Oh my gosh, yes. There are probably all sorts of "bee's wings" (tiny bits of transmission) clogging the filter. You change your oil and filter to get rid of the microscopic bits of engine debris... your tranny needs the same thing. When you check the transmission fluid, it should always be bright red, clear, and sweet smelling. If the fluid is brown, cloudy, or has a burnt smell, it's way past due for a change, and damage may have already been done. Especially if you do a lot of city or stop-and-start driving, you need to change transmission fluid and filter every 30,000 miles or so. I do a lot of towing, so I adhere to this recommended interval as well.