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.
Need More Info? Use the handy Links below to access over 40 years of Dan's product and vehicle specific Tech Notes to easily get the information you need for your vehicle's repair, maintenance, or upgrade project!
Dan the Gear Man® Tech Notes:
Axle Shaft Diameter and Spline Count
Inner Diameter of Diff Bearing
Rear Gear Flange Offset
Verify Components
Ring Gear Bolts
Matching Parts
Applications
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
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.
Tech Note 3: Rear 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)
Tech Note 4: Verify Components
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!
Tech Note 5: Ring Gear Bolts
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.
Tech Note 6: Matching Parts
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
QT1032 Differential Housing Spreader
QT1044 Inner Pinion Bearing Installer
QT1812 Pinion Bearing Cup Installer
QT1115 Differential Side Bearing Installer
QT1035 Diff Press Plate
Applications
Chevy and GMC (Front Axle):
K20/K25/K2500: 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980
K5 Blazer, Jimmy, K10/K15: 1973, 1974, 1975, 1976, 1977, 1978, 1979
Dodge (Front Axle):
W100, W150: 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983
W200, W250 with Dana 44 axle: 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993
Ramcharger, Trailduster: 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983
Ford (Front Axle):
F100, F150: 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982
F250 Regular Cab: 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977.5
Bronco: 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982
IHC (Front Axle):
1100, 1200: 1953, 1954, 1955, 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975
Scout: 1974, 1975, 1976, 1977, 1978, 1979, 1980
IHC (Rear Axle):
Scout: 1974, 1975, 1976, 1977, 1978, 1979, 1980
Jeep (Front Axle):
FC150, FC170 J-Series Trucks: 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965
J-Series Truck: 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988
Cherokee, Wagoneer: 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991
Jeep (Rear Axle):
CJ5, CJ6: 1972, 1973, 1974, 1975
Cherokee, Wagoneer, J10: 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985