Just got my silver 02 "X" a few months ago, and the frame is in *very* good shape. The inside of the frame appears to have the usual surface rust and appears to be untreated from the factory. I bought a 10$ garden sprayer from Home Depot and filled it with about 3 quarts of used motor oil. I sprayed the inside of the frame as completely as possible, using every hole available. This is an old, old trick used on farms (Plows, tractors, tools)and whatnot for decades. The drippage was actually minimal and poses no threat to the environment, in case there are any tree-huggers here. The oil will do a good job of arresting any current rusting and prevent future rust for a long time. I will repeat once a year, just to be sure. Actually used less then a quart, as there is quite a bit left in the sprayer. I will POR-15 the outside shortly.
2002 Wrangler "X".
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