Mack service campaign S4373 022026
Mack filed this with NHTSA as a service campaign dated Feb 26, 2026, received Mar 3, 2026, about the structure. It names 2 model years (2025). A service campaign is not a safety recall — there is no NHTSA campaign number and no federal requirement — but it is usually work the manufacturer pays for on the vehicles it names; the dealer checks the VIN against the manufacturer’s list.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationSC - Mack Trucks has determined that certain Mack sleeper cab assemblies were possibly manufactured with an insufficient number of welds across the rear flange of the upper header
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| S4373 022026 | Service campaign | Feb 26, 2026 | 11029455 | not yet checked |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themAlso filed against: 2025 Mack Anthem (an); 2025 Mack Pinnacle (pi/pn).
None of these model years has a page on this site (it covers EPA-certified cars, trucks and SUVs from 2016), so the bulletin is listed here on its own.
Common questions
Source: NHTSA, 49 CFR 579.5Is Mack S4373 022026 a recall?
No. A service campaign is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls.
Is the S4373 022026 repair free?
A service campaign is usually paid by the manufacturer on the vehicles it names, within the terms and time limit the document sets; the dealer checks the VIN against the manufacturer’s list.
Which vehicles does S4373 022026 cover?
The manufacturer filed it against 2 model years: 2025 Mack Anthem (an), 2025 Mack Pinnacle (pi/pn). Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.