Asked in GMC Sierra
GMC Sierra

Why wont your 92 sierra shift out of first gear?



User Avatar
Wiki User

Most likely cause is that the auto transmission is low on fluid. The only accurate way to check the level of transmission fluid is to have the engine running (at normal operating temperature - like after a 10 mile trip) and check that fluid level. If it's low, add as required, but a little at a time. An overfilled transmission can be just as harmful as one that is running low on fluid.