The location of the lint filter in a washing machine depends on the brand and model of the machine, and the owner's manual states where it is located. For instance, model RAX7245JQ0 of the Roper washing machine by Whirlpool has a lint filter located under the washer's agitator, while newer models of the same machine don't have a lint filter at all.
The model number WTW5500SQO unit of the Whirlpool top-loading washer line doesn't have a typical lint filter, but it does have a screen located underneath the agitator that often collects lint and other debris. The washer also features a drain filter that sieves the water entering and leaving the water pump.
Some lint filters are located around the top rim of the washing machine tub. If the lint filter is located in the rim, it is important to pull out the screen and remove any clumps of lint that have accumulated. Some lint screens are located inside the agitator itself. The cover of the agitator is removable for this kind of filter. In other cases, the lint trap is located at the very end of the washing machine's drainage hose.
Use a paper towel to remove lint from the screen, or brush the screen clean. Rinse the screen in hot water to remove any remaining lint, and then put the filter back. Clean the pump filter regularly for washers that don't have a traditional lint filter.