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Rusted Frame "Underhaul"

TowWhiteAv2500

Full Member
Joined
Jan 29, 2014
Messages
46
Location
Ohio
I "Underhauled" my 02 2500 in the spring of this year, it took 5 weeks of working on after work during the week (I was working on my camper at my parents house on the weekends installing a new roof).  This started with me wanting to change the fuel filter because I suspected it was original and I didn't think the lines would come off with out snapping due to rust (I was right). After replacing the brake lines and transmission lines to due rust, I knew it was a matter of time before the fuel lines would go. In an attempt to make this truck as reliable as possible I tackled the lines before they left me on the side of the road.  While I had everything out from under the truck I cleaned, treated and coated the frame and underbody as well as changed the brakes hoses, shocks, front control arms, and front/rear diff and transfer case fluid.  I also added a steering stabilizer beasue it was super easy and cheap. The only unplanned thing I ran into was replacing the fuel pump because when I dropped the tank the inlet lines snapped due to rust (it turned out I couldn't get the lines off anyway they were so rusted).  Here are some of the pics of this project.

Rusted filter nuts


Rusty lines and frame


Rusty line by rear tank


Rusty rear suspension


Rusty front suspension
 
Spare tire holder, and rear fuel tank out


Main fuel tank out


What both tanks look like on my garage floor


What was left of the main tank pump


Front control arms out and frame cleaned


Front frame coated


Rear frame coated


Underside coated, I replaced the diff cover with an aluminum one later (shown in another post)


New control arms, shocks and brake hoses.


New and old shocks


Added steering stabilizer, this was super simple. 1: Buy steering stabilizer kit. 2: Buy 2.5" long 1/2" diameter bolt/nut. 3: Bolt onto bracket already on the truck.
 
I live in salt central, had my '04 AV undercoated but brake lines rusted thru and replaced the rotors twice due to rust before 50,000 miles. The two most convenient car washes I used closed so I got lax.

I'm from Michigan, after they salt the roads I clean off the surface a bit but concentrate on the underbody. You start under the wheel wells/fenders and spend most of your time spraying stuff underneath that you can't see.
 
Looks real nice with an Underhaul,but dont forget to rust proof the inside of the frame.Thats where it really counts.
 
Blazerteam said:
Looks real nice with an Underhaul,but dont forget to rust proof the inside of the frame.Thats where it really counts.

I did the entire inside of the frame when I had the tank and the lines out. I took off all the heat shields and did behind them too.  The truck was like this when I got it.  The previous owner didn't do any maintenance it seems.  I mostly use the truck for hauling my TT, so it should see very little winter salt, if any now. I keep my 203K mile 99 Jimmy around for my winter 4x4, which used to be my daily driver.  It actually rusted though its first line a couple weeks ago, so it will be going into the garage soon for an underhaul as well. 
 
Great job... Glad to see some keeping their AV on the road for a few miles...

I don't have to worry about rust as much but I still clean and touch up the frame undercoating and any painted areas as needed...
 
Nice work!  What did you use to coat everything underneath?  Also, did you strip them clean of rust or left some of the rust on and used rust converter coating?
 
I don't have to worry about rust on my Av, at least not on the drivers side.  My PS pump is leaking like a sieve and the entire drivers side frame is rustproofed.  I have the new pump to put in, just need to find the time and desire.  It is so much easier to just refill the pump every 2 or 3 weeks.
 
PerfectReign said:
:eek:

That is an amazing amount of work!! I've never seen so much rust.

You should have seen the underside of my 02 before I traded it  :laugh:

Honestly, you should see our '13.... I need to get on it and do something when I have the time... Not having a garage is the biggest thing keeping me from working on it.. We don't drive it a huge amount, so I have the time, I just don't have the facility.  :(
 
PerfectReign said:
as much as i hate california, i guess i'm glad i don't have rust.

My 02 has almost no rust underneath as well.  I think it is because it rains so much here that it keeps the underside clean and salt free.
 
I just want to know what the OP, TowWhite2500, used for his rust-proofing coating. TowWhite2500 where are you???  :help:
 
It will be interesting to see what TowWhite2500 uses.... I rustproofed my 2011 when it 4 years old using Krown (oil type spray through out the truck, and yes, they drill into the Avalanche). You need to do it each year, but has good results from what see from others. My buddy has an Envoy going on 15 years that is treated every year - not a speck of rust anywhere. It's about $130 an application. They have a big following here in Toronto. I just did this years application... I think I caught it early enough as not too much rust on the frame of the vehicle, and body panel are like I drove from the show room. I'll let you know in a few years what happening    :laugh: 
 
ngrome said:
Nice work!  What did you use to coat everything underneath?  Also, did you strip them clean of rust or left some of the rust on and used rust converter coating?

I used my angle grinder and a wire wheel anywhere it would fit and hand wire brushed the rest to remove the loose rust.  I then treated everything with Eastwood rust converter to attempt to stop/slow the rusting.  After that I used Eastwood's Rubberized Rust Encapsulator.  It was a little on the pricey side, but I have used cheaper products in the past with not as good results, I was willing to spend the extra in hope that it would last and not have to do it again.  Its been on for about 5 months now and still looks good, however the truck is driven little and sits in the garage when not used. 

http://www.jegs.com/p/Eastwood/Eastwood-Rubberized-Rust-Encapsulator-Undercoating/2112888/10002/-1
 
TowWhiteAv2500 said:
I used my angle grinder and a wire wheel anywhere it would fit and hand wire brushed the rest to remove the loose rust.  I then treated everything with Eastwood rust converter to attempt to stop/slow the rusting.  After that I used Eastwood's Rubberized Rust Encapsulator.  It was a little on the pricey side, but I have used cheaper products in the past with not as good results, I was willing to spend the extra in hope that it would last and not have to do it again.  Its been on for about 5 months now and still looks good, however the truck is driven little and sits in the garage when not used. 

http://www.jegs.com/p/Eastwood/Eastwood-Rubberized-Rust-Encapsulator-Undercoating/2112888/10002/-1

Thanks for the info, I researched that Eastwood and Corroseal are the two best products right now, but given the budget and time I have (trying to wrap up work on the truck with winter coming), I just picked up the Rust-o-leum equivalent of these since it was readily off the shelf at the local hardware store. I used Rustoleum on my other vehicle and it held up through the winter but I probably have to recoat when the weather gets warm.
 
Update to this, about a year after coating with the Eastwood it started to bleed rust though and went downhill from there.  It pretty much just flakes off now if you touch it.  I used the Eastwood rust converter on another vehicle and my father used it as well, both of these had different topcoats, but all with the same problem.  I think Eastwood changed the product over time, I have some older Eastwood paint used 20 years ago and it is still under the truck.

Since I now have another problem that ending up requiring the removal of both tanks I am working on doing this all over again with a different product.

Here is some pics of what it looks like now 2.5 years later, truck gets driven about 5000k a year if that and I don't drive it in the snow.





 
What i have learned about rust,is that you have to remove all the rust..and by that,it means all the brown spots in the metal..so sandblasting is the real deal here..and then apply 2 component primer and paint.Other methods and paint may work for awhile,but rust never sleeps.

Im actually planning of taking the whole frame off the truck,and having it sandblasted.As there is no other way of getting it done correctly.I have spent a week just recently taking care of thr rust in the quarter panel area,and while doing this,i found a bad spot in the frame..the rubber bushings that are between the frame and body,has been holding water and salt,which have made the metal rusting out in the frame..i have fixed the one i found,but there are probably more of this,if i remove the frame.
 
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