According to the technical service bulletin TSB PIP4304A, the 2008 Hummer H2 equipped with either the 6L80 transmission or 6L90 transmission can have one or more of the following symptoms; slipping in 1st, 2nd, 3rd or 4th gears. Drivers might also experience a pronounced 2 – 3 second delay between the time they shift from park and into drive. The following diagnostic trouble codes/DTC will also accompany this problem; P0878, P2714 & P2723.
What Transmission Do I Have?
This technical service bulletin was designed to assist technicians in determining the proper course for repair of this issue. For example, if the transmission fluid appears dirty and dark, with evidence of clutch debris on the dipstick or in the transmission pan, then the 1 – 2 – 3 – 4 clutch plates will have to be replaced. The entire transmission will have to be inspected for signs of damage from clutch debris as well. In addition, the transmission cooler will also need to be flushed out.
If none of those symptoms are present, yet the problem persists, then the control solenoid valve, transmission control module assembly, and the 1 – 2 – 3 – 4 clutch plates will all need to be replaced.
Given the amount of labor time that it will take to perform this repair, it might be simpler to have the entire transmission rebuilt. However, if you want to keep your Hummer on the road for as long as possible, then you’ll need to upgrade to a remanufactured 6L80 transmission or remanufactured 6L90 transmission from a company like Street Smart Transmission.
What Transmission Do I Have?
They completely reengineer each transmission to address factory design flaws, like this one. Then they dyno test each transmission before it leaves the factory to ensure that it performs properly right out-of-the-box. And you get a three year/unlimited mile nationwide warranty to protect you and your investment down the road/trail in the middle of nowhere. If you would like to learn more, simply click here.
