Frank Biolsi, Author at Transmission Digest
Diagnose with Data

Some folks have not had an opportunity to use data recordings as a diagnostic tool. When you first start looking at recordings, there appears to be so much data that it’s hard to find the answers. There are a few techniques I have found very useful in getting the information I need. The “before” graphs show the readings used to verify the complaint and diagnose the problem.

Small Tips for Big Rebuilding Headaches Part 2

Many of you who call us for technical support and advice ask for items that fit this description. While we are always open to new ideas for new products that solve root-cause problems, there are times when these parts are already readily available and reasonably priced. It’s just that few rebuilders know about them. So, here are a few brief tips for you on some of the parts you asked for and where you can find them.

Small Tips for Big Rebuilding Headaches

Small things are often the cause of problems that can create grief in our everyday operations. Those seemingly inconsequential items can and on occasion do bring production to a halt. What seemed like nothing of great importance now becomes the stopper.

Look Before You Leap (into a CD4E)

How many times has your mother told you to look before you leap? It was good advice when you were a kid, and it’s even better advice if you’re about to tear apart a modern transmission – especially when the transmission in question is a CD4E.


AFL stands for actuator feed limit and another fourth lost.

Perhaps you’ve already chased this on a 4L80-E or in a somewhat similar fashion on a 4L60-E. Here’s how badly it can go. You take in your buddy’s 4L80-E with converter codes and failsafe operation beginning to appear at normal mileage. Make it worse: It’s a good buddy, so you give him a break on the price. You scan the unit, drive it, do a careful rebuild, check TCC-related areas, put in a good converter, fill it with your preferred red fluid and reset the computer.