{"nhtsa_id":11020159,"type":"service_campaign","type_name":"Service campaign","date_added":"2025-07-03","date":"2025-06-18","document_id":"S4558 202506","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN","mfr_system":null,"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.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11020159-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11020159-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11020159","components":[{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"MACK","model":"PINNACLE (PI/PN)","year_from":2021,"year_to":2024,"match":"base","vehicle_ids":["2021_mack_pinnacle","2022_mack_pinnacle","2023_mack_pinnacle","2024_mack_pinnacle"]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}