Once the instruction period was over Ramírez was relieved of his duty by Infantry Commander Miguel Ferrer Canet, who had previously led the 2nd Battalion of the 82nd Mixed Brigade.

When the large-scale republican attack against Teruel began in December, the 40th Division led by Andrés Nieto Carmona was made part of the 20th Army Corps, which carried on its shoulders the main weight of the offensive.

[4] On 31 December the much-battered brigade withdrew to the outskirts of Teruel for a break, entering the small town again the following day and holding its ground until the surrender of the last strongholds of rebel forces on 7 and 8 January.

[3] After weeks of intense combats, the survivors of the much depleted 84th Mixed Brigade were sent behind Republican lines to Mora de Rubielos for a time of much needed rest.

The rebel side, however, launched its vigorous mid-January 1938 counterattack and, lacking troops to put up an effective resistance, the Republican high command resorted to the desperate measure of recalling all available reserves, including the exhausted 84th Mixed Brigade, whose men barely had had time to recover.

[3] On 21 January the fate of the brigade was sealed when an effort by the remaining and spent troops of the disgraced unit to take the strategic hill known as El Muletón ended in catastrophic failure.

[3] At the onset of the Battle of the Ebro it already joined the end of July combats and took up the first line facing Vilalba dels Arcs, in the zone between La Pobla de Massaluca and Cuatro Caminos.

[3] There are no data, however, about its performance in the impending Catalonia Offensive, so that it probably fell apart before or during the chaotic northward rush that ended with the Republican military in the Northeast at the beginning of February 1939.