If you’re new to towing or looking to know more about repairing a car’s system, you may have come across the term “torque tube“. But, what is a torque tube?
In this article, I will give you the correct answer with an explanation of the construction and application of this gadget.
What Is A Torque Tube?
Torque tube systems are a kind of power transmission plus braking equipment that use a fixed casing around the drive shaft.
These systems are most common in vehicles with a front engine and a rear-drive configuration.
Construction
The “torque” in question is not the torque applied by the driveshaft perpendicular to the vehicle’s centerline; rather, it is the torque provided by the rear wheels.
The torque tube is a solution to the engineering challenge of transmitting the traction forces produced by the drive wheels to the vehicle’s chassis.
The “torque tube” transfers this force by directly linking the axle differential to the gearbox, which in turn pushes on the engine/transmission and, through the combustion engine mounts, onto the car frame, propelling the vehicle forward.
Conversely, the Hotchkiss drive relies on other suspension elements like leaf springs and trailing arms to transfer traction forces to the vehicle’s chassis.
Torque tube design has a ball-and-socket connection at one end termed a “torque ball” so that the axle and gearbox may move relative to one another as the suspension travels.
A panhard rod is frequently used to confine the axle in the lateral (side-to-side) direction since the torque tube cannot do so.
In the back, the combined effect of the panhard rod and the torque tube makes it simple to install soft coil springs, improving ride quality.
Besides transferring traction forces, the torque tube is hollow and houses the rotating driveshaft, which is always in motion.
The universal driveshaft joint, which allows for mutual rotation between the two ends of the driveshaft, is housed within the hollow torque ball.
Driveshafts typically have a single ubiquitous joint, which has the drawback of causing engine speed fluctuations in the driveshaft if the shaft is not vertical.
Instead, Hotchkiss drives employ two universal joints, which balance out engine speed fluctuations and maintain the constant speed even when the propeller shaft is curved.
Application
American Ford automobiles up to 1948 employed the torque tube, which was characterized by using transverse springs that were too weak to withstand the thrust.
The 1930s Buick and the 1941 Nash ‘600’ model, which both used coil springs, required the installation of a torque tube.
Through the 1966 model year, American Motors (AMC) built its big automobiles (Rambler Classic and Ambassador) using a coil spring rear suspension arrangement with a torque tube.
The “torque tube” of the 1961–1963 Pontiac Tempest was bent uniquely, dropping down four inches (approximately 10 centimeters) to accommodate the automotive vehicle’s solid steel driveshaft (dubbed the “rope shaft”), which had universal joints at either end.
The primary goal was to reduce the car’s floor height and increase the cabin’s usable space. Torque tube designs were also utilized in the Peugeot 504, Peugeot 505, and Volvo 300 Series (save for estate/station wagon body styles).
Both Sprint and Midget cars employ variations of the torque tube driveline. In addition, many high-performance vehicles, including the Porsche 924, Porsche 928, Porsche 944, the C5 and C6 Chevrolet Corvette, Lexus LF-A, Aston Martin DB7, Aston Martin DBS, Aston Martin DBR9, Maserati Quattroporte V, Maserati GranTurismo, and Mercedes-Benz SLS AMG, employ variants of this design—typically with rear-mounted transaxles.
The Tatra vehicle, manufactured in the Czech Republic, is unique among full-size trucks in that each rear wheel is suspended by a torque tube.
How to Install Torque Tube
You already have the answer to the question, “What is a torque tube?“. So let’s continue with the process of installing a torque tube.
Step 1
Verify that the valve actuator is in its original position. Both the valve and the actuator need to be in the state open for plug valves. For butterfly or ball valves, make sure the valve and actuator are both in the open position.
For valves 24 inches or less in diameter, the disc must close equally on both sides by no more than 1/8 inch. For example, butterfly valves having a diameter of thirty inches or more need a uniform 1/4-inch closure on both sides. Setting travel stops later in Step 9 will also need measured validation of the disc’s evenness.
Step 2
Take off the floor stand assembly’s actuator’s indication arrow and gear cover. Take the key out of the lock and put it somewhere safe.
Step 3
Check that the packing retention plate for the butterfly valve remains in place.
Step 4
Inspect the torque tube’s female (lower) connection for a key that has been securely attached. A key should be inserted into the valve shaft if one is not already attached to the bottom torque tube connection.
Step 5
Drop the torque tube onto the shaft or valve stem and fasten it with a strap. The torque tube will sit atop the stem or shaft of a valve with automatically fastened packing, like a plug or ball valve. The torque tube for butterfly valves will sit on top of the packing retention plate.
Step 6
Turn the torque tube upside down and lower the floor stand onto it. Check that the torque tube is vertical using a level, then secure it.
Make sure the torque tube is not bound in any way by shimming the floor stand’s base until it is perfectly centered. Use bolts measuring 5/8 inches to anchor the floor stand to the ground.
Step 7
To prevent the torque tube from coming loose from the actuator, reinsert the key from Step 2. Next, mount the directional arrow indication.
Step 8
The stop bolts on the torque tube plate should be backed out as much as feasible without removing them to open the ball and butterfly valves.
Step 9
To ensure the valve is entirely closed, it must be cycled through its full range of motion using the actuator. As mentioned in Step 1, guarantee that the disc is leveled on butterfly valves. In this case, the actuator’s closed-off stop bolt may need to be moved to allow for more motion.
Step 10
As soon as the valve is in its closed status, the stop bolts should be tightened to the torque values shown in the table.
Step 11
Reverse the previous steps by moving the valve from its closed state to its open state and back to its closed state again. Make that the stop bolt can be tightened with no valve binding and that it returns to a completely closed position when loosened.
You also can check this video to follow the mentioned steps with more detailed guides.
FAQs
What Is The Difference Between A Torque Tube And A Drive Shaft?
The torque tube connects the back of the gearbox to the vehicle’s axles at the back.
The torque tube replaces the traditional drive shaft and its U-joints with a spherical bearing arrangement located at the back of the gearbox.
As a result, the torque tube connects the various parts of the driveline and serves as a rear-end location member.
What Is A Torque Tube In A Gas Turbine?
The engine’s power created in the turbine section is sent to the compressor section through the torque tube.
The transmitted power through the torque tube spins the compressor, drawing in and compressing additional air to keep the turbine running smoothly.
What Cars Use A Torque Tube?
The most popular cars with torque tubes are the Porsche 944, 924, and 928. The Nissan GTR utilizes one, while the C6 and C5 Corvettes utilize a torque tube.
Conclusion
What is a torque tube? Vehicles with a front engine and a rear drivetrain often employ a torque tube system, a power transmission, and a braking technique that includes a fixed enclosure around the drive shaft.
The main advantage of torque tubes is keeping the vehicle’s rear end in place during rapid acceleration and deceleration. Therefore, you have to check it regularly to ensure your safety.