LOS ANGELES — Toyota's Tundra pickup was hit with a double whammy last week.
Angry consumers are peppering the Internet with complaints that the torque converter in the 2007 Tundra's six-speed transmission has problems disengaging during gearshifts — a problem that Toyota acknowledges.
Meanwhile, the Tundra 4x4 model took a broadside from Consumer Reports magazine, which rated it "below average" in projected reliability.
Toyota thought it had put the redesigned Tundra's teething problems in the rearview mirror. First there was a batch of defective camshafts. Then it received a four-star rating in NHTSA crash tests, one star less than its Detroit rivals.
The latest quality snarl involves a vibration coming from the transmission when changing gears under gentle acceleration or deceleration.
Toyota Motor Sales officials have nicknamed the problem "the rumble strip" because the slippage causes vibration similar to the sensation of driving over the wake-up strips at the side of highways.
The rumbling usually lasts several seconds. But the problem sometimes worsens to the point that some owners can't shift into certain gears.
The problem has been reported only in six-speed transmissions, which are linked to the popular 5.7-liter V-8 engine. Since the 2007 Tundra's February launch, the 5.7-liter engine has been installed in 70 percent of about 135,000 Tundras sold. That means the problem could affect nearly 100,000 vehicles.