Mack service campaign S4579 092025
What it saysMack Trucks has identified that certain truck models may have been assembled with incorrect center bearing mounting hardware and could have been torqued incorrectly. NHTSA’s full summary ↓
Mack filed this with NHTSA as a service campaign dated Sep 1, 2025, received Oct 1, 2025, about the power train. It names 3 model years (2026). 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 truck models may have been assembled with incorrect center bearing mounting hardware and could have been torqued incorrectly. Improper torque can increase the risk of hardware failure. To address this issue, please follow the instructions in this document to replace and correctly torque the center bearing and center bearing mounting bracket hardware.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| S4579 092025 | Service campaign | Sep 1, 2025 | 11023461 | PDF, 461 KB |
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: 2026 Mack Anthem (an); 2026 Mack Granite (gr); 2026 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.
More bulletins about the power train
Source: same model, same component group4 other manufacturer communications filed against these Mack models under the same component group (power train), newest first.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| S4574 072025 | Service campaign | Jul 1, 2025 | SC - Mack Trucks has identified that certain truck models may have been assembled with incorrectly torqued interaxle prop shaft U-joint hard… |
| S4558 202506 | Service campaign | Jun 18, 2025 | Mack trucks has determined that certain model year 2021-2024 PI models built with 4.19 rear axle ratios could experience elevated axle oil t… |
| S4088 202409 | Service campaign | Oct 1, 2024 | Service Campaign: Interaxle Driveline Torque |
| S0488 202407 | Service campaign | Jul 24, 2024 | Service Campaign: Interaxle Driveline Torque |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Mack, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Mack S4579 092025 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 S4579 092025 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 S4579 092025 cover?
The manufacturer filed it against 3 model years: 2026 Mack Anthem (an), 2026 Mack Granite (gr), 2026 Mack Pinnacle (pi/pn). Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.