The 155mm GMC M40 used the HVS suspension system, and spare track blocks for the T84 tracks are stowed on the hull front on each side of the gun travel lock. The drivers' cupolas can be seen above the spare track. The late-production Sherman features include the single-piece, sharp-nosed final drive and differential cover. Although the vehicle is wider than the Sherman tank, note that the final drive and differential cover is the same, leaving a space between it and the tracks.
This rear view shows the large stabilizing spade that steadied the vehicle during bombardment. A working platform for the gun crew is folded up behind the spade; this came down over top of the spade when the vehicle was ready to fire.
A cross-section of the hull is shown here. Note the holes for the bolts to attach the final drive and differential housing; these are angled forward to make up for the steeper slope of the propeller shaft engendered by moving the engine forward. (Picture from TM 9-747 Feb 1945.)
The engine doors, grilles, and stowage are shown here with the vehicle facing to the right. (Picture from TM 9-747 Sep 1947.)
The engine is shown here installed. The vehicle is facing to the left, and the rear of the driver's cupola and the ventilating blower situated between the drivers can be seen on the left of the image. (Picture from TM 9-747 Feb 1945.)
The rear of the installed engine is detailed in this picture. (Picture from TM 9-747 Feb 1945.)
An exploded view of the engine's clutch and fan assemblies is shown here. (Picture from TM 9-747 Feb 1945.)
Parts of a steering brake are labeled in this image. (Picture from TM 9-747 Feb 1945.)
A horizontal volute suspension spring bogie and the different types of return roller are diagrammed here. The road wheels were 20.5" (52.1cm) in diameter, while the dual and single support rollers were 13.5" (34.3cm) and 10" (25cm), respectively. The normal free height of the volute springs was 14" (36cm), but once assembled they were reduced to ~10" (~25cm). The springs had five active coils each, and their maximum outside diameter was 8" (20cm). (Picture from TM 9-747 Feb 1945.)
The gun cradle was provided with a traveling lock in addition to that found on the gun tube. The clutch lever pedal hook allowed the crew to release the brake which locked the elevating mechanism. Ammunition racks can be seen at the front corners of the fighting compartment. (Picture from TM 9-747 Sep 1947.)
The elevation handwheel on the right side of the cradle and the elevation brake lever are highlighted here. (Picture from TM 9-747 Feb 1945.)
The traversing handwheel on the left side of the cradle and the traversing brake lever are shown here. The traversing brake handle was released by rotating it counterclockwise. (Picture from TM 9-747 Feb 1945.)
The breech of the 155mm gun M2 is shown here. The weight of the complete weapon was 9,595lb (4,352kg), the tube was 277.37" (704.52cm) long, and it could fire a high-explosive shell 25,715 yards (23,513m). (Picture from TM 9-747 Sep 1947.)
The firing mechanism is diagrammed in this picture. A primer was inserted into the breechblock under the firing mechanism, the percussion hammer locking pin was released, and a sharp pull of the lanyard sent the percussion hammer into the firing pin, igniting the primer and firing the ordnance. (Picture from TM 9-747 Feb 1945.)
The winch for the rear ramp is shown here. A. Ramp lock pin. B. Sheave. C. Cable. D. Drum. E. Brake band. F. Brake lever. G. Spring-loaded lock pin. H. Pinion gear housing. J. Ratchet. K. Crank. L. Portable fire extinguisher. (Picture from TM 9-747 Sep 1947.)
The sights for the 155mm GMC M40 and 8" HMC M43 were the same except for the direct-firing telescopes, which featured different internal reticles for their respective ordnances. (Picture from TM 9-747 Feb 1945.)