Dana 44 & Dana 44HD TTB Front Axles

In 1980 the Bronco went from a straight Dana 44 front axle to what Ford calls the Twin Traction Beam front suspension. The TTB system is Ford’s 1980-1996 version of an independent front suspension. Mechanically, the TTB axle is similar to a straight axle, but instead of a solid axle tube, the differential and steering knuckles are attached to beams. The inboard ends of the beams are attached to a frame-mounted crossmember by a bushing, while the outboard ends support the steering knuckles and are attached to the frame through the springs and radius arms.

Dana 44 TTB:

The Dana 44 TTB (Twin Traction Beam) was used in the front of Ford F-150’s and Ford Bronco’s from 1980-1996. Production on the Ford Bronco completely ceased after 1996, and the Ford F-150 switched from the Dana 44 TTB to an 8.8 IFS front axle in 1997.

The Dana 44 TTB was a variation of the reverse cut solid axle Dana 44 used by Ford. It appeared in the F-150’s and Bronco’s with coil springs.

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Dana 44HD TTB (Medium Duty):

The medium version was the Dana 44HD TTB used on light duty (under 8500# GVW) Ford F-250’s from 1980-1986. This system uses leaf springs for both suspension and locating the axle housings (there are no radius arms with the leaf springs). The Dana 44HD TTB uses the same Dana 44 model TTB differential housing as the Dana 44 TTB.

The axle housings (beams) for the Dana 44HD TTB are made of .250 wall steel and they are shorter and heavier than the regular Dana 44 TTB. Because of the difference in length between the Dana 44 TTB and Dana 44HD TTB, the pivot brackets are designed differently, and attach to the front crossmember in different locations.

The Dana 44HD system uses larger steering knuckles, spindles, bearings, and hubs (8-lug) than the light duty version, and they cannot be interchanged. The only component interchangeable between the Dana 44 and Dana 44HD is the 3rd members (differential housing) and the locking hub mechanisms.

In 1987, the F-250 Dana 44HD TTB was replaced with a Dana 50 TTB.

Above is a comparison between the Dana 44HD TTB / Dana 50 TTB axle beam (top) and the normal Dana 44 TTB axle beam (bottom).

Dana 50 TTB (Heavy Duty):

There was also a Dana 50 TTB version, which was the heaviest version and used on the Ford F-250HD (over 8500# GVW) trucks and 1980-1985 F350s. The same axle housings are used for both the Dana 44HD and Dana 50 TTB, but the Dana 50 uses a 9-inch ring gear, and the Dana 44HD uses a 8.5-inch ring gear. The Dana 50 uses larger axle shafts, u-joints, and locking hubs than the Dana 44HD.

The Dana 50 TTB 3rd member (housing) will bolt to the Dana 44 beam, but you can’t swap any of the other parts to your Dana 44. The exception is the inner axle shaft and slip yoke on the passenger side. Click HERE for more information.

The Dana 50 TTB was used from 1987 to 1998.

For more information on the Dana 50 TTB, click HERE.

Hot To Tell The Difference Between Dana 44HD TTB And Dana 50 TTB:

The Dana 50 TTB hubs are massive, the same size as the hubs on a Dana 60. These are about 4-inches across where the cap meets the actual “hub”. There is also a “50” stamped below the pinion yolk. Here’s a pic of a Dana 50 TTB hub:

If the axle is not in the truck, or missing the hubs, you can look at the axle shafts from the back side of the axle, and check the u-joint size. The Dana 44 TTB and Dana 44HD TTB both use Spicer 760x (formerly 297x) u-joints which are 2.188 inches wide, and the Dana 50 TTB uses a Spicer 799x (1350) u-joint which is 3.622 inches wide (see image below)

Dana 44 TTB Locking Hubs:

Most people are familiar with the locking hubs on Dana 44 axles. The Dana 44 TTB uses the same locking hubs, except for some 1987-1988 models.

For some reason in 1987-1988, Ford used a one piece flange style manual locking hub similar to the ones found on the Ford Ranger.

Dana 44 TTB Axle Shafts:

• 1980-1996 Outers (stub shaft at spindle) are all the same unless it’s a 1987-1988 with flange style hubs (9.81 inches)
• 1977-1988 Outers (stub shaft at spindle) is not the same as the above listed 1980-1996 shafts
• 1980-1996 Driver side inner shafts are all the same (15.77 inches)
• 1980-1982 Passenger side axle shafts (intermediate) are different to accommodate bolt on inner shaft
• 1983-1996 Passenger side axle shafts (intermediate) are all the same (24.77 inches)
• 1980-1983 slip yokes are 5.50 inches long
• 1984-1996 slip yokes are 5.062 inches long

Dana 44HD TTB & Dana 50 TTB Axle Shafts:

• 1980-1987 Dana 44HD Passenger side axle shafts (intermediate) are 23.65 inches
• 1980-1987 Dana 44HD Driver side axle shafts are 17.19 inches
• 1985-1988 Dana 50 TTB Passenger side axle shaft (intermediate) 23.94 inches
• 1985-1988 Dana 50 TTB Driver side axle shaft 17.11 inches

Dana 44 TTB Third Member Housings:

Here’s a setup you don’t see that often. It seems that the 1980-1983 Dana 44 TTB and Dana 50 TTB trucks that were equipped with a front limited slip differential also came with a unique housing that held the passenger side axle shaft in externally with (3) bolts. In the photo below, you can see the typical housing on the left that the passenger side axle shaft slides in to, and then the shaft is retained internally with a c-clip. You’ll notice that the housing on the right has a much larger opening to allow for a bearing, and the whole assembly is retained by (3) bolts.

The photo below shows the difference between the passenger side axle shaft that is held in with a c-clip, and the one that is bolted in.

Why would you want this setup? Because you don’t have to worry about a broken c-clip, and the shaft sliding out of the housing when the suspension flexes off-road. Some people put a spring in the passenger side slip yoke to keep pressure on the shaft so it stays in place. This is permanent fix to that problem if you can find the housing with the bolt in shaft still in place.

This is what you would likely see if you were to crawl under one of these trucks and look:

Here’s the Spicer part numbers for the bolt in parts if anyone is interested:

• Seal 35938
• Bearing Assembly 566075
• Retaining ring 36121
• Seal for the other side of the diff is 40710

Parts for the C-clip version are:

• Bearing 566121
• Seal 40773

Ring Gear Gear Carriers:

Dana 44s are reverse rotation hi-pinion. Most are a 3.50 gear from the factory. A new carrier is needed for gears lower (numerically higher) than 3.92

There are (3) styles of carriers:

• Type 1: 1980-1982 gear carriers used a bolt on axle retainer, used different bearings and seals than 1982-1996 (Types 2 & 3)
• Type 2: 1982-1992 gear carriers used a c-clip to retain the axle, used different bearings and seals than 1980-1982 or 1993-1996 (Types 1 & 3)
• Type 3: 1993-1996 gear carriers used a c-clip to retain the axle, used different bearings and seals than 1980-1992 (Types 1 & 2)

Dana 44 Spindles:

Not all Dana 44 TTB spindles are the same.

• 1980-1992 – These spindles are basically the same, but the keyway slot is cut past the threads on one of them. These spindles have a 6-bolt pattern.
• 1987-1988 – These spindles ares completely different and shorter to work with the flange style locking hubs
• 1993-1996 – These spindles use a different size inner bearing, and the ABS versions of these spindles have holes cut in to the flange for the sensors. These spindles have a 5-bolt pattern

If for some reason you need to replace a spindle, you need to be sure that your ordering one that matches the one your replacing.

See the photo below for reference.

1980-1992 Dana 44 TTB Spindle:

DANA SPICER 707178X

Replaces old number Dana Spicer 41928

Fits Ford F150 with Dana 44 IFS front axle (1980-1992)

Dimensions:

• Keyway Slot = .312 in. wide (5/16 inch)
• Bore ID = 1.300 inches
• A = 1.622 in. OD for Outer Wheel Bearing
• B = 1.778 in. OD for Inner Wheel Bearing
• C = 2-1/2 in. OD for Seal
• D = 3-3/8 in.
• E = 1/2 in.
• F = 3/8 in.
• G = 5-7/16 in.
• H = 6-1/4 in.
• K = 4-3/4 in.
• Bolt Holes = 6
• Bolt Hole Diameter = .400 in.

1987-1988 Dana 44 TTB Spindle (Flange Style Locking Hubs):

DANA SPICER 42348

1993-1996 Dana 44 TTB Spindle (non-ABS):

1993-1996 Dana 44 TTB Spindle (With ABS):

DANA SPICER 75304X

1980-1988 Dana 44HD TTB Spindle:

DANA SPICER 707043X

Replaces old number Dana Spicer 41929

Fits Ford F250 with Dana 44HD IFS front axle (1980-1988)

Dimensions:

• Keyway Slot = .312 in. wide (5/16 inch)
• Bore ID = 1.300 inches
• A = 1.622 in. OD for Outer Wheel Bearing
• B = 2 in. OD for Inner Wheel Bearing
• C = 2-1/2 in. OD for Seal
• D = 3-3/8 in.
• E = 1/2 in.
• F = 3/8 in.
• G = 5-1/8 in.
• H = 6 in.
• K = 4-3/4 in.
• Bolt Holes = 8
• Bolt Hole Diameter = .400 in.

Dana 44 TTB Steering Knuckles:

• 1980-1985 Knuckles have bolt on calipers and 6 bolts holding the spindle to knuckle. (strongest?)
• 1993 Knuckles have tension pin style calipers and 5 bolts holding the spindle to knuckle
• 1987-1992 Knuckles have tension pin style calipers and 6 bolts holding the spindle to knuckle
• 1994-1996 Knuckles have two bolt style calipers and 6 bolts holding the spindle to knuckle. Also have ABS provision.

The photo below shows the difference between the typical Dana 44 TTB steering knuckle on the left, and the Dana 44HD TTB / Dana 50 TTB steering knuckle on the right. While it hay be difficult to see, the balljoint spacing is about a 1/2-inch wider on the Dana 44HD knuckle.

Dana 44 TTB Brake Rotors:

The Dana 44 TTB used (3) different style of brake rotors from 1980-1996.

1980-1986 & 1988-1993:

Specifications:

• Brake Rotor Casting Type Vented
• Brake Rotor Diameter, Outer 11.720 in
• Brake Rotor Thickness, Discard 1.120 in
• Brake Rotor Thickness, Nominal 1.185 in
• Coating Bare
• Height, Overall 2.704 in
• Performance Level Standard Performance
• Packaged Weight 12.200 lb
• Wheel Bolt Circle Diameter 5.500 in
• Wheel Bolt Holes, Primary 5 Each

1987.5 – 1988 With Flange Style Locking Hubs:

Specifications:

• Brake Rotor Diameter, Outer: 11.720 in
• Brake Rotor Thickness, Discard: 1.122 in
• Brake Rotor Thickness, Nominal: 1.185 in
• Height, Overall: 2.975 in
• Surface Finish: Plain
• Wheel Bolt Circle Diameter: 5.500 in

1994-1996:

Specifications:

• Vented or Solid Style Rotor: Vented
• Diameter:11.72″
• Height: 2.54″
• Number Bolts/Holes: 5
• Bolt Circle Diameter: 5.5″
• Center Hole Diameter: 3.88″
• Nominal Thickness: 1.025″
• Discard Thickness: .960″

Dana 44 Specifications:

Dana 44 TTB Labeled:

Dana 44 TTB Diagram:

Dana 44 TTB Exploded View – Click The Image To Enlarge

Dana 44HD TTB Diagram:

Dana 44HD TTB Exploded View – Click The Image To Enlarge

Dana 44 TTB And Off-Road:

While most people that like to climb rocks end up replacing these axles with a traditional tube style Dana 44 or Dana 60 solid axle, the guys that like to go fast off-road and want a lot of wheel travel love these axles.

(Don’t try this with your stock suspension)

This however relies on suspension modifications, as well as bracing and support added to the stock axle beams. These suspension systems are far superior to the bolt on suspension kits you get from the large aftermarket suspension manufacturers. These ‘long travel’ kits typically use modified and braced replacement axle beams, longer radius arms, new shock towers, and coil overs.

Links:

1978-1998 Dana Axles Parts Manual (Dana 44 TTB Starts on Page 121)

Dana 44 TTB Maintenance Manual

Resource: BroncoCorral.com