You'll likely need sockets for:
* Axle nut: This is usually a very large size, often in the 1 1/16" or 1 1/8" range (or even metric equivalents), but you must verify this with a socket set or a torque wrench, measuring the nut first to determine correct sizing. Don't guess on this one as it's extremely important for safety.
* Caliper bolts (front only): These are typically 14mm or 15mm, but again, check your vehicle.
* Other smaller bolts and nuts: Various smaller sizes (likely metric) will be needed for cotter pins, caliper bracket bolts, and other components depending on your specific approach to the wheel bearing replacement.
Crucially: You should consult a repair manual specific to your 1998 GMC Jimmy. This manual will provide the exact socket sizes and torque specifications needed for each bolt and nut, ensuring a safe and successful repair. Attempting this without the proper information could lead to damage to your vehicle or personal injury.
Don't rely solely on internet advice for this task. A repair manual is essential.