There is a known problem with 2015, 2016, 2017, 2018 and 2019 GMC Sierra transmissions. Does your Sierra shudder, shake or suffer from delays shifting from first gear to second gear, or from second to third?
Many GMC Sierras built after 2015 are known to provide very hard and difficult shifting, slipping gears, and overheating. Many of these vehicles have one of the 6L80, CL80, 6L90 or CL90 family of transmissions. There are a variety of symptoms, including very hard and difficult shifting, slipping gears, overheating and more. This is usually caused by a problem with the Pressure Regulator System (PRS), which uses valves, springs, and ball bearings, and is responsible for maintaining the hydraulic pressure required for the smooth operation of the automatic transmission.
Frequently, GMC Sierra owners complain of:
Hard shifting – owners claim that the vehicle shifts so rough that it almost feels like they have purchased a used vehicle rather than new.
Trouble downshifting – many buyers purchased the GMC Sierra to use for towing or carrying heavy items, which suggests a heavy load.
Sudden jerking – newer vehicle (as recent as 2019) owners have complained about this issue, especially when the vehicle is cold first thing in the morning. The jerking has even effected some GMC Sierras with low mileage.
This is caused due to a problem with the Pressure Regulator System (PRS), which uses valves, springs, and ball bearings, and maintains the hydraulic pressure required for the smooth operation of the automatic transmission. The PRS contains some plastic parts and low-quality metal components that can wear out or break fairly easily, creating excessive wear and tear on the valve body.
GM is aware of some problems with the GMC Sierra truck transmission malfunction and has notified dealers of a upshift problem. In October of 2022 GM sent out Service Bulletin 22-NA-185, addressing the faulty transmissions including GMC Sierras. It also specifically stated "The transmission upshift malfunction can occur in the following conditions":
"During the first 2-3 upshift after the vehicle has been sitting, engine off for several hours. This condition may be caused by air that is trapped in the 3-5-R clutch assembly. When the first 2-3 upshift is made this trapped air is purged and the following 2-3 shifts will be normal with no flare.
When transmission ATF temperature is less than 85 degrees F (30 degrees C). This 2-3 upshift issue can occur until the ATF temperature warms."
If you live in Sacramento and are having these problems with your GMC Sierra, bring it into our shop and let us determine exactly what's going on. We can get your transmission fixed and put you back on the road!
Waves offers a vast set of services and solutions that help you achieve the desired result.