WEAK STEERING
Weak link: Stock steering for straight-axle trucks
Models affected: All straight-axle trucks and SUVs
What happens: Stephen Watson at Off Road Design says that stock GM steering does not function correctly in twisty off-highway situations when the vehicle is equipped with a suspension lift of more than 4 inches. Further, the stock GM tie rods are very susceptible to trail damage.
Sturdy fix: Install a crossover steering system, like Off Road Design's kit (shown). They offer a kit for the 10-bolt, Dana 44 and Dana 60 axles. If you use a crossover steering system with a straight drag link, remember to use Missouri Off Road's engine crossmember to avoid contact between the drag link and the factory crossmember. Off Road Design offers a couple of different levels of tie rods for stock applications, as well as a high-steer kit to mount the tie rod on top of Dana 60 knuckles, above the leaf springs, to keep it out of harm's way. Missouri Off Road Outfitters offers heavy-duty drag links for crossover steering setups and heavy-wall tie rods for either stock or crossover steering.
Contact: Missouri Off Road Outfitters, Off Road Design.
LOW GROUND CLEARANCE
Weak link: Corporate 14-bolt full-float rear-axle ground clearance, thin diff cover and weight
Models affected: All GM 14-bolts
What happens: Overall, everyone is in agreement that the 14-bolt is an excellent rear axle, but they do suffer from minimal ground clearance, paper-thin rear differential covers and they're heavy overall.
Sturdy fix: Shaving and smoothing the bottom of the axlehousing, usually with a Sawzall and grinder, can improve ground clearance. Replacing the differential cover with a Missouri Off Road Rock Bruiser diff cover will eliminate issues with the stock cover (shown, with a Missouri Off Road Over The Top axle truss). Replacing the drum brakes with discs will shave about 100 pounds from the total weight of the axle, and Off Road Design offers a bracket kit for 14-bolt full-float axles that allows the use of General Motors 3/4-ton front rotors and calipers.
Contact: Missouri Off Road Outfitters, Off Road Design.
POOR ARTICULATION
Weak link: The IFS front suspension
Models affected: '88-and-up
What happens: This suspension offers a great ride, but suffers from poor articulation and durability when used for even moderate off-highway travel.
Sturdy fix: For serious off-highway performance, replace the IFS with a solid front axle using a conversion kit like the one offered by Off Road Unlimited. It includes all of the necessary bracketry and hangers. ORU offers all of the components to complete the swap, including leaf springs from 2 to 12 inches in raised height in 2-inch increments, brake lines, front CV driveshaft and yoke, complete Dana 44 or Dana 60 axles and even a crossover steering kit.
Contact: Off Road Unlimited.
BAD SHACKLES
Weak link: Front leaf-spring shackles and bushings
Models affected: All solid-axle trucksWhat happens: The front shackles on straight-axle vehicles are notoriously weak and the bushings wear out quickly.
Sturdy fix: Off Road Design offers a heavy-duty front-shackle kit (shown) that strengthens this area with a stronger, harder-compound bushing, a swap to 1/2-inch-diameter shackle bolts (stock are 7/16-inch diameter) and 3/8-inch-thick shackle plates (stock are about 1/4-inch thick). They're also greaseable, so you can keep the pivots lubed.
Contact: Off Road Design.
T-CASE INTERNALS
Weak link: NP203 transfer case internals
Models affected: '73-'79, all duty levels
What happens: The NP203 has problems with chain breakage, as well as differential-assembly failure.
Sturdy fix: Rebuild the unit with quality aftermarket components, or swap in a beefier NP205 using adapters available from Off Road Design and others.
Contact: Off Road Design.
WEAK RAG JOINT
Weak link: Steering-shaft rag joint
Models affected: All straight-axle models
What happens:The rag joint that connects the steering shaft to the steering box wears out and breaks, leaving you with no steering control.
Sturdy fix: Either replace with a new rag joint, or better yet, replace the whole steering shaft with a dual U-joint telescopic heavy-duty steering shaft from Borgeson Universal. This kit's design eliminates the rag joint altogether.
Contact: Borgeson Universal.
WIMPY LINKAGE
Weak link: SM465 manual transmission linkage
Models affected: Pre-'85, all duty levelsWhat happens: When the vehicle is twisted up off-highway, the pre-'85 manual clutch linkage tends to bind up.
Sturdy fix: Beginning in '85, GM switched to a hydraulic assembly that cured the binding problem. This hydraulic clutch assembly can be retrofitted to the pre-'85 units.
Contact: Your local salvage yard or GM parts supplier.