A whining, growling or grinding sound may be heard on some 2017-2019 Colorado and Canyon models during acceleration or deceleration when traveling from 20 mph (32 km/h) to highway speeds. There may be a machining issue that creates a step on the surface of the carrier bearing bore in the rear differential housing. Affected models are equipped with the 2.8L diesel engine (RPO LWN) or 3.6L V6 engine (RPO LGZ) and a 3.42 rear axle ratio (RPO GU6) and were built from start of production to June 17, 2019.
If these conditions are found, follow the diagnostic information for a rear differential noise in the appropriate Service Information. If the source of the noise is determined to be coming from the rear differential carrier bearings, disassemble the axle assembly and inspect the surface of the carrier bearing bore in the differential housing. (Fig 18)
Fig. 18
If the mating surface contains machining imperfections or has a step on the surface (Fig. 19), replace the axle assembly.
Fig. 19
If the bearing mating surface is free of any imperfections, replace the carrier bearings only. Be sure to use the designated special tools listed in the Service Information in order to properly remove and install the bearings.
Refer to Bulletin #20-NA-034 for additional information and part numbers.
– Thanks to Tom Holecek
