Dating Minor CJ-3A Changes
Prefix Vehicle Serial Number Engine Serial Number Description Source Notes
CJ-3A 10755
Radiator hoses length change to clear governor belt Service Bulletin 49-7


3J10503 Crankshaft oil slinger gasket discontinued Service Bulletin 49-7


3J13984 Huglock connecting rod nut adopted Service Bulletin 49-7
CJ-3A 13639
PTO rear gearbox ratio changed Service Bulletin 49-7


3J15478 Huglock connecting rod nut change canceled Service Bulletin 49-21


3J16367 Piston fit clearance changed Service Bulletin 49-21



Clutch release lever opening enlarged Service Bulletin 49-27 "Bulletin dated June 14, 1949"
CJ-3A 21656
Steering bell crank shaft shortened to clear side mount rad. Service Bulletin 49-28
CJ-3A 14954
New type Monroe front shocks Service Bulletin 49-34


3J25610 Oil pump gasket change Service Bulletin 49-34
CJ-3A 37549
New type front axles (no axle nut on driving flange) Service Bulletin 49-53
CJ-3A 11890
Transmission to bellhousing gasket eliminated Service Bulletin 49-57
CJ-3A 29511
Transmission oil retaining washer eliminated Service Bulletin 49-57
CJ-3A 29257
New style gas line and clips to PCV line Service Bulletin 49-57
CJ-3A 31254
Spare tire stabilizer block added Service Bulletin 49-57
CJ-3A 31374
New radiator inlet hose Service Bulletin 49-57
CJ-3A 32429
Novi Governor adopted as standard accessory Service Bulletin 49-57
CJ-3A 32207
Accelerator floor seal part change Service Bulletin 49-59
CJ-3A 33961
larger draw bar bolts and reinforcement plates added Service Bulletin 49-59
CJ-3A 37549
Front axle shaft outer nut and lock washer eliminated
1965 Universal Service Manual
CJ-3A 43461
clutch lever hole cover adopted Service Bulletin 50-8
CJ-3A 43981
new voltage regulator Service Bulletin 50-8
CJ-3A 43461
new clutch control ball stud and bellhousing Service Bulletin 50-8
CJ-3A 46332
fuel tank gauge gasket change Service Bulletin 50-14



timing marks added to front pulley and timing cover Service Bulletin 50-14


3J45420 water pump change Service Bulletin 50-14 see 51-20



Auburn clutch assy adopted Service Bulletin 50-31
CJ-3A 48537
ignition coil Auto-Lite CR-6009 adopted Service Bulletin 50-31


3J50705 piston head thickness increased Service Bulletin 50-31
CJ-3A 51411
new type fuel pump Service Bulletin 50-31
CJ-3A 46358
improved steering column bearing Service Bulletin 50-31



new oil filler tube for generator clearance Service Bulletin 50-37
CJ-3A 57711
new air cleaner hose clamp Service Bulletin 50-40
CJ-3A 61403
starter rod attachment change Service Bulletin 50-40
CJ-3A 53768
taillight change from steel stamping to zinc die casting Service Bulletin 50-40
CJ-3A 62488
Front axle drive pinion spacer eliminated 1965 Universal Service Manual
CJ-3A 62488
rear axle differential change Service Bulletin 51-1
451-GB1 23945
redesigned rear drawbar Service Bulletin 51-9
451-GA1 10002
fuel line changes due to possibility of some Carter pumps Service Bulletin 51-10
451-GB1 28134
fuel line changes due to possibility of some Carter pumps Service Bulletin 51-10
451-GC1 10044
fuel line changes due to possibility of some Carter pumps Service Bulletin 51-10
451-GD1 10101
fuel line changes due to possibility of some Carter pumps Service Bulletin 51-10
451-GA1 10002
higher capacity ignition switch Service Bulletin 51-10
451-GB1 25992
higher capacity ignition switch Service Bulletin 51-10



steel upper radiator tanks Service Bulletin 51-14 8-Apr-51
451-GA1 10002
new rear shocks Service Bulletin 51-20
451-GB1 25684
"new rear shocks, some old style used after this serial #" Service Bulletin 51-20
451-GC1 10002
new rear shocks Service Bulletin 51-20
451-GD1 10002
new rear shocks Service Bulletin 51-20
451-GA1 10002
new front shocks Service Bulletin 51-20
451-GB1 27691
new front shocks Service Bulletin 51-20
451-GC1 10003
new front shocks Service Bulletin 51-20
451-GD1 10003
new front shocks Service Bulletin 51-20
451-GB1 32192
7 psi radiator cap replaces 4 psi Service Bulletin 51-20
451-GC1 10101
7 psi radiator cap replaces 4 psi Service Bulletin 51-20
451-GD1 10063
7 psi radiator cap replaces 4 psi Service Bulletin 51-20
451-GA1 10002
hard steel brake backing plate bolts Service Bulletin 51-28
451-GB1 34029
hard steel brake backing plate bolts Service Bulletin 51-28
451-GC1 10063
hard steel brake backing plate bolts Service Bulletin 51-28
451-GD1 10101
hard steel brake backing plate bolts Service Bulletin 51-28


3J90098 head gasket change Service Bulletin 51-28


3J158187 Bellhousing change 1965 Universal Service Manual possibly after the end of 3A production


3J161344 Hardened exhaust valve seat inserts installed 1965 Universal Service Manual possibly after the end of 3A production


3J1366871 Timing gear oil jet size change from .070 to .040 1965 Universal Service Manual possibly after the end of 3A production

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