GM released a Gen-3 service valve body for 10L60/80/90. It improves robustness and sediment control, removes the auxiliary body, relocates key solenoids, simplifies harnessing and flow, deletes the internal TBV lineup on certain RPOs, and includes a revised bolt kit. First field units appeared around Aug 2025; bulletin issued Oct 29, 2025.

Truck:  2024 Chevrolet Silverado 1500 ZR2 Goal:  Fit the tallest tire possible without any modifications  (no trimming, no spacers, no level kit) and document real‑world results. TL;DR It fits:  An LT285/75R18 (~35")  mounted on OEM 18" ZR2 wheels fits without trimming  for normal driving. Edge case rub:  At full steering lock while reversing into a driveway , there is a faint rub only as the suspension compresses over the bump . Daily driving and forward lock tests were clea

Swapped my 2024 Silverado 1500 ZR2 from 275/70R18 to the exact LT285/75R18 E tires used on the Silverado EV Trail Boss. Fitment is clean—only a faint rub at full lock in reverse as the suspension compresses; no trimming yet. The big question is PSI. Don’t copy the EV’s ~56 psi placard (that truck’s ~3,000 lb heavier), and don’t stay at stock ~38 either. With LT-E you set pressure by load: start 46–48 psi cold empty; 58–62 psi rear when towing; fine-tune via hot-rise/tread che

Bulletin:  GM Service Bulletin # 25-NA-202  (Oct 21, 2025) — “LZ0 Turbocharger Replacement.” Vehicles:  2023–2026 Silverado/Sierra 1500 (LZ0), 2025 Tahoe/Suburban/Yukon with LZ0. The Issue? GM notes a portion of LZ0 turbo failures are associated with incorrect engine oil and/or low oil level . Translation: your turbo’s life hinges on using the exact diesel spec  and keeping the sump properly filled. (Bulletin # 25-NA-202 summary.) What “wrong oil” means on the LZ0 The 3.0L Du

GM bulletin 25-NA-307 (LZ0 3.0 Duramax, 2025–2026) links bellhousing-area noise + MIL/P06DD to excessive crankshaft end play (possible thrust-bearing failure). Dealers should measure end play at the crank pulley bolt with a dial indicator; spec is 0.084–0.316 mm (0.0033–0.0124 in). Expect to pay diagnostic time for the check; if out of spec, repairs proceed per SI.

GM has issued TSB #25-NA-255 for 2021–2024 trucks and SUVs with the 10-speed. Instead of replacing the valve body for P0747, the fix now calls for a new feed-limit valve, spring, and spacer plate—marking a major shift in how dealers handle this common transmission failure.

Release:  September 2025 • Bulletin:  N252508341 • Applies to (LM2 3.0L Duramax):Chevrolet:  Silverado 1500 (2021–2022), Suburban...

Release:  September 2025 • Bulletin:  N252508340 • Applies to:  2023 Chevrolet Silverado 1500 / 2023 GMC Sierra 1500 with LZ0  3.0L...

You’ve seen the window sticker. You’ve read the marketing. And if you’re like me, you’ve probably asked yourself: “Okay, but can this...

P2C7A on the 3.0 Duramax means the SCR/NOx catalyst isn’t meeting efficiency. Learn the real causes, exact diagnostics, and fixes for LM2/LZ0.

GM has released Service Update #N252510321  for select Cadillac, Chevrolet, and GMC vehicles. This is a phased launch  rolling out August...

If you’ve been driving your 3.0 Duramax-equipped truck or SUV, you're likely familiar with the frustration of a Diesel Exhaust Fluid...

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For many 3.0L Duramax owners, especially those with 2023+ LZ0 models who frequently tow, a new and deeply frustrating phenomenon is...