Chevrolet Silverado 2500HD — Bolt Pattern & Wheel Fitment

2020-2024 3rd gen HD (T1XX HD / GM "Full Size C/K HD Pickup", CK20xxx series)

VERIFIED FALSE, and I independently reached the same conclusion as the first researcher: lugTorque is solidly OEM-sourced but boltPattern is not cited by any OEM document I could obtain. OEM-CONFIRMED (I downloaded and read each document myself, not relying on the prior write-up): lugTorque 140 lb ft (190 N-m) in three GM owner's manuals - MY2020 (P/N 84186886 C, printed p.456), MY2021 (P/N 84744493 C, printed p.399) and MY2022 (printed p.407) - plus GM Service Update N192285970 Rev 01, which tells dealers to tighten "the 8-wheel nuts to 190 N-m (140 lb ft) in a crisscross pattern" on a 2020 Silverado 2500 HD. The TSB is the only OEM document that states the LUG COUNT (8). Wheel sizes, offsets (44 mm on 17x7.5 and 18x8; 47 mm on 20x8.5) and tire sizes are OEM-confirmed twice, in the 2020 and 2024 editions of the GM Upfitter body builder manual, which agree exactly. NOT OEM-CONFIRMED - treat as candidate values: (1) boltPattern 8x180 / 8x7.09 in - the number is near-certain (every GM HD since MY2011 uses it, and it is unanimous across independent catalogs) but NO GM document states it. I searched, myself, both editions of the HD chassis body builder manual, the 1500/light-duty body builder manual, the Snow Plow Prep (SPPP) bulletin and the full 2022 owner's manual for "bolt circle"/"PCD"/"bolt"/"stud"/"180" - zero relevant hits. accessories.chevrolet.com, chevrolet.com/accessories, parts.chevrolet.com and gmpartsdirect.com all returned HTTP 403 to me too, via both plain HTTP and a real browser session. GM does not appear to publish bolt circle in any public primary document. (2) centerBore 124.1 mm - aftermarket consensus only; treat as approximate (124.1-125 is quoted variously). (3) threadPitch M14x1.5 - aftermarket/parts-catalog consensus only, no OEM source. CORRECTIONS I MADE TO THE PRIOR RECORD: (a) The RPO codes attached to the wheel sizes are TIRE RPOs, not wheel RPOs - the body builder manual column is literally headed "Tire RPOs" (ALS = all-season, AT = all-terrain). Labelling them as wheel RPOs would send someone hunting the wrong part numbers. (b) The prior note justified the single torque figure by saying the 2500HD "carries a full-size spare on a matching wheel, so there is no alloy-vs-steel split" - the premise is wrong (the WT trim's 17x7.5 is a steel wheel and higher trims run aluminum, so both materials exist in the lineup); the correct reason is simply that GM prints ONE figure, 140 lb ft, with no material- or position-specific variant anywhere in the book. (c) Flagged that the MY2020 citation comes from a COMBINED 1500+HD manual, so its torque row is not HD-exclusive; the HD-specific MY2020 evidence is the service bulletin. (d) Swapped in the currently-published edition of the 2024 chassis body builder manual (the "page-11-fix" file GM now links) in place of the superseded "page-40-fix" file. GOTCHAS: Do NOT carry over Silverado 1500 (T1XX) data - the 1500 is 6x139.7. Do NOT carry this 8x180 back past MY2011 - 2007-2010 GMT900 HD and earlier used 8x165.1 (8x6.5 in); mixing those is a wheel-off failure mode. The 2500HD is single-rear-wheel only; the 3500HD DRW is a different wheel entirely (17x6.5, LT235/80R17E) and the shared owner's manual adds a dual-wheel-only retorque schedule at 160/1 600/10 000 km (100/1,000/6,000 mi) - that schedule does not apply to the 2500HD. The "137" in the DRW row's Offset column is dual-wheel mounting data, not a conventional SRW offset, so do not reason from it. COVERAGE GAPS: (1) MY2023 and MY2024 owner's manuals - I could not retrieve them either. GM's DAM only serves MY2020-MY2022 at the working path, and ~30 URL permutations across chevrolet.com, contentdelivery.ext.gm.com and gmc.com (Sierra HD equivalent) all 404'd. The 140 lb ft figure for 2023-2024 therefore rests on three unchanged 2020-2022 manuals plus the 2024 body builder manual showing an unchanged wheel package - strong, but not directly cited for those two years. (2) The MY2024 Silverado HD ZR2 / ZR2 Bison wheel-and-tire package (18-inch wheel with a 35-inch tire) is NOT covered by any OEM source I could read - the 2024 body builder chart was revised 02/03/2023, before the HD ZR2 was announced, and it lists only 17x7.5/18x8/20x8.5. Do not apply the 20x8.5/+47 numbers to a ZR2. GENERATION BOUNDARY: 2020-2024 is a cataloging window, not a spec change. GM itself still links the SAME 2024-dated HD chassis body builder manual from its MY2025 and MY2026 body-builder pages (I verified this by scraping those pages), so the factory wheel/offset/tire package continues unchanged into MY2025-MY2026 of the same T1XX HD generation. If checkfitment adds later model years, they belong with this record, not a new one.