Panther (car buff name for Ford Crown Victoria/Mercury Gran Marquis/ Lincoln) has a tricky steering column with two U-joints under the hood between the steering box and the column proper. Steering had been getting sticky on mine, sticky moving toward un drivable. Gave the U-joints a good shot of WD-40, and finished them off with 3-1 oil. Vast improvement.
WD-40 is very thin and isn't much of a lubricant, it's more a rust proofer. It softens up the crud and soaks into the joints. The 3-1 oil follows the WD-40 and gives some lubrication.