[1] In 1969 Tatra decided to modernize the existing T138 model with a number of improvements and design changes.

Designers were tasked with the requirements of increasing engine power, vehicle speed and reliability as well as meeting stricter noise and emission regulations.

The fuel injection pumps featured different types variable or combination governors depending on the vehicle application.

The main gearbox was located behind the cabin and connected to the engine clutch housing via a short uni joint shaft (this design enables the so-called flat floor cabin) which was bolted together with the auxiliary gearbox to the backbone tube and formed the main part of the chassis structure.

The vehicle featured an independent auxiliary cab heater and included cyclone pre-cleaners mounted on the front mudguards.