Tumble Speeds
Yes, Whirlpool offered multiple tumble speeds on top-of-the-line and near-top-of-the-line models for a few years.
The motor had a cone-shaped pulley and a wide idler pulley. The mechanical shift mechanism positioned the belt to different diameter areas of the pulley for the available speeds. Instructions advised not to change the speed unless the dryer was running -- press Start first to get it going, then set the speed.
Three speeds were available:
- Fastest speed for large or bulky items such as sheets and blankets
- Medium speed for "normal" items
- Low speed for light-weight delicates
It was reduced to two speeds for the last year the feature was offered (the LDA-9800 series which is the gold pair in Reply #3).
The avocado dryer in Reply #6 is a 1974 LAE-8800, one step below top-of-line, still had 3 speeds. LAE-9800 would been the top-of-line for 1974, also had 3 speeds.
Note that the tumble speed selector is a different thing from earlier dryers that offered two drying speeds via a rotary control, usually labeled Super & Gentle. The drying speed control did not affect tumble speed, it changed the airflow rate via either shifting the blower belt on a dual pulley or a damper door in the exhaust (when the design was changed to a direct-drive blower).