The SU-76 was based on a lengthened and widened version of the T-70 tank chassis. Its simple construction made it the second most produced Soviet armoured vehicle of World War II, after the T-34 tank.
Crews loved this vehicle for its simplicity, reliability, and ease of use, although it was sometimes nicknamed 'suka' (bitch), 'Suchka' (little bitch) or 'Golozhopiy Ferdinand' (bare-arsed Ferdinand) for its layout which recalled the massive Porsche-designed German tank hunter. One famous crewman was Rem Nikolaevich Ulanov. In his younger days he was a mechanic-driver and later a commander of a SU-76. He and some other soldiers called their SU-76 Columbina after the female Renaissance Italian Commedia dell'Arte personage.
Design of the SU-76 began in November 1942, when the State Defense Committee ordered the construction of infantry support self-propelled guns armed with the ZiS-3 76.2 mm gun and the M-30 122 mm howitzer. The T-70 chassis was chosen for mounting the ZiS-3 gun, and was lengthened, adding one road wheel per side, to facilitate better gun mounting.
In the rush for fast completion of the order, a quite unreliable power plant was installed in the first mass produced SU-76s. It utilized two automobile engines (GAZ-202) mounted in "parallel", each track with its own engine. It was found to be difficult for the driver to control the two engines simultaneously. Moreover, strong vibrations led to early failures of engines and transmission units. The vehicle was completely enclosed by armour. After producing 320 SU-76s, mass production was halted in order to fix the problems. Two chief designers at the GAZ plant, N. A. Astrov and A. A. Lipgart, changed the power plant to the reliable T-70 design. The roof of the compartment was removed for better gun servicing. This modified version, called the SU-76M, began mass production in early 1943. The production halt and redesign was the reason for the introduction of the SU-76i as a temporary replacement for the SU-76.
After the pause, GAZ and two factories in Kirov and Mytishchi produced 13,932 SU-76Ms (the larger part of the order, over 9,000 vehicles, were built solely by GAZ). Mass production of the SU-76M ceased in the second half of 1945. In contemporary accounts SU-76Ms are often referred to in texts, public radio and TV broadcasting as SU-76s with the "M" omitted, due to their ubiquity in comparison with the original SU-76s. The SU-76M was withdrawn from Soviet Army service after the Second World War ended.