Our 16-year-old Montgomery Ward dryer, Signature 2000 model # FFT-7589-80B, has developed a very high-pitched squeak that starts a minute or so after we start it up. I have replaced the felt pad with spacers (between the door and the drum) to no avail.

The front panel is a solid panel, and the mechanisms (motor, rollers, etc) all seem to be in the back. In the front is the door and the lint duct, but no rollers or anything visible below the drum.

We have lost the manual years ago for this, but I'd really like to try to fix it on the cheap rather than spend hundreds for a new one.

Any suggestions as to what may be squeaking, how to access it, check it, and replace it?

First, congrats on getting 16 years out of a dryer. Montgomery Wards did not last as long as that dryer. There is a large fan belt and idler pulley going around the drum. Some manufacturers even replaced the pulley with a nylon/teflon surface for the belt to slid over. You can check both by removing the back of the dryer but some models open by prying off the top of the unit. If you are not especially handy it might be a good idea to call in a repair person.