A driveshaft or driving shaft is a device that transfers power from the engine to the point where work is applied. In the case of automobiles, the drive shaft transfers engine torque to the drive axle, which connects the two wheels together on opposite sides and with which they turn. The driveshaft is also sometimes called propeller shaft.
Drive shafts are essentially carriers of torque. Before they became a vogue, older automobiles used chain drive and even generators to transmit power to the wheels. Drive shafts today, however, have U-joints, devices which help them to move and down during suspension. Some drive shafts also have another kind of joint, called slip joints, which allow them to adjust their lengths to the movement of the suspension.
Adjustments aside, drive shafts are of different lengths depending on their use. Long shafts are used in front-engined, rear-drive vehicles while shorter ones are used when power must be sent from a central differential, transmission, or transaxle.
Because of the load they carry, driveshafts must be strong enough to bear the stress that is required in the transmission of power. Thus, they must be periodically checked, too. Some U-joints do not require periodic lubrication as they have been designed that way by their manufacturers, but they must be inspected at each oil check nevertheless. Bad U-joints could cause the driveshaft to separate from the vehicle.
Drive Shaft Buyer's Guide
A drive shaft is a metal rod with splined components connecting the transmission and the differential. It serves as the spine on your car which transmits torque to the axles.
- Types of drive shaft include single-piece (flanged) drive shafts and two-piece and three-piece drive shafts.
- Sign that you may be having a failing drive shaft include difficulty in turning the wheel, vibration, audible squeaking noise and vehicle shake during acceleration.
- Price for an individual part usually ranges from $150 to $1400.
- Drive shafts are important to maintain optimum drivability of the car and to avoid breaking the transmission. Drive shafts are also essential for a comfortable and worry-free drive.
Have you ever wondered how the wheels on a rear-wheel or all-wheel drive car spin despite being far from the engine and transmission? Simple; there’s a long rod that connects the transmission to the rear differential. This rod is known as the drive shaft or propeller shaft, which incorporates splined slip joint and sliding yoke that transmits torque to the rear wheels. Basically, the engine’s pistons deliver power to a set of gears inside the transmission. The gears then turn the splined slip joint, which turns the pinion inside the rear differential, causing the axles to rotate.
Where is the drive shaft?
The drive shaft, like the transmission assembly, is hidden from plain sight but can be located underneath the hump in the rear passenger floor. It serves as the spine of your car, and similar to spine’s function which is to transmit neurons from the brain, propeller shaft delivers the torque from the transmission to the rear axle of your car. It runs along the center of your car from the transmission hump all the way to the pinion of the rear differential. Be informed that front-wheel drive cars don’t feature drive shafts. Instead, they feature a transaxle, which is a combination of the transmission and front differential.
Types of drive shaft
Drive shafts vary from one vehicle to the other due to factors like vehicle length, drivetrain layout, and transmission design. Considering these factors, there are two main types of drive shaft; the single-piece and multiple-piece drive shafts.
Single-piece (flanged) drive shafts are used in small vehicles of which the distance between the engine and axles are short. They are also utilized in mid-engine, rear-wheel drive (MR) and four-wheel-drive (4WD) vehicles.
Two-piece or three-piece drive shafts, on the other hand, are used in long vehicles of which the engine and axles are far from one another. This type of propeller shaft is also used in front engine, front-wheel drive (FF) and 4WD vehicles. The divisions of the shaft assembly allow it to absorb vibrations and bending due to extreme rear axle and suspension movements.
Signs that you may be having a failing drive shaft
Remember that the drive shaft plays an important role in driving the wheels from a stationary position. It also contributes to your car’s overall driving comfort because a faulty propeller shaft can result to minor and major issues on the road. The symptoms vary from audible sounds to perceivable inconsistencies, all of which are not to be ignored. If you experience these signs while driving, consult your mechanic as soon as possible.
Difficulty in turning the wheel
A bent or damaged drive shaft can restrict your wheels from turning properly, which then results to difficulty in maneuvering the car on curves. This sign should be easy to tell due to the increased resistance from the tire when steering the car. Wheels that won’t properly turn cause inconveniences both during slow and high-speed drives.
Vibrations while driving is a vague symptom because it could be anything from your engine to wheel alignment. Be more concerned when the vibration persists even when your car is stationary. Vibration during idle or drive could be due to a badly-shaped drive shaft, literally. Drive shafts, especially the one-piece type, can bend as a result of extreme suspension and axle movements. The bending will make the rotation of internal parts difficult, causing the vibration even when your car’s at rest.
Audible squeaking noise
Part of the signs of a damaged shaft is unusual noises, even more so that it has rotating and moving parts. Squeaks during accelerations that tames down at higher speeds is a sign of the drive shaft’s badly damaged or dry coupling connection known as the U-joint. This squeaking noise can also be heard in a form of clunking, rattling, and scraping. . If this happens to you, don’t risk ignoring it; drive to your mechanic right away, as it could lead to more serious problem in your drivetrain.
Vehicle shake during acceleration
Aside from unusual noises, shaking during acceleration could be a sign of a loose U-joint. . A malfunctioning U-joint, as well as a worn-out center bearing, are what’s causing the jerkiness whenever you try to step on the pedal from rest or low speed. Although it might feel like a natural vehicle behavior, addressing it sooner can save you from possible major problems that could end up reaching your transmission or engine.
How much is an OE replacement drive shaft?
Drive shafts are sold as an individual piece, assembly, or in sets. Individual OE replacement drive shafts are priced around $150 to $1,400 but if you need an assembly, you’re looking at roughly $270 to $1,700. A set of front and rear shafts, on the other hand, are priced somewhere along the $500 to $600 mark. Prices could even go higher depending on the make, quality, and the vehicle of which the product is fitted on.
Why do you need to replace a faulty drive shaft?
There is a simple explanation on why you need to replace a faulty drive shaft, as well as other parts in your vehicle that you may find failing. Basically, damaged or worn-out parts like the drive shaft affect your vehicle’s drivability, which could eventually result to minor to major inconveniences on the road. The thing is, most drivers tend to just shrug a shoulder and risk it until it’s too late. However, you have to take note that the drive shaft is directly connected to your transmission and everyone knows that a car’s transmission assembly is a little expensive to deal with. So, the moment you start experiencing a problem that you think is caused by the drive shaft, make it a priority to bring your car to the service center.
Important Facts You Need to Know About Driveshaft
Help your car achieve the maximum turning capacity of its wheels by replacing its old and creaky driveshaft. Get a new one today and see instant results.
Have you ever thought about how the power from your engine reaches your car's wheels? It's actually very simple and there's no black magic involved. You don't even need to have a degree in rocket science to understand how this is done. This process is made possible through the driveshaft.
Driveshafts are elongated rotating shafts or poles that connect the transmission output shaft to the differential. Through this connection, the power from your engine can be transmitted to the wheels. Once the power has been transmitted, the wheels will start to turn and then of course, your car starts to run.
For the driveshaft to accomplish this function, it has to be made from a sturdy material. And one such material is aluminum. An aluminum driveshaft is perfect because it is not only tough but also light-weight.. Plus, an aluminum driveshaft will also improve your car's balance and decrease your car of unnecessary weight. This will improve your car's overall performance since it has a driveshaft that works the same but is lighter. So, if you're planning to get a new driveshaft, go for the aluminum ones. And why not? You get several advantages on top of its basic function. You can consider it as giving your driveshaft a good upgrade.
Driveshaft: Just the Facts
Balance over power. It's a helpful piece of advice anyone holding a steering wheel should remember. It doesn't apply only to driving but to car parts as well, especially the driveshaft. It's that long cylindrical piece of metal hanging under your car, rotating every time you step on the throttle while in gear. Your vehicle is usually equipped with two drive shafts that transfer torque and power to the wheels. Despite the driveshaft's metal structure, though, wear and tear can still weaken it to the point where it deforms. This is especially true if you like going for drives on the off-road trails. Once the driveshaft loses its balance, it can rattle itself loose from your vehicle's transmission and damage other auto parts nearby. So once damaged and loose, it endangers the rear differential, hoses, and brake and fuel lines. Don't let things get out of hand. If this auto part becomes too worn-out for use, then it's time for a replacement. CarParts.com has just the right one for you.
• Designed and balanced using latest computer-aided technologies
• Made from lightweight yet sturdy material that ensures durability and performance
• Lasts longer than stock counterparts
Driveshaft Buying Guide
A driveshaft is described as a pole that transfers power from the engine to the drive wheels. It is important that your car is equipped with a driveshaft fit for your car. A bad one could be costly because of lost power.
Have in mind some considerations when picking a new driveshaft for your car or truck.
Power and Load Balance
A driveshaft's transferring capabilities should be balanced with an engine's power. Remember that with every horsepower increase, there also is the increase in load the driveshaft must carry. Too much power from a powerful engine can twist and destroy the driveshaft. On the other hand, make it too strong for a weak engine and you'll be spending too much on something you and your car does not need.
Length and Diameter
Dimensions of a driveshaft have great effects on its critical speed. Basically, critical speed is the limit a driveshaft has of properly being able to carry an engine's power. Exceed the critical speed and the driveshaft becomes shaky and unstable. Push it more and you'll get it bent and useless. A general rule is that a long and wide driveshaft has a higher critical speed compared to short and thin ones.
A driveshaft is constructed using different materials which also affect its critical speed. Take note of this when picking one for your driving or racing needs.
- OEM: The lowest level of driveshaft capable of handling engines between 350-400HP. This type is not suitable for racing.
- DOM/Chrome-Moly: This steel driveshaft can carry the power range of 1,000-1,300HP. It is quite heavy compared to other types. Chrome-molly driveshafts are tougher variant and can carry the same load as the DOM type.
- Aluminum: Though lightweight, this is common in performance cars because of its capacity to support 900 to 1,000 HP. It can be prone to twisting because it is lighter than steel.
- Carbon Fiber: This is the strongest and most expensive type of driveshaft. With high a high critical speed, carbon fiber can carry an engine with 900 to 1,500 HP.
Fixing a Busted Driveshaft
A driveshaft is responsible for transferring power from the transmission to the axles of the drive wheels. If it is damaged, a lot of power is wasted and lost. Hence, it is important to immediately repair broken a broken driveshaft to ensure the car runs well.
Difficulty Level: Moderate
- Floor jack and jack stands
- Wrench set
- Socket set
- Handheld sledgehammer
- Transmission Fluid
- Replacement driveshaft
Step 1: Park your car on a flat surface, put it in neutral gear, and elevate with a floor jack. Secure the car on jack stands to avoid accidentally dropping the car.
Step 2: Go underneath the car and locate the rear yoke of the driveshaft which is connected to the rear axle. Mark the connection of the driveshaft to the axle with chalk for later reference. Wedge a screwdriver in the u-joint gap and remove one of the bolts. To access the other bolts, take off the screwdriver and manually turn the driveshaft. Once other bolts are in reach, wedge the screwdriver again and remove the bolt. Once the last bolt is removed, support and lower the driveshaft and lower it to avoid a sudden drop. In case the driveshaft is stuck, lightly tap it with a small sledgehammer.
Step 3: Repeat step 2 for the front yoke.
Step 4: Once the driveshaft is completely off, prepare the new driveshaft by rubbing transmission fluid on the front yoke to be attached to the transmission. Make sure the splines and joints fit when the front yoke of the driveshaft is inserted. Use your chalk markings as a guide. Secure all bolts removed.
Step 5: For the rear yoke, simply raise it to your chalk marking, fit it to the joint and return all the bolts removed.
Step 6: Lower the car and start the engine. Warm up the car for a few minutes before taking it on a test drive.
The whole process can be done in a little over 1 hour
- Ask for help from another person especially when fitting the joints and spines.
- Use goggles to prevent accidental drippings to the eyes.