In the late 1940’s, Argentina bought nearly 450 M4 Sherman’s from Belgium in many british variants, over 250 of them were the Firefly version, with the long barrel 17pdr gun.
In the late 1970’s, the Argentinian Army needed to modernize their armoured units. The TAM project was under way, but the border crisis with Chile required an urgent reinforcement until the TAM was operational and the Army ordered the modernization of 250 Shermans, mainly the Firefly version then in service. This program included a new engine and a new armament. Many versions of M4 in the argentinian service were used, and the Repotenciado (Lit; Upgraded) was born. Most of the Sherman Repotenciado are the british Sherman Hybrid Firefly IC, but it`s not the only version. The principal advantage in using the Firefly was the easy adaptation of the internal configuration to the new 105mm ammunition storage.
The modifications included the french Poyaud 520 diesel engine, french made 105 mm cannon, built under license in Fábricaciones Militares Río Tercero, and other minor improvements. These included a rear modification of the turret, with a counterweight for the new longer and heavier gun, four smoke grenade launcher, storage baskets and new positions for radio antennas. In the hull, the modifications was more extensive, the engine compartment was redesigned for the new Poyaud 520 diesel engine, the suspension was revised and upgraded, and the tracks are rebuilt. This project begun in 1976 and finished in 1978, just in time to be deployed during the border crisis with Chile, in december of that year.
A total of 252 Shermans in many versions are upgraded to ‘Sherman Repotenciado’ standard and the last vehicles stayed in service until 1994, when all the TAM VC medium tank were completely active in the I and II Brigadas Blindadas (1st and 2nd Armoured Brigades). Even now, in 2002, a few (12?) ‘Sherman Repotenciado’ are still in service for support roles with the URDAN mine roller.