The 1999–2006 Silverado/Sierra cab corners are a known rust spot. Here’s how to DIY a weld-in patch repair.
Tools Needed:
- MIG welder
- Angle grinder with cutting and flap disc wheels
- Body hammer
- 3M Weld-Thru Coating II
- Seam sealer
Steps:
- Remove door, or protect it with welding blanket
- Mark cut lines – cut out rusted metal leaving 1" of good metal overlap
- Trim reproduction patch panel to fit
- Apply weld-thru primer to mating surfaces
- Clamp panel in position and tack weld
- Check door gap before completing welds
- Complete stitch welding
- Grind smooth, seam seal, prime, paint
Cost:
- Reproduction cab corner panel: $60–$150
- Materials (primer, sealer, paint): $50–$100
- Total DIY: $110–$250
Professional shop: $600–$1,500 per corner
Have you done a cab corner patch on your GMT800? Share your tips!