The first and cheapest step is to have the computer checked for trouble codes.
The DeVille could have low transmission. Or the internal transmission bands or valves could have failed. The transmission will most likely need a rebuild.
This problem could be the linkage in the transmission. The transmission could also be going out and would need replaced.
my drive and 3rd not working what is causing this promblem is their a a promblem with the transmission
A 4l60e transmission uses a series of bands and hydraulic pressure to downshift. This changes the gearing ratio inside of the transmission which is then output to the drive shaft and wheels.
Its either in need of transmission fluid a fluid change or the bands are strechted
The transmission is the same.
The transmission will need to be replaced and it isn't any fun i just did the same thang my self
There is a problem with the valve body in the automatic transmission. It may stay like that, or it may get worse - no accurate prediction can be done without pulling the transmission apart to see what the cause is.
When a auto trans is cold the clutch bands hold better but after they get hot they slip. Find a transmission shop asap.
The transmission
this is a typical problem with berettas, for some reason the bands in the transmission will not hold out after several miles are on the car, have the bands tightened or replaced, and you wont have any more problems
Could be a universal joint. If front wheel drive, it could be the constant velocity joint. I am assuming you have an automatic transmission. If it is a standard transmission, it could be the throwout bearing.