Transmission slipping

My 1999 Malibu LS will not shift gears right away (about 3 second delay) when I use it on heavy basis (on a paper route). All other times it works fine. What is the reason for this? Fluid bad?

How many miles on this car? Have you ever serviced the transmission? Have you checked the fluid level?

105,000 miles…I bought it at 80,000 and to my knowledge no work on it since I’ve had it…I think there is no way to check level on this car.

Assuming all things have been check and looks good. Your 4L60 transmission could be just getting tired. The forward friction plates oil circuit could be starting to shows signs of leaking. As long as it does not slip when first started up cold, you should be O.K. for awhile.

That sounds more like a delayed shift rather than “slipping” - if it is slipping you would be hitting the gas and the engine would be revving up but without feeling the power go to the wheels. Is that what is happening or something else?

If it is actually slipping then it is on its way downhill and will likely need to come out or be retired.

If it is delayed shifting there are other possibilities and the place to start would be at a local (non-corporate chain) transmission shop to have them drive it and scan it for codes.

I think you mean a 4T40. The 4L60’s were RWD and went out in mid 93. Since you have already put 25k on it and are uncertain of the service history, I would go ahead and have it serviced with a pan drop, fluid and filter change. This way the pan can be inspected for any debris. Refill and pour in a bottle of Lube-Gard in the RED bottle. Service your trans every 25-30k miles.


Actually I don’t give it gas until I feel it shift, otherwise I figure I would do harm to it. You’re right though, it does seem like delayed shifting rather than slipping because it NEVER EVER does this under normal circumstances. Even when I’m doing my route it will do this for awhile then go back to normal for awhile and so on… I wonder, does the computer have anything to do with shifting? Thanks for the help.

I’m not sure what “normal circumstances” are, but either way follow transman’s advice (above). And yes, the shifting is computer controlled.