After July 1943, the appliqué armor bosses on the hull side of the M10A1 were deleted as the armor kits were never manufactured. This meant that some M36s had the redundant bosses, while others did not. The M36 initially retained the M10A1's "stirrup" gun rest on the rear hull; crews were unhappy about the lack of a proper travel lock for the 90 mm gun, and many improvised their own from travel locks taken from tanks. As the massive muzzle blast of the 90 mm gun obscured the crew's vision and reduced the rate of fire, a double-baffle muzzle brake was fitted to all vehicles after the first 600, beginning in early November 1944. A proper folding travel lock better-suited to the 90 mm gun was added to the rear hull at about this time. The gun itself was also modified with a better equilibrator and more powerful elevating mechanism.