Mack service campaign S4325 202412
Mack filed this with NHTSA as a service campaign dated Dec 9, 2024, received Jan 2, 2025, about the engine. It names 1 model year (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 communicationMack Trucks has identified that certain 2025 model year Mack Medium Duty (MMD) vehicles may have been assembled with insufficient torque on the fan hub retaining hardware. To address this issue and maintain Mack's high-quality standards, please follow the instructions below to properly retorque the fan hub retaining hardware.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| S4325 202412 | Service campaign | Dec 9, 2024 | 11012165 | 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 MD.
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 S4325 202412 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 S4325 202412 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 S4325 202412 cover?
The manufacturer filed it against 1 model year: 2025 Mack MD. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.