One of the most common (and most frustrating) problems that happens to the 4L60E 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 4L60E and cause this problem. It probably goes without saying, but if you put the vehicle into second gear manually, you’ll still be able to get to where you need to go.
If you end up with a bad sprag, the 4L60E won’t be able to shift into 3rd or 4th gear. It provides a direct connection between the input housing and the input sun gear. Without being able to lock, it won’t be able to facilitate the transfer of energy to the upper gears and the transmission will remain in 2nd gear.
3/4 Clutch Pack
Your 4L60E 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. The YouTube video below shows someone going through that exact situation.
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.