We have a good selection of commonly needed replacement parts for Dana 70 series rear axles used in 1973 to 1991 Chevrolet and General Motors 1 ton trucks, vans, van chassis, and motor home models. Dana 70 Heavy Duty (70HD) axles were used in both Single Rear Wheel (SRW) and Dual Rear Wheel (DRW) 1 ton pick and pickup based cab and chassis applications as an alternative to GM 14 bolt 10.5" rear axles. Conventional Van and Panel Van based models may have Dana 70B, 70U, or 70HD axles depending upon the year, Gross Vehicle Weight (GVW), and chassis model.
1973-1991 Dana Spicer Model 70 Rear Axles in Chevy and GMC 1 ton trucks trucks have either a Bill of Material Number (BOM) stamped on the back side of the right axle tube or a a Build Tag (red arrow) attached to the differential by two of the differential cover bolts (yellow arrows). The BOM number is a 6 digit number beginning with a 6 plus a dash number (ex: 605523-3). 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.
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.
Many Dana Axle have the model number cast somewhere on the cast iron differential housing. (Number is shown at near actual size.)
GM C and K trucks were not equipped with Dana 60 rear axles after 1972, however, some 1 ton vans did use Dana 60 Dual Rear Wheel (DRW) rear axles from 1973 to 1991 making it imperative that G30 DRW Chassis Van owners identify which axle they have before ordering parts. Not all Dana axles have the model number cast on the housing. It can be very difficult to tell a Dana 60 from a Dana 70, as they have nearly identical covers with exactly the same bolt pattern. One way to tell if you have a Dana 60 or Dana 70 is to measure the cover flange height (yellow arrow). The Dana 60 flange height is approximately 1" high. The Dana 70 flange height is about 1¼" high.
Dana 70 Rear Axle Bill of Material Numbers
|1973: 603354 (DRW)|
|1979: 603704 (DRW)|
|1980-1981: 605003 (DRW)|
|1982-1983: 605099 (DRW)|
|1984: 605099,605203 (DRW)|
|1985-1986: 605203 (DRW)|
|1987: 605305 (SRW), 605331 (DRW), 605345 (SRW), 605346 (SRW)|
|1988-1989: 605331 (DRW R/V Old Square Body),605345 (SRW), 605346 (SRW), 605397 (DRW C/K New Aerodynamic Body)|
|1990-1991: 605331 (DRW R/V Old Square Body), 605397 (DRW C/K New Aerodynamic Body)|
| Dana 70 Rear Axle Bill of Material Numbers
for 1973-1991 Chevy and GMC 1 ton Van Based
Chassis, Delivery, and Motorhome models
|1974: 603474, 603476|
|1975: 603536, 603537, 603546|
|1976-1978: 603657, 603703, 603704, 603753, 603881|
|1979: 603703, 603929, 603970|
|1980-1981: 605002, 605004, 605005, 605068, 605096|
|1982: 605002, 605117|
|1983: 605117, 605134|
|1984-1987: 605043, 605117, 605202|
|1988-1991: 605043, 605202, 605310, 605361, 605363, 605391|
Depending upon the year and vehicle model, variations in wheel hubs, axle width, shock/spring mounts, brake equipment, axle ratio, pinion yoke, and rear differential cover can make it difficult to find an exact fit Dana 70 replacement axle assembly for your vehicle. We rarely have whole axle assemblies available for vintage Dana 70 applications, but we will list any assemblies or housings we have below.
The outer Pinion Bearing and Cup is the same for all 1973-1991 Dana 70 Rear Axles in Chevy and GMC 1 tons. The Differential Side Bearings and Inner Pinion Bearings will vary on vans depending upon the year and wheelbase, but all the truck based models will use the same bearing numbers for all years.
QU50602 Timken® Dana 70B, Dana 70HD Inner Pinion Bearing For all 1973 to 1991 Chevy and GMC Dana 70B and Dana 70HD Rear Axles in one ton trucks and vans. More Info
QU40259 Differential Side Bearing Set For GM and Chevy 1978-1991 1 Ton Square Body Style Pickup with Dana 70HD and Dual Rear Wheels are original equipment quality replacements. QU40259 Kit includes two each Bearing Cups and Tapered Bearings. This Set DOES NOT fit van models with either Dana 70B or Dana 70U rear axles!
Please refer to QU40259 page for more details and ordering information.
The GM Dana 70 Rear axle uses steel rear axle flange gaskets to seal between the rear wheel hub and axle shaft. Early production axles also had a cut paper gasket for sealing between the rear cover and housing, but all later production axles were assembled with RTV sealant in lieu of a gasket.
QU42030 Hipro Dana 70 Differential Cover Gasket For Model 70 axles. Reusable Dana 70 High Performance Differential Gasket is a genuine Dana part
Dan the Gear Man® Product Note: Knowing how to do the job right the first time is half the battle. With our detailed, easy to read, and well illustrated technical publications, you get accurate service procedures, torque specifications, and tool recommendations.
TMC73CD 1973 Chevy Truck Factory Shop Manual CD
Proper lubrication and replacing damaged or worn small parts is often the difference between a first class, long-term repair and a short lived nightmare. In this section are the small parts and accessory items that do not neatly fit under our other parts headings.
GM used several different pinion yokes for 1973-1991 1 ton vehicles with Dana 70 series rear axles. While only two u-joint sizes were fitted (1350 and 1410), the yoke and retention hardware will vary depending upon year and model. Replacement yokes and most mid to late production factory yokes use either Spicer type u-bolts or strap/bolt kits to retain the u-joint, however, some axles with 1350 u-joints use GM hardware so you need to verify your hardware type before ordering.
1350 U-Joint: 1.187 cups, 3.625" overall installed width: Verify if GM or 1410 U-Joint: 1.187 cups, 4.187" overall installed width: All we have seen use Spicer type Strap and Bolt Kit
Sometimes, you just need one or two small parts to get back on the road. Between the small parts listed in this section and many others listed under part specific headings elsewhere on the page, we probably have that pesky little part you have to have but just can't find anywhere else.
Dan The Gear Man® Safety Note: Ring Gear Bolts are designed for a single use. They must be replaced after they are removed!Please refer to QU40086 page for more details and ordering information.
Early GM Dana 70 Full Float Rear Axles in truck applications used a Four Piece Double Nut/Double Washer setup for wheel bearing adjustment and retention. This was used on all 1974-1979 truck axles, most 1980 and some 1981 axles. (The four piece nut set may have still been used on some later 1980's axles for limited applications) Starting in 1980, a single Spindle Nut held in place by a solid Key and Retainer Ring appeared on some models and was phased in for all axles over the next year or two. Both nut types are quite reliable when properly installed. The same nuts were also used on van based models with 2" spindle threads.
Having the right tool for the job makes the work easier and faster, plus the correct tool will usually minimize the chances of wrecking parts. We offer many special tools made specifically for the Dana 70 rear axle in your 1993-1991 Chevy or GMC 1 ton.
QT1032 Differential Case Spreader
We stock original equipment type Wheel Seals and Timken® Rear Wheel Bearings for your Chevy or GMC Dana 70 series full float rear axle with 2" spindle threads. For 1 ton pickup based vehicles, all years and models use the same wheel bearings for both single rear wheel and dual rear wheel trucks up through 1991. Most van models with the Dana 70 will also use the same bearings and seals, however you will find some motorhome and special applications with different bearing and seal configurations.
Replace those pitted, worn out rear wheel bearings on your Chevy or GMC Single or Dual Rear Wheel (DRW) 1 Ton truck with the Dana 70HD full-float rear axle. The rear wheel bearings in these Dana 70 axles average about 125, 000 miles before requiring replacement. Torque King® Premium Rear Wheel Bearing and Seal Kits for your Chevy or GMC truck feature premium Timken® bearings and original equipment quality wheel seals because when it comes to rear wheel bearings and seals, only the best will do to safely support the heavy loads your truck hauls. To help you install these vital components properly, optional bearing cup and wheel seal installers are available. Why use makeshift installation methods that can damage precision surfaces when affordable tools are available to do the job right the first time?
QK8311 Rear Wheel Bearing Kit for 1973 to 2000 GM Full Float Rear Axles In 14 Bolt 3/4 and 1 Ton GM trucks. Includes 4 Timken Bearings and Cups, 2 Rear Wheel Seals, 2 Spindle Lock Washers, and Installation tools.
Please refer to QK8311 page for more details and ordering information.