Example of a stray nut wedged into the transmission mount.
This bulletin applies to 2015-2022 Chevy Colorado vehicles equipped with a 6L50 MYB or 8L45 M5T transmission.
On a rare occasion, a vehicle may have a vibration at idle in gear or at very low speeds. Inspect for a stray nut, rock or other debris wedged between the rubber and metal portions of the transmission mount.
Using a borescope will aid in inspection. Loosen the mount fasteners and manipulate the mount to allow removal of any stray debris.
If this does not resolve the vibration or if no debris is found, follow vibration diagnostics.
Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety ofspecialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.
