>>714870809
>>714871359
From some other site:
>It’s a Dana Spicer T-Series 20-Speed Transmission. It’s found in a number of heavy trucks from the 1960’s forward.

>It’s a joke related to old versions of semis/18 wheelers/tractor trailers based on them having two transmissions at once. It was born back when most transmissions were only 4 gears back in the 60s-70s, so instead of making one transmission that had enough gears for the proper acceleration of the weight of a typical semi, they had one 4-gear transmission that fed into a second transmission that also had 4 gears, so the semi truck driver had to shift two transmissions to get along on his way.

basically being a semi truck driver in the 60s must have been confusing as fuck.