One of the most common (and most frustrating) problems that happens to the 4L80E is when it loses 3rd and 4th gear at the same time. This leaves you driving around a car or truck that screams down the road. So, what causes the no 3rd gear or 4th gear problem? Below are some common things that fail in the 4L80E and cause this problem. It probably goes without saying, but if you shift the vehicle into second gear manually, it will still move.
Shift Solenoids
If you are experiencing no 3rd or 4th gear, it can often be caused by the shift solenoids. If they can’t engage a gear properly, the transmission won’t be going into that gear. In this case, it’s probably going to be the 2-3 shift solenoid.
3/4 Clutch Pack
Your 4L80E has a set of clutches that work with both 3’rd and 4’th gear. It’s referred to as the 3-4 clutch pack. A bad 3-4 clutch pack can certainly cause the 3’rd and 4’th gear to stop working. In fact, once the transmission “shifts” into third, it’ll feel like you lost the whole thing. You can shift into second to get yourself home. Just be careful on the highway.
Before they go all the way out, usually you’ll feel the transmission take a long time to shift into 3rd gear. This’ll be because the clutch pack is barely engaging. It’s often referred to as a “lazy shift”. If you give it too much throttle it may not engage at all. Either way, it’s a symptom that the 3-4 clutch pack is getting ready to give up entirely.
Bad Electronics
The service engine soon light doesn’t just tell you what is going on with the engine, it also gives you invaluable information about what is going on with the transmission. If your transmission happens to be having an electrical problem, it could very well disable the third and fourth gear. If you have a service engine soon light on, it’d be a great place to start looking for your no 3rd or 4th gear problem.
No matter what caused your 4L80E to lose third and fourth gear, good luck fixing it.