When it comes to trucks and utility vehicles, something has to make up for all the height differences between the rear axles and the transmission. The vehicle must find a way of channelling all that power from the transmission to the axles at the far end of the truck. Manufacturers rely on universal joints (U-joints) to achieve this. A U-joint bends in line with the movement of the driveshaft to compensate for any misalignment while still delivering power where it is required. Here is some information that will help you diagnose a bad universal joint when using your truck:
Vibrations
Vibrations are a red flag for anyone with a truck. The vibrations associated with bad U-joints will affect the way the whole vehicle travels while moving at speed. Normally, you will feel the vibrations rip through the whole body of the truck. They occur at a high frequency compared with other kinds of vibrations caused by loose wheels or other misfiring components.
When you feel vibrations ripping through the truck, it means that the U-joint is worn out to a point where it allows the driveshaft to shift from its normal position. This leads to an imbalance as the driveshaft oscillates faster than the truck's wheels.
Dislocated Driveshaft
A dislocated driveshaft is a sign of a failed U-joint. It happens in the final stages of mechanical failure after the trucker was unable to address the problem in the initial stages. Excessive wear on the U-joint will compel it to break and let go of the driveshaft, detaching it from the rear axle and the transmission. You shouldn't let your truck get to this point because repairs will involve more than a small fix to the U-joint. If things get this far, you must replace the whole driveshaft.
Unusual Noise When the Vehicle Starts Moving
A new U-joint comes with greased bearings to make movements fast, smooth and quiet. The bearings shift slightly as the U-joint rotates, generating heat that can melt the grease. The movements also throw some of the grease out of its compartments and leave the bearings dry. Sadly, some manufacturers do not put grease fittings on the bearing components, making it impossible to add any lubricants. The original grease wears off and ends the useful life of the whole U-joint. You can detect the failure of such U-joints when you hear unusual squeaking noise from underneath the truck. The sound pops up as soon as your vehicle starts moving forward or backward.
Contact a truck servicing repair company today to learn more about how to address these issues.
