Frequently Asked Questions About GMC General Truck Hub Adapters

What GMC General truck years are these hub adapters compatible with?

Our hub adapters are designed to fit GMC General trucks from 1977 to 1989. These adapters work with both single and dual rear wheel configurations. However, it's important to verify your specific axle type and bolt pattern before ordering. Most GMC Generals use an 8-lug pattern, but some specialty models may differ. If you're unsure about your truck's specifications, check your owner's manual or contact us with your VIN for verification.

Are these hub adapters made from steel or aluminum, and which is better for heavy-duty use?

We offer both steel and aluminum hub adapters. Steel adapters are typically more affordable and extremely durable, making them ideal for heavy-duty commercial applications and frequent towing. They can handle higher torque specifications but add more weight. Aluminum adapters are lighter, reducing unsprung weight and improving fuel efficiency, while still maintaining excellent strength for most applications. For trucks regularly hauling maximum loads or operating in severe conditions, we recommend steel. For highway driving and moderate loads, aluminum provides the best balance of performance and weight savings.

Do I need special tools or professional installation for these hub adapters?

While professional installation is always recommended for safety, experienced mechanics can install these adapters with standard shop tools. You'll need a torque wrench capable of 450-500 ft-lbs, a heavy-duty impact wrench, and proper jack stands rated for commercial trucks. The process involves removing the existing wheels and drums, cleaning the mounting surfaces thoroughly, and torquing the adapters to manufacturer specifications. Installation typically takes 2-3 hours per axle. Critical steps include proper centering and following the specific torque sequence to prevent vibration issues.

What's the difference between hub-centric and lug-centric adapters, and which do I need?

Hub-centric adapters have a precisely machined center bore that matches your truck's hub diameter, providing a perfect centered fit and reducing stress on the wheel studs. Lug-centric adapters rely solely on the lug nuts for centering. For GMC General trucks, we strongly recommend hub-centric adapters as they eliminate vibration issues common with lug-centric designs, especially at highway speeds. Hub-centric adapters also distribute weight more evenly and reduce wear on wheel studs. Most GMC Generals have a 4.56" center bore, but always verify your specific measurement before ordering.

Will these adapters affect my truck's track width or require longer wheel studs?

Yes, hub adapters will increase your track width by the thickness of the adapter, typically 1.5" to 2" per side. This wider stance can improve stability but may cause tires to extend beyond fender wells, potentially requiring fender flares in some states. Most of our adapters come with new, properly sized wheel studs pre-installed. However, if you're stacking adapters or using aftermarket wheels with thick mounting pads, you may need longer studs. We recommend maintaining at least 1.5 times the stud diameter in thread engagement for safety. Always test fit and verify proper thread engagement before final installation.