4x4 Truck Axle Tech - Axle 101
A Short Course In Choosing Or Building The Right Axle
By Jim Allen, Photography by Jim Allen
(In lb-ft, from published axle manufacturers' sources)
| Axle | COT | MOT |
| (lb-ft)* | (lb-ft)** |
| AAM/GM 7.25 IFS | - | 2,333 |
| AAM/GM 8.25 IFS | - | 3,581 |
| AAM/GM 9.25 IFS | - | 4,643 |
| AAM 9.25 Front | - | 4,663 |
| AAM/GM 7.63 SF Rear | - | 3,165 |
| AAM/GM 8.5/8.6 SF Rear | - | 3,829 |
| AAM/GM 9.5 SF Rear | - | 4,993 |
| AAM/GM 10.50 FF Rear | - | 6,242+ |
| AAM/GM 11.50 FF Rear | - | 8,321+ |
| Dana 28 TTB | 575 | 2,350 |
| Dana 30 Front (all) | 640 | 2,350 |
| Dana 35 TTB & IFS | 920 | 3,700 |
| Dana 44 Beam & TTB | 1,100 | 3,460 |
| Dana 50 Beam & TTB | 1,200 | 5,000 |
| Dana 60 Front | 1,500 | 5,550 |
| Dana 70 Front | 2,000 | 8,000 |
| Dana 35 Rear | 870 | 3,480 |
| Dana 44 Rear | 1,100 | 3,460 |
| Dana 60, 61-SF Rear | 1,500 | 5,500 |
| Dana 60, 61HD-FF Rear | 1,500 | 6,000 |
| Dana 70, 70U Rear | 2,000 | 8,000 |
| Dana 70 HD Rear | 2,000 | 8,800 |
| Dana 80 rear | 2,500 | 10,000 |
| Ford 8.8 IFS/IRS | 1,250 | 4,600 |
| Ford 7.5 Rear | 870 | 3,230 |
| Ford 8.8 (28spline) Rear | 1,250 | 4,600 |
| Ford 8.8 (31spline) Rear | 1,360 | 5,100 |
| Ford 9.75 SF Rear | 1,600 | 6,100 |
| Ford 10.25 FF Rear | 2,000 | 8,300 |
| Ford 10.50 FF Rear | 2,900 | 10,660 |
Notes
A "+" indicates that the manufacturer offers higher-rated versions.
*Continuous Output Torque
** Maximum Output Torque
(Ultimate strength [UTS] from destructive tests)
| Spicer # | UTS (lb-ft) | Spicer (lb-ft) |
| or Brand | | Yield |
| | Strength |
| 260X (D30) | 2,950 | NA |
| 297X (D44) | 4,600 | 1,600 |
| 760X (D44) | 5,400 | NA |
| 627X (D50) | 4,890 | 2,260 |
| 332X (D60) | 6,200 | 3,300 |
Note
Aftermarket super-strength U-joints like the CTM, the OX or the Yukon are at least two to three times stronger than OEM styles, but no exact test info is available as yet.
By Jim Allen
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