Back in the late seventies and early eighties, the company I worked for made 8-track raw decks for the Ford Motor Company to put in their automobile radios.
My partner and I were the line techs and became expert at all sorts of things with this format. Sometimes we would sit at the end of the line with our own test set-ups to identify particular problems with the decks.
I remember that shortly after we started there (both on the same day), they were having problems with flutter and the combined wisdom of the place was that it was the belts. Trouble was was that a lot of these decks were rejected time after time after the belts were replaced. They were all sitting in roll-around shelves and they didn't know what they were going to do with them.
We set up at the end of the line and analyzed each reject deck and were able to tell whether it was the belt, flywheel bearing, tape stripper, etc. that was the cause. A guy came down the line one day and grilled us about how we were so sure such and such caused the flutter. I guess we were kind of smart-assy with our answers (the key was the percentage of flutter and cyclic action) and when he walked back up to the office, one of the line gals said "Do you guys know who you were talking to?" We just thought he was maybe some production engineer. She said, "That was the plant manager" and we thought "Oh oh, there goes our jobs." Instead, after all of these shelves were cleared of reject decks (having been repaired and passed) within a week, we both got promoted.
Turned out that he was a no nonsense kind of guy and liked our gung-ho approach.
Anyway, when the company closed the plant here in 2001 and I lost my job, they let me keep a complete quadraphonic deck/radio that I had brought back from Toronto years earlier. I have yet to hook it up though.
I once had a 8-track set-up in my car with an amp, 8 inch woofers, etc. and a friend of mine couldn't believe it was 8-track. He said, "It's all there." Of course, I made my own tapes from test tapes we had that had gotten out of spec. The mechanism in these was very good, unlike the dreck of most commercial tapes. I still have all of these.
The key to the longevity of an 8-track is the tension on the tape. Too often, in commercial tapes, the tape pack tightens up and the tension gets too high and breakage occurs. You can fix this by undoing the splice, unwinding the tape a few turns, resplicing, and turning the pack until the slack is absorbed by the pack.
Doug