Like many others, i was suffering the problem of rust marks on clothes, which ruins them for good.
We have a Frigidaire Gallery dryer, gas, front loading stacked in top of the washer, which is about 7 or 8 years old.
Turns out the top felt seal was worn out, allowing clothes to get stuck between the drum and the door where they would get the rust colored stain. I think this is fairly common. It also "ate" zippers and buttons.
To open the dryer up, you first want to remove 2 screws at the bottom of the front panel, they are covered by little plastic plugs that pop out. Then, go in through the top- you have to pop the lid up from the front, and it swings up like a car hood. from the top, you have to reach in and undo a screw on each side that holds the front panel to the body of the dryer. it's a little tricky.
After those four screws are removed, the front panel is held on by pressure clips, which you can reach from the top and squeeze so they 'let go'. As those release, the front panel will fall outward with the bottom still attached- there are two small pieces of metal at the bottom that the panel sits in. So you lift the panel straight up to get them off those two guides/hooks, and it's clear.
Next you'll want to shop vac the heck out the whole dryer interior. Mine was caked with dust and lint.
Step two is felt replacement. you have to use some muscle to tear the felt off the top of the door opening, which will leave a bunch of ripped felt stuck to the high temp glue. That's where the wire brush and the Goof Off come in. That stuff worked like a charm to remove every last bit of felt and glue.
Once clean and dry, apply the glue that came with the felt guide, set the felt in place (with those plastic pieces facing up), and hold in place for a while. I used plastic clamps to hold the felt in place for about 30 minutes while the glue set.
For good measure, i also replaced the dryer belt and the plastic ball joint that the drum sits in, but i don't think that was necessary. The belt may be a good idea, and to do that you remove the belt by popping it off the little plastic wheel under the drum first, then it'll be loose and you can remove the belt and put a new one on. (This is also a little tricky, take it one step at a time.)
Then put it back together in reverse order and you'll be done with those rust marks.
(Mine is working great)
Other Parts Used: