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GMC General Truck Torque Rods & U-Bolts
Frequently Asked Questions About GMC General Truck Torque Rods & U-Bolts
What are the key differences between OEM and aftermarket torque rods for GMC General trucks?
OEM torque rods typically feature rubber bushings that provide a smoother ride but may wear out faster under heavy loads. Aftermarket options often include polyurethane or solid bronze bushings that last longer and provide better stability, especially for heavy-duty applications. However, aftermarket rods with harder bushings may transmit more road vibration to the cab. Consider your primary use - OEM-style for comfort or upgraded bushings for durability and heavy hauling.
How do I determine the correct U-bolt size for my GMC General truck's specific year and axle configuration?
U-bolt sizing depends on three critical measurements: the diameter of your axle tube, the width of your spring pack, and the thread diameter. For GMC General trucks, most models from 1977-1987 use 3-inch round axle tubes requiring 3-1/8 inch inside diameter U-bolts. Measure your spring pack width at the center - standard packs are typically 2.5 to 3 inches wide. Thread sizes are commonly 5/8-inch or 3/4-inch. Always verify by measuring your existing U-bolts or checking your truck's build sheet for accuracy.
What tools and experience level are needed to replace torque rods and U-bolts on a GMC General?
Replacing torque rods requires basic hand tools including wrenches (typically 15/16" to 1-1/8"), a torque wrench, jack stands, and potentially a pickle fork for stubborn bushings. The job takes 2-4 hours per axle for someone with moderate mechanical experience. U-bolt replacement is more straightforward but requires proper torque specifications (typically 45-65 ft-lbs depending on size) and should be re-torqued after 500 miles. Both jobs require safely supporting the vehicle and axles - if you're uncomfortable working under a heavy truck, professional installation is recommended.
Are torque rods and U-bolts side-specific or interchangeable on GMC General trucks?
Most GMC General torque rods are not side-specific and can be installed on either the driver or passenger side. However, some models with offset differentials may have different length rods for each side - always compare your old parts or check part numbers. U-bolts are typically not side-specific but must match your spring pack configuration. Some GMC Generals have different spring pack thicknesses front to rear, requiring different U-bolt lengths. Always replace U-bolts in axle sets to maintain even clamping force.
What are the warning signs that my GMC General's torque rods or U-bolts need replacement?
For torque rods, watch for excessive axle movement during acceleration or braking, clunking noises from the rear suspension, uneven tire wear, or visible cracks in the rod bushings. Worn torque rods often cause the rear axle to shift backward under load. For U-bolts, look for loose or shifted leaf springs, broken center bolts, rust or stretching on the U-bolt threads, or gaps between the spring pack and axle. Any movement between these components indicates immediate replacement is needed to prevent catastrophic failure.