TTB vs. THE WORLD (AKA differences between Ford TTB axles)
Posted: Tue Sep 21, 2010 8:25 am
Ford made five different flavors of the TTB axle.
The Dana 28, 35, 44, 44HD, and 50.
Dana 28:
* 1983-1997 Ranger
* 1984-1990 Bronco II
* 1994-1997 Mazda B3000 + B4000
Ring Gear Diameter: 6.625
Ring Gear Bolts: (10) 3/8 x 24 RH
Cover Bolts: 12
Carrier Breaks: 3.45 / 3.73
Spline Count: 27
Pinion Support: False
Axle Lugs: 5x4.5
Center section is aluminum
Dana 35:
* Some 1990 Bronco IIs
* 1991-1994 Explorer
* 1990-1997 Ranger
* 1994-1997 Mazda B3000 + B4000
Dana 44:
1980-1996 1/2 Ton F150 & Bronco
Reverse rotation high pinion
Center section is steel
Ring Gear Diameter: 8.5"
Ring Gear Bolts: (10) 3/8" X 24RH
Cover Bolts: 10
Carrier Breaks: 3.73/3.92
Spline Count: 30
Pinion Support: False
Axle Lugs: 5x5.5
Dana 44HD:
The medium version was the Dana 44HD TTB used on F250 trucks under 8500# GVWR. This system uses leaf springs for both suspension and locating the axle housings (i.e., there are no radius arms w/ the leaf springs). The medium version uses the same Dana 44 model differential. The axle housings for the Dana 44HD TTB are made of .250 wall steel and they are shorter and heavier than the light duty system. The pivot brackets are designed differently and attach to the front cross member in different locations than a Dana 44 TTB or 2WD truck. The 44HD system uses bigger steering knuckles, spindles, bearings, and hubs (8-lug) than the Dana 44. They cannot be interchanged. The only component interchangeable between the 44 and 44HD are the hubs and diff pumpkin.
The same axle housings are used for both the Dana 44HD and Dana 50 TTB systems, so the only difference between them (out to the spindles) is the differential. There were actually two different versions of the Dana 50 TTB. The lighter Dana 50 TTB used the same components as the Dana 44HD TTB on F250HDs from 1980 to 1983 or so. The heavier version used somewhat bigger axle shafts, u-joints, spindles, bearings, hubs, and hub lockouts on F350s and later model F250HDs.
Reverse rotation high pinion
Center section is steel
Ring Gear Diameter: 8.5"
Ring Gear Bolts: (10) 3/8" X 24RH
Cover Bolts: 10
Carrier Breaks: 3.73/3.92
Spline Count: 30
Pinion Support: False
Axle Lugs: 8x6.5
Dana 50:
The Dana/Spicer Model 50 is an automotive axle manufactured by Dana Corp. and has been used solely in OEM Ford applications. Dana 50's were made as front axles only. The Dana 50 has a "50" cast in to the housing and is regarded to have more strength than a Dana 44, but not as much as a Dana 60. The Dana 50 was made as a solid axle and as a Twin Traction Beam (TTB) which pivots in the center allowing the wheels to move independently of each other. A unique quality of the Dana 50 axle is the lack of variation in both TTB and Solid axle versions, which simplifies repairs and upgrades. There were no carrier breaks and only one spline count. Gross axle weight ratings were lowered by Ford for safety and tire reasons. This TTB was used in the Ford F-250 from 1980 to 1997. The TTB Dana 50 was also used selectively in the F-350 from 1980 to 1986. The GVW was lower in a F-350 with a TTB Dana 50, than a F-350 with a solid axle. The gross axle weight rating of a TTB Dana 50 was 4600 lbs.
* Ring gear measures 9.0".
* 30 Spline Axle shafts.
* Gear Ratios: 3.55:1 - 5.38:1
* No carrier breaks
* Pinion shaft diameter: 1.375"
* Pinion shaft splines: 26
* Axle shaft diameter: 1.21"
* Axle spline diameter: 1.31"
* Axle Lugs: 8x6.5
* Center section is steel
Information for this thread has been sourced from Wikipedia, my own knowledge, and various other websites and forums.
The Dana 28, 35, 44, 44HD, and 50.
Dana 28:
* 1983-1997 Ranger
* 1984-1990 Bronco II
* 1994-1997 Mazda B3000 + B4000
Ring Gear Diameter: 6.625
Ring Gear Bolts: (10) 3/8 x 24 RH
Cover Bolts: 12
Carrier Breaks: 3.45 / 3.73
Spline Count: 27
Pinion Support: False
Axle Lugs: 5x4.5
Center section is aluminum
Dana 35:
* Some 1990 Bronco IIs
* 1991-1994 Explorer
* 1990-1997 Ranger
* 1994-1997 Mazda B3000 + B4000
Dana 44:
1980-1996 1/2 Ton F150 & Bronco
Reverse rotation high pinion
Center section is steel
Ring Gear Diameter: 8.5"
Ring Gear Bolts: (10) 3/8" X 24RH
Cover Bolts: 10
Carrier Breaks: 3.73/3.92
Spline Count: 30
Pinion Support: False
Axle Lugs: 5x5.5
Dana 44HD:
The medium version was the Dana 44HD TTB used on F250 trucks under 8500# GVWR. This system uses leaf springs for both suspension and locating the axle housings (i.e., there are no radius arms w/ the leaf springs). The medium version uses the same Dana 44 model differential. The axle housings for the Dana 44HD TTB are made of .250 wall steel and they are shorter and heavier than the light duty system. The pivot brackets are designed differently and attach to the front cross member in different locations than a Dana 44 TTB or 2WD truck. The 44HD system uses bigger steering knuckles, spindles, bearings, and hubs (8-lug) than the Dana 44. They cannot be interchanged. The only component interchangeable between the 44 and 44HD are the hubs and diff pumpkin.
The same axle housings are used for both the Dana 44HD and Dana 50 TTB systems, so the only difference between them (out to the spindles) is the differential. There were actually two different versions of the Dana 50 TTB. The lighter Dana 50 TTB used the same components as the Dana 44HD TTB on F250HDs from 1980 to 1983 or so. The heavier version used somewhat bigger axle shafts, u-joints, spindles, bearings, hubs, and hub lockouts on F350s and later model F250HDs.
Reverse rotation high pinion
Center section is steel
Ring Gear Diameter: 8.5"
Ring Gear Bolts: (10) 3/8" X 24RH
Cover Bolts: 10
Carrier Breaks: 3.73/3.92
Spline Count: 30
Pinion Support: False
Axle Lugs: 8x6.5
Dana 50:
The Dana/Spicer Model 50 is an automotive axle manufactured by Dana Corp. and has been used solely in OEM Ford applications. Dana 50's were made as front axles only. The Dana 50 has a "50" cast in to the housing and is regarded to have more strength than a Dana 44, but not as much as a Dana 60. The Dana 50 was made as a solid axle and as a Twin Traction Beam (TTB) which pivots in the center allowing the wheels to move independently of each other. A unique quality of the Dana 50 axle is the lack of variation in both TTB and Solid axle versions, which simplifies repairs and upgrades. There were no carrier breaks and only one spline count. Gross axle weight ratings were lowered by Ford for safety and tire reasons. This TTB was used in the Ford F-250 from 1980 to 1997. The TTB Dana 50 was also used selectively in the F-350 from 1980 to 1986. The GVW was lower in a F-350 with a TTB Dana 50, than a F-350 with a solid axle. The gross axle weight rating of a TTB Dana 50 was 4600 lbs.
* Ring gear measures 9.0".
* 30 Spline Axle shafts.
* Gear Ratios: 3.55:1 - 5.38:1
* No carrier breaks
* Pinion shaft diameter: 1.375"
* Pinion shaft splines: 26
* Axle shaft diameter: 1.21"
* Axle spline diameter: 1.31"
* Axle Lugs: 8x6.5
* Center section is steel
Information for this thread has been sourced from Wikipedia, my own knowledge, and various other websites and forums.