, I wouldn't spray any on anything that will/could require service i.e. tranny, axle, drive shaft...etc.

 

I used rubbercoating before under the cab and it worked fine. This time I used roll on bed liner under the cab on a different truck. I think it will work better then the rubber coating. Either should be fine. Better then rust!

 

It all depends who does the job,If you put on too thick it will just crack and alow water to be trapped ,if you put on where it blocks drain holes,it will cause faster rust out.
You don't want to put it directly over exhaust unless your sure you have plenty of clearance as to not cause a fire.Do not put it on differentials it will keep heat within.
I use it all the time on my trucks. But I was in the trade(bodyshop) and knew how to install it .

Rich

 

I think the man might have ment that it would trap water in on the metal part instead of the side that was undercoated.

 

You shouldnt have a problem undercoating. It is something that is also easy to do i did my own in just a few hours on a saturday morning. I had a lift though so that made it a lot easyer but i also saved a lot doing it my self to but i also work in a body shop but i just used the 3M undercoat in a rattle can.

 

The best undercoating is the free undercoating provided by a leaking oil pan gasket.

 

Yeah that's hilarious! I used to have the benefit of a leaky oil pan, but since have rebuilt the motor so everything under the hood is shiny clean either Aluminum, black, or Ford Blue.

By the way...that Auto-Body shop never provided me with any actual cost estimate on the job- how much could I expect to pay for this?

Maybe I'll just rent a pressure washer, hose the hell out of the undercarriage...then coat it myself.

Is there anything that is GOOD for coating my rear axle? Just spray paint? I just put a TrueTrac in the 8.8, so I painted the diff cover that nice Ford Blue, but the axle still looks dull and shabby....I gotta make it look new!

Thanks

Scott

 

If you put it over any rust- on a body panel - you will be screwed. I think rust performs better this way. The guy may have assumed that an '89 would have some rust. So I'd make sure to kill any of that first and I'd probably use some kind of sealer first or in lieu of the undercoat stuff.

 

I live in Montana. The body on this truck is PERFECT except for a small dent in the passenger side front quarter panel. There is absolutely zero rust. That's part of the reason I haven't sold this truck already...and the fact that it's practically a new truck already since I've looked at or rebuilt almost everything mechanical on this pickup. ...So I don't know why that guy would tell me that it isn't a good idea to put rustproof on my pickup. I seem to think he may be lazy.

Thanks a million for all of your support everyone-

SUPPORT THE TROOPS!!!!!!!!!!!!!!!!! PRAY FOR THOSE IN THE MIDDLE EAST!!!!!!!


-SCOTT

 

If you live near ay of the (mini) cities in Montana that use that caustic de-icer on the roads i'd do something or they will be rusting for sure.

 

The best thing I have found for things like a rear end housing is CHASIS SAVER. I got it from an autopaint store. Drys very hard and feels really smooth. As for the undercoating, I don't see how it could hurt when applied to a clean surface.

 

I used Pore15 under my truck. Its drys hard as a rock and is made to cover and stop rust as well.