Technical Service Bulletin S4558 202506 — 2021 MACK PINNACLE (PI/PN)
POWER TRAIN
Bulletin Details
| TSB ID | S4558 202506 |
| Manufacturer | |
| Vehicle | 2021 MACK PINNACLE (PI/PN) |
| Component | POWER TRAIN |
| Communication Date |
Bulletin Summary
Mack trucks has determined that certain model year 2021-2024 PI models built with 4.19 rear axle ratios could experience elevated axle oil temps under high road speeds. To correct this issue the 4.19 ratio carriers need to be swapped to 3.79 ratio carriers. Follow the instructions below to replace both carriers with new ones.
About Technical Service Bulletins
A Technical Service Bulletin (TSB) is a document issued by a vehicle manufacturer to its dealers, describing a known issue with a specific vehicle or set of vehicles and the recommended procedure to fix it. Unlike recalls, TSBs are not mandatory and are typically only performed if an owner reports the related issue. However, TSBs can be an indicator of common problems with a vehicle.
Other TSBs for the 2021 MACK PINNACLE (PI/PN)
CBR-2360 202404
SEAT BELTS
PSM23m2na71
POWER TRAIN
KC-2140
PARKING BRAKE
KC-406
FUEL SYSTEM, DIESEL
SNM22-001
ENGINE AND ENGINE COOLING
SNM21-006
COMMUNICATION:MANUFACTURER TELEMATICS
S7601
ENGINE AND ENGINE COOLING
S7597
ENGINE AND ENGINE COOLING
FSB 511-010
SERVICE BRAKES, AIR
KC-2061
SUSPENSION