GM Torque Converter and 8 Speed Transmission Problems

GM issued TSB 18-NA-355 to address “torque converter clutch (TCC) shudder conditions on 8L45 and 8L90” eight-speed automatic transmissions. The proposed solution was a new fluid flush, which appears to fix the issues for some customers, who have reported a dramatic change in shift quality after swapping out the juice. If the flush doesn’t fix the issue, the next step may be to replace the torque converter, which could be glazed.

GM 8 Speed Transmission Lawsuit

A year after the initial class-action lawsuit, The General sought to have it dismissed. The lawsuit alleges GM’s eight-speed automatic transmissions may shift violently into gear, and the filing further claims the problems are caused by some type of hydraulic systems failure, which can wear down the gears and – as mentioned earlier – allow metal shavings to become caught within the transmission.

Plaintiffs say that the fact that GM sent TSBs to dealerships are an indication the automaker has known about the defects since at least 2015. The lawsuit also claims GM’s suggested fixes, such as flushing the transmission system, are only a temporary solution.

Meanwhile, GM claims the problems with the transmission do not fall under the factory warranty, as it is a design issue  and not a manufacturing defect.

(Excerpted from) Five Ways GM Is Infuriating Its Customers Today (

Call (973) 598-1980 for a Free Consultation on Your GM 8 Speed Transmission Problem