1957-1993 Dodge Dana 70 Rear Axle Identification IDN-140

1957-1993 Dana Spicer Model 70 Rear Axles in Dodge 200, 250, 300, and 350 series trucks plus many Motorhome and Van chassis models  have a Bill of Material Number (BOM) that is either stamped on the rear face of the right axle tube or embossed on a Build Tag (red arrow) attached to the differential by two of the differential cover bolts. Effective in the late 1960's, The BOM number is a 6 digit number beginning with a 6 plus a dash number (ex: 603651-3). They can be used to determine not only the axle model, but also what components the axle was originally built with. We often ask for this number to insure we provide you with the exact parts you need for your truck.

For pickup smaller van/motorhome chassis models, Dodge used several different standard versions  of the Model 70 rear axle including the Model 70, 70B, 70-U, 70-2U, and 71 (all with 3-13/16" OD Diff Bearing Cups), The larger motorhomes models typically have a Model 70HD (4-1/8" Diff Bearing Cups). Over the years, changes were made in wheel bearings, axle shaft splines, inner pinion bearing size, pinion spline, and year/model specific equipment. Towards the end of production for this series of axles, Rear Anti-Lock Brakes were added, but all axles of this era will have drum brakes.

All 1968 to 1984.5 Dodge Model 70 rear axles will have a BOM that starts with "603. 1984.5-1993 axles will have a BOM that begins with "605". Each different BOM number signifies an engineering part change which may be minor or major and may involve one or more parts. The dash number indicates the axle ratio and differential type (open or locking). Unfortunately, these tags are often missing on trucks that had prior differential service.

1968-1993 Dodge Dana 70 Rear Axle Bill of Material Numbers  (Motorhome and Van BOM Numbers are italicized):
1968-1971: 603018, 603019
1973-1975: 603242, 603285, 603341, 603346, 603377, 603378, 603515, 603547 
1976-1979: 603396, 603649, 603396, 603547,603651, 603652, 603653, 603695, 603696, 603841, 603872, 603955
1980-1984:c 603653,603916, 603918, 603955, 603995, 603997, 603998  
1984.5-1985: 605158, 605192, 605214, 605215, 605235, 605269, 605270
1986: 605158, 605235, 605269, 605270
1987: 605311, 605313, 605513,
1988: 605311, 605313, 605386, 605513
1989: 605311,605312, 605313, 605373, 605386, 605407, 605408 ,605513
1990: 605311, 605312, 605313, 605373, 605386, 605407, 605489, 605513
1991: 605508, 605509, 605510, 605511, 605512
1992: 605508, 605509, 605510, 605511, 605512, 605514, 605522
1993: 605508, 605509, 605510, 605511, 605512, 605514, 605522