I have seen these period of trucks with severe rusted rear wheel arches. I always wondered why the wheel arches rust from the inside out and how to prevent it. Some trucks of the same vintage have severe rust thru and others have no rust.

My truck is presently rust free. How does it happpen and what can be dont to prevent it?? How does the moisture and dirt get into the inner wheel arch/fender?? Thur the stake holes?? Where?? How to wash it out if it does??

I was under the truck bleeding the rear brakes and noticed that the inner fenders are two piece and that the two halves overlap and that this overlap is open--there may be spot welds--but it is possible for water and salt to get into the inner fender wheel well opening and roll down to the inner wheel well arch from the inside andjust stay there and cause rust from the inside. It would also explain why Broncos have the same rust above the rear wheel arches--and the Broncos have no stake holes.

Woulld it be a good idea to seal this overlap openings of the two inner fender well panels --and keep moisture and salt out of the inner wheel arch or would it cause the moisture not to ventilate and cause more inner rust??i bead of seal along the edges of this longitudinal inner fender panels would seal the inner fender well from moisture and salt.

I love my truck and dont want to see it get this cancer and rust from the inside out. This would be a very expensive thing to fix when it happens. It gives the Chevy guys reason to wonder about the durability of these Ford trucks and ruins these trucks for future owners.

 

when a truck gets washed, the lip inside the rear wheel does not, and dirt collects there. then over time the dirt retains moisture, letting rust start. the rust torn to rot. the rot then penetrates from inner to outer metal. then it just spreads like wildfire. the proper way to avoid this series of events is to thoroughly wash both outside and underside of the truck, and keep the inner lip of the rear fenders clean and dry.

 

Good point about wheel well lip rust. When I bought my 12 year old truck --that was the first thing that I checked by running my hand along the inside of all of the wheel arch lips checking for rust. And I take a wet terry clothe and use it to clean the inside top of all of the wheel well lips when washing the truck.

But what worries me is that I have seen these trucks with outer fender rust and no rust of the inner fender well lip! And I have seen rust that is above the area of the wheel well lip.The rust must start on the inside of the outer fender on at least some of these trucks. There must be a source of moisture or water that gets into the inner fender area. Unseen. The lip isnt the source of the original rust I believe.

 

tjc transport,

I feel guilty now, I better go wash my Bronc.
after somemore pumpkin pie, LOL!
phoneman91,
as in the other forum, keep the areas clean.

I saw transport had responded, so I wanted to read what he thought.
I agree with him.

 

crap comes down through the stakebed holes and gets stuck and holds moisture.

rust is the result.

frederic wrote about this last year when he was repairing his rusted wheelwells.

 

I understand about wheel well lip rust. But most of the rust thru on these trucks are centralized about 2 or more inches above the top of the rear wheel well opening--and not centralized at the wheel well lip. Check out these trucks on Ebay--and you will see this time and time again.

 

I thought this also--that the stake holes were the source of the moisture and dirt. But Broncos have the exact same problem--and Broncos have no stake holes. The source of this moisture would seem to be the overlapping open area between these two inner fenders . Look up at the highest point of the inner fender and you will see this open gap of this overlap of inner fender panels. I cant believe that Ford made the inner fender this way.

 

My FSB in not rusting thru- but I will take a look- If there is a spot weld there, that could be a problem. A scratch during manufacture could cause rust too.
I will look at my truck to see.

Remember, cars are ment to last as long as your payment plan does, 5-7 years.
How can auto makers make money if an auto lasted 20 years LOL!

Even in business- machines are to be replaced after 7 years- everything gets older and wants to return back to its original form........dust! think about it

 

is the area in question towards the middle of the upper wheelwell. i saw a sheet metal lap- that has a coulpe of C notches in it. the area is parllel to the ground?
not vertical correct?

I see some spot welds in the area- raw metal from welding process could be the culprit.

any thoughts?

 

I think that we are both referring to the same area of the upper inner fender. The inner metal fender is in two halves---one outer and one inner. And the two halfs are overlapped and spot welded. This overlap is open and would allow water and salt to enter the inner fender and collect on top of the wheel well arch and stay there and cause rust.

I am suggesting that this open overlap of the two halves of inner fender be sealed. This overlap isnt normally visible--I was laying on my back when I first noticed this overlap --the axis of which is from front to back of the truck .

 

Well, my truck (94 F150) had major rust holes in the rear wheel well arches, and I had to completly replace both rear and one front with patch pannels. Mine is an XLT and I discovered that the chrome stripping that runs along the wheel well arch actually collects salt, mud, moisture, etc... When I replaced my arches, I put a nice thick layer of fiberglass on the back on the clean, new wheel well, and I am hoping that this will stop any rust from forming in the long run =)

 

when driving the wheels will also splash some crap up into the void between the inner and outer fenders. the splash guards leave alot to be desired.

 

My truck did have splash guards, but the previous owner let them hang down and rub the tires, causing holes to be formed, and these allowed mositure and crap to go up, but not come down, which made for alot of new metal and bondo

 

The answer is to buy a few pair of patch panels and store them in the attic, then every 10 years cut out the arches and weld in new panels and not worry about it for another 10 years.

 

wow some very good information in here! I have always wondered why too. now i am goin to have to wash under my truck