Dana 44 Differential Tech 1953-1993

Dana 44 Open Differential Tech Notes for 1953 to 1993 Axles without Axle Shaft Thrust Block or Vacuum Controlled Central Axle Disconnect: The differentials discussed here would be primarily found in front axle applications for all years or in 1970's International and Jeep flanged semi-float rear axles without an axle shaft thrust block. These popular diffs were used by Dodge, Ford, GM, International, Jeep, and Studebaker for many front/rear axle applications from 1953 to 1993. During the 40 year production run of the original Dana 44 differential, there were two significant engineering changes, both of which occurred in the 1960s. Details of these changes and other technical details can be found in the Tech Notes below.

Dan the Gear Man® Tech Note 1 (Axle Shaft Diameter and Spline Count):
Up until 1960, Dana 44s had 1-1/4" 19 spline axle shafts. For 1960, the new factory GM 4x4s had Dana 44 front axles with 1-5/16" 30 spline axle shafts. For most vehicles, 19 spline shafts were replaced by the stronger 30 spline shafts between 1966 and 1970. The approximate change dates for 19 to 30 spline are:
Ford: F100 1966, F250 1967
GM: GM parts books only list 30 spline shafts for 1960 on. GM used Timken front axles prior to 1960.
Dodge: 1969
IHC: I am not sure of the changeover date, but it was prior to 1967.
Jeep: Front 1970, Rear 1969

Dan the Gear Man® Tech Note 2 (Inner Diameter of Diff Bearing):
During the mid 1960's the differential side bearing inner race diameter changed from 1-11/16" to 1-51/64". As far as I have seen, the bearing change roughly coincided with the axle shaft change except for GM. I believe GM started using the large bore bearing in 1964, however one GM parts book shows ONLY the large bore bearing from 1960-on, while aftermarket sources have change dates ranging from 1964 to 1968.

Dan the Gear Man® Tech Note 3 (Ring Gear Flange Offset):
There are two different ring gear flange offsets for 1950's to 1993 Dana 44 front axle and most rear axle applications. Lower numeric gears (faster) have more gear teeth and larger diameter pinion heads compared to higher numeric (slower) gear sets. A 2.72 gear set has 18 pinion teeth. The pinion for 5.38 ratio set only has 8 teeth. Consequently, the ring gear needs to be farther from the pinion center line for fast gears and closer for slow gears. While the thickness of the ring gear can be increased or decreased to a certain extent to compensate for different pinion gear diameters, there is a practical point where the ring gear would become too thin or too thick to use one differential offset. With these Dana 44 axles, there is QU40633 "Fast" differential case for 2.72-3.73 gear sets and QU40635 "Slow" Case for 3.92-5.89 ratios. (These are 30 spline case assemblies)

Dan the Gear Man® Tech Note 4:
When working on axles built prior to 1970, it is always best to verify what components you have before ordering parts. It is not uncommon to find older axles with non-stock parts or even axle assemblies from other years/makes/models swapped into a vintage vehicle. For example, we have a front axle taken from a 1965 Ford F100 that has the 1965 F100 brakes, spindles, hubs, and outer axles attached to a 1967 F250 housing, steering knuckles, differential and inner axle shafts. The other reason to always verify what you have is sometimes my memory of what I worked on 35 years ago is not perfect!

Dan the Gear Man® Tech Note 5:
A Ring Gear Bolt is a torque-to-yield type fastener and is designed to be used once and only once. For strength and safety, DO NOT reuse ring gear bolts. The Dana 44 ring gear bolt number is: QU40209, quantity required is 10.

Dan the Gear Man® Tech Note 6:
Related items for Dana 44 Diffs:
QU50576 Differential Bearing and Seal Kit for 1993 and older axles
QU40177 New Genuine Dana 4.09 Ratio Gear Set with Pinion Bearings and small parts
QU40215 Pinion Seal to 1993
QU40028 Inner Pinion Bearing Slinger
QU40448 Inner Pinion Oil Baffle
QU40002 Outer Pinion Slinger
QU40311 Diff and Pinion Shim Kit
QU40009 Pinion Lock Nut
QU40010 Pinion Yoke Washer
QU90009 Axle Service Pack with Gear Marking Compound, Threadlocker, RTV Sealant, Brush
QT1216 Differential Housing Spreader
QT1044 Inner Pinion Bearing Installer
QT1812 Outer Pinion Bearing Cup Installer
QT1815 Inner Pinion Bearing Cup Installer
QT1097 Differential Master Bearing Set
QT1115 Differential Side Bearing Installer
QT1035 Diff Press Plate

Related Pages

Chevy/GMC Dodge Ford IHC/Jeep
GM Dana 44 Closed Knuckle Front Axle 1960-1969 Page Dodge Dana 44 Closed Knuckle Front Axle 1957-1971 Page Ford Dana 44 Closed Knuckle Front Axle 1959-1975 Page IHC Dana 44 Closed Knuckle Front Axle1953-1975 Page
GM Dana 44HD Closed Knuckle Front Axle 1962-1969 Page Dodge Dana 44HD Closed Knuckle Front Axle 1963-1971 Ford Dana 44HD Closed Knuckle Front Axle 1961-1975 Page IHC Dana 44HD Closed Knuckle Front Axle 1956-1972 Page
GM Dana 44 Open Knuckle Front Axle 1969-1972 Page Dodge Dana 44 Open Knuckle Front Axle 1972-1975 Page Ford F-250 Dana 44 Open Knuckle Front Axle 1976-1979 IHC Dana 44 Open Knuckle Front Axle 1971-1980 Page
GM Dana 44 Open Knuckle Front Axle 1973-1981 Page Dodge Dana 44 Live Spindle Front Axle 1974-1979 Page   Jeep Dana 44 Closed Knuckle Front Axle 1957-1973 Page
  Dodge Dana 44 Open Knuckle Front Axle 1980-1984 Page   Jeep Dana 44 Open Knuckle Front Axle 1974-1991 Page
  Dodge Dana 44 Open Knuckle CAD Front Axle 1985-1993 Page   IHC Dana 44 Rear Axle 1950-1980
      Jeep CJ Dana 44 Rear Axle 1972-1975 and 1986
      Jeep J-Series Dana 44 Rear Axle 1972-1991


Chevy and GMC (Front Axle):
1973-1979 K5 Blazer, Jimmy, K10/K15

Dodge (Front Axle):
1957-1983 W100, W150
1969-1993 W200, W250 with Dana 44 axle
1974-1983 Ramcharger, Trailduster

Ford (Front Axle):
1959-1982 F100, F150
1959-1977.5 F250 Regular Cab
1971-1982 Bronco

IHC (Front Axle):
1953-1975 1100, 1200
1974-1980 Scout

IHC (Rear Axle):
1974-1980 Scout

Jeep (Front Axle):
1957-1965 FC150, FC170 J-Series Trucks
1970-1988 J-Series Truck
1974-1991 Cherokee, Wagoneer

Jeep (Rear Axle):
1972-1975 CJ5, CJ6
1974-1985 Cherokee, Wagoneer, J10