Originally Posted By: supton
Pretty sure the "don't tow in overdrive" dates back to older 4spd autos, some of which had weak gears, but most of which tended to run unlocked convertors near stall speed, generating lots of heat. I'm guessing today's smaller motors simply spin faster when loaded, unlike yesterday's motors which could (and would) grunt down and get the job done--but unfortunately at a bad rpm for a TC.
Even after it downshifts it would pretty much immediately lock the TC anyway, so there wasn't a whole lot of slip going on.
Pretty sure the "don't tow in overdrive" dates back to older 4spd autos, some of which had weak gears, but most of which tended to run unlocked convertors near stall speed, generating lots of heat. I'm guessing today's smaller motors simply spin faster when loaded, unlike yesterday's motors which could (and would) grunt down and get the job done--but unfortunately at a bad rpm for a TC.
Even after it downshifts it would pretty much immediately lock the TC anyway, so there wasn't a whole lot of slip going on.
