Driveshaft Manufacturing
Our driveshaft manufacturing process can adjust as needed to the phase of production and industry requirements of our customers. The driveshaft is often oversimplified during the prototype phase of any new chassis or industrial design. There are variables in any new build that can create or modify several forces impacting driveshaft suitability. This can cause a reduction in bearing life and failure not only for the shaft itself but also the components to which it’s connected. We will assist your engineering team through the selection of series, angle calculations, and critical speed constraints.
Below are a series of calculations and tools to assist your engineering team in the setup of your driveshaft system. Please ensure your data is correct and you properly test fitment during the prototype phase as we cannot assume responsibility for application or data errors.
Feel free to contact us and upload any prints or specs for you application, we would love to partner with you on your next build.
Technical Requirements
Several calculations are required to verify the appropriate driveshaft(s) for your specific chassis application. Most of these center around torque and RPM of the driveshaft itself. Below is an explanation of the torque calculation requirements:
Driveshaft Torque Requirements vs Series Selection
Driveshaft series selection is crucial to any system and weighs torque and bearing life requirements vs loss of output.
Maximum Torque in Low Gear
The main calculation for selecting a driveshaft in a chassis is used to determine the maximum amount of torque that is applied to the front of the driveshaft. It starts with the gross engine torque and applies all gear ratios that amplify / reduce this force. It is then reduced by the efficiency of each component that is applicable to the front of the system.
Where:
*Low gear ratio is always a forward gear ratio and is normally 1st gear. Some transmissions will provide a significantly higher numerical 1st gear ratio (i.e. > 18.0). Please contact us or refer to Dana’s & Cummins – Meritor's guide for the qualifications for using 2nd gear for this calculation.
**These efficiencies are referenced in Dana’s driveshaft application guidelines. We have also provided Cummins – Meritor, which differs for these numbers, as well as max driveshaft torque threshold.
Wheel Slip Torque
The wheel slip torque calculation is used to determine the amount of torque required for the wheels on the vehicle to slip. This calculation is only to be considered for road applications where payload does not exceed gross combined weight. Off highway and specialty applications can have other factors that can reduce or remove wheel slip making the maximum torque in low gear calculation the proper threshold for your series selection.
Please reference Dana & Cummins – Meritor for application guidelines & calculations.
Driveshaft System Envelope & Length vs. Number of Driveshafts
Once torque requirements for the shaft are determined, the next step is to look at any clearance issues that can constrain the max swing and/or tubing diameter. It is important to provide adequate clearance for the movement of the system under load and within the arc of the suspension.
Below is a table listing series, max torque, swing diameter & min/max tubing diameter for heavy duty series.
10 Series
1 Swing diameter clears yoke by 0.06 in (1.5 mm)
2 Tube thickness diameter can modify the functional torque limit.
| Series | Functional Torque Limit | Swing Diameter1 | Tube Diameter2 | |||
|---|---|---|---|---|---|---|
| lb-ft | Nm | in | mm | min (in) | max (in) | |
| 1310 | 1,719 | 2,330 | 4.00 | 101.6 | 1.250 | 4.000 |
| 1330 | 1,991 | 2,700 | 4.56 | 115.8 | 2.000 | 5.000 |
| 1350 | 2,876 | 3,900 | 4.56 | 115.8 | 2.000 | 5.000 |
| 1410 | 3,467 | 4,700 | 4.94 | 125.5 | 2.500 | 5.000 |
| 1480 | 4,057 | 5,500 | 5.75 | 146.1 | 3.000 | 5.000 |
| 1550 | 5,163 | 7,000 | 6.00 | 152.4 | 3.500 | 4.000 |
| 1610 | 6,000 | 8,135 | 7.00 | 177.7 | 3.500 | 4.000 |
| 1710 | 11,358 | 15,400 | 7.89 | 200.2 | 3.500 | 4.500 |
| 1760 | 12,000 | 16,270 | 8.40 | 213.2 | 4.095 | 4.095 |
| 1810 | 16,500 | 22,370 | 9.10 | 231.0 | 4.590 | 4.590 |
C Series
1 Swing diameter clears yoke by 0.06 in (1.5 mm)
2 Tube thickness diameter can modify the functional torque limit.
| Series | Functional Torque Limit | Swing Diameter1 | Tube Diameter2 | |||
|---|---|---|---|---|---|---|
| lb-ft | Nm | in | mm | min (in) | max (in) | |
| 5C | 4,130 | 5,600 | 4.85 | 123.0 | 2.500 | 3.543 |
| 6C | 5,310 | 7,200 | 5.91 | 150.0 | 2.750 | 3.543 |
| 7C | 7,892 | 10,700 | 6.23 | 158.0 | 3.000 | 4.000 |
| 8C | 11,432 | 15,500 | 8.51 | 216.0 | 3.500 | 4.000 |
| 8.5C | 14,973 | 20,300 | 6.90 | 175.0 | 3.543 | 4.724 |
| 9C | 20,209 | 27,400 | 8.79 | 223.0 | 4.528 | 4.724 |
| 10C | 29,281 | 39,700 | 8.87 | 225.0 | 5.000 | 5.000 |
| 11C | 30,683 | 41,600 | 9.26 | 235.0 | 5.669 | 5.669 |
| 12C | 45,876 | 62,200 | 11.86 | 301.0 | 6.299 | 6.299 |
| 12.5C | 46,466 | 63,000 | 11.62 | 295.0 | 6.299 | 6.299 |
| 14C | 88,950 | 120,600 | 14.18 | 360.0 | 8.622 | 8.622 |
| 14.5C | 79,657 | 108,000 | 12.84 | 326.0 | 8.622 | 8.622 |
| 15C | 55,612 | 75,400 | 10.76 | 273.0 | 6.500 | 6.500 |
SPL Series
1 Swing diameter clears yoke by 0.06 in (1.5 mm)
2 Tube thickness diameter can modify the functional torque limit.
| Series | Functional Torque Limit | Swing Diameter1 | Tube Diameter2 | |||
|---|---|---|---|---|---|---|
| lb-ft | Nm | in | mm | min (in) | max (in) | |
| SPL55 | 4,057 | 5,500 | 5.32 | 134.9 | 3.000 | 4.000 |
| SPL70 | 5,163 | 7,000 | 6.00 | 152.4 | 3.500 | 4.000 |
| SPL100 | 7,376 | 10,000 | 6.07 | 154.0 | 4.000 | 4.000 |
| SPL140 | 10,326 | 14,000 | 6.30 | 160.0 | 4.331 | 4.560 |
| SPL170 | 12,539 | 17,000 | 7.60 | 193.0 | 4.500 | 4.961 |
| SPL250 | 16,595 | 22,500 | 7.60 | 193.0 | 4.670 | 5.197 |
| SPL350 | 22,127 | 30,000 | 8.12 | 206.0 | 5.590 | 5.590 |
RPL Series
1 Swing diameter clears yoke by 0.06 in (1.5 mm)
2 Tube thickness diameter can modify the functional torque limit.
| Series | Functional Torque Limit | Swing Diameter1 | Tube Diameter2 | |||
|---|---|---|---|---|---|---|
| lb-ft | Nm | in | mm | min (in) | max (in) | |
| RPL10 | 6,000 | 8,135 | 7.01 | 177.8 | 4.000 | 4.000 |
| RPL14 | 10,000 | 13,558 | 7.81 | 198.1 | 4.095 | 4.095 |
| RPL20 | 12,000 | 16,270 | 7.81 | 198.1 | 4.000 | 4.095 |
| RPL25 | 17,200 | 23,320 | 9.11 | 231.1 | 4.590 | 4.590 |
| RPL25SD | 18,500 | 25,082 | 9.11 | 231.1 | 4.690 | 4.690 |
| RPL35 | 21,600 | 29,286 | 8.10 | 205.7 | 4.690 | 5.204 |
| RPL35SD | 25,815 | 35,000 | 8.10 | 205.7 | 5.204 | 5.204 |
Critical Speed RPM Calculation
Critical Speed – The RPM of the driveshaft reaches its natural frequency. Calculation of Critical Speed is the modulus of the material of the driveshaft along with tube diameter vs. the length of the driveshaft. (i.e. the longer the driveshaft, the lower the critical speed)
Adjusted Critical Speed – Corrects the critical speed to the maximum safe operating speed for safety and movement in the shaft.
Reference the Dana's Driveshaft Safe Operating RPM Calculator to verify the maximum driveshaft length suitable for your application. This will provide the information required to determine the number of driveshafts needed.
Driveshaft Angle Calculations
The universal joints in the driveshaft(s) are designed to rotate the shaft at an angle in reference to the components to which it is connected. The optimal angle of operation for a driveshaft coupling is 1.0˚-3.0˚ with a minimum 0.5˚ and a max of 5.0˚. If the coupling angle of the shaft exceeds 3.0˚, the life of the universal joint will be reduced. A diagram to calculate the coupling angle is shown below:
If the angle of each component is going in the same direction, the angle of each component is subtracted from one another. If the angles are in opposite directions, these angles are added together. This will provide the u-joint coupling angle. Below is an example of a driveline system with corresponding coupling angles.
If the examples above were referencing the same vehicle, the coupling angles for the side view and top view would need to be combined as shown below:
| $0_S$ | $0_T$ | $0_C$ | |
|---|---|---|---|
| ∠$C_1$ | 2.0 | 1.0 | 2.2 |
| ∠$C_2$ | 7.0 | 4.0 | 8.1 |
| ∠$C_3$ | 6.0 | 3.0 | 6.7 |
In the example above, $0_C$ references the combined coupling angles for the setup. ∠$C_2$ & ∠$C_3$ exceed the maximum allowable angles, this would significantly reduce bearing life and based on the application could cause excess vibration and/or system failure.
There are additional calculations and considerations in the Dana & Cummins – Meritor application guidelines.
DCJ, inc. only uses high quality components from trusted manufacturers. We source our production parts direct from leading driveshaft component manufacturers around the globe & trusted name brands that include but not limited to
