Toyota Tundra Owners Hit Rough Patch With 6-Speed Transmissions
At least ten 2007 Toyota Tundra owners at TundraSolutions.com (TS) have posted experiences of six-speed transmission anomalies that all share a common symptom. The transmission randomly rough-shifts for several seconds, making the truck feel like it's riding on a roadside rumble strip. Hence, the problem has been given the informal name 'rumble strip' transmission issue.
TS members in the discussion thread recount that Toyota dealers who have serviced impacted trucks have acknowledged the issue, saying it's caused by the truck's torque converter not disengaging properly during gear changes. The torque converter takes the place of a clutch in an automatic transmission. It smoothly transitions gear shifts and disconnects the driveline from the engine at stops, so the engine doesn't stall.
Owner anecdotes also describe that the Tundras have quickly had their transmissions replaced with new or remanufactured units - to the satisfaction of most owners.
A Toyota service tech I spoke to at a dealer in the Dallas, Texas metro area said he was well aware of the problem but had only seen one truck so far with the issue at his dealership.
Asked if Toyota's U.S. headquarters is aware of the Tundra's transmission issue, Toyota spokesperson Joe Tetherow confirmed to PickupTruck.com that the issue exists and that it's been traced back to the torque converter.
Mr. Tetherow says going forward only the torque converter of impacted trucks will be replaced, instead of the entire gearbox. He was not able to quantify the potential number of trucks affected, but did say that it's not a safety or design issue.