TM-9-2350-311-34-2 Maintenance Manual for Volume 2 M109 Cab Download
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TM 9-2350-311-34-2 1-15 DIFFERENCES BETWEEN MODELS Most of the differences among components of M109A2 and M109A3 howitzers concern the M109A3 model. There are 103 differences in the cabs of the M109A3 vehicle population. Variations among M109A2 vehicles and differences between M109A2 and M109A3 vehicles are minimal. M109A4 howitzers have updated hydraulic components and an added NBC system plus reliability and maintainability. M109A5 howitzers have been updated from the M109A4 models. In addition to all M109A4 updates, the M109A5 model also modifies the M185 cannon assembly to an M284 cannon assembly and M178 mount to an M182 mount. The maintenance procedures in this manual will call the mechanic’s attention to any differences in cab components which will affect the mechanic’s performance of direct and general support maintenance tasks. Where parts which must be re- moved or inspected differ significantly in appearance, a cutaway view will be used to show the alternate parts. Part differences not relevant to the direct and general support mechanic will not be mentioned or pictured. Below are some examples of cab component differences important to the direct and general support mechanic. Functional group and part Number of Variations How assemblies/Darts differ 00 Protective shields, race ring 3 All M109A2/M109A4/M109A5 ve- hicles have five protective shields. All M109A3 vehicles with three con- tact arms have four protective shields. All M109A3 vehicles with five contact arms have five protec- tive shields. Protective shields mount on race dif- ferently. Some M109A3 howitzers do not have a turret shield behind the commander’s seat. 01 Bearing assembly 2 02 Dust shield 2 02 Variable recoil assembly Some vehicles have 212 bearing balls mounted on 106 race ring spacers. Other vehicles have 213 bearing balls mounted on helical compression springs. M109A5 howitzers have added an extra retainer and replaced seals on dust shield. 2 M109A5 howitzers have replaced many seal configurations from kit 5910844 with dust boots. Also a re- coil nut modification has been add- ed to M109A5 vehicles. 1-37