4R75E Archives - Transmission Digest
Ford 4R75E Slipping in Third Gear

Complaint: The vehicle may come into the shop slipping in third gear, upon disassembly of the transmission the direct clutch is found to be badly burnt. Further disassembly reveals the bottom of the 2-3 accumulator piston has blown out, refer to figure 5. Cause: The damage to the 2-3 accumulator piston will allow forward clutch

Debris, Melted Insulation Cause Two Codes to Set

About two months ago a customer brought in his 2006 Ford E350 Econoline van equipped with a 5.4L engine and a 4R75E transmission for an evaluation. His concern was that the check-engine light was on and the transmission seemed to shift hard at times. We always begin our evaluation with a battery and charging system test with a Midtronics electrical system analyzer, and we scan all modules for codes using a Snap-on Verus Pro if we are not using an OE scan tool. After a quick visual inspection of the vehicle and checking the engine oil level, we will proceed with the road-test.

Critical Wear Areas & Vacuum Test Locations

Critical Wear Areas & Vacuum Test Locations

A Fly on the Wall

When transmission parts fail or have problems, I often think about the decisions made along the way that resulted in the problematic part being used in production. A common sight at many transmission benches these days is a “cracked” separator plate found in 2001 and newer 4R70W/4R75E units. There is more to this story than just the cracked plates discovered during the rebuild, and it started long ago when the decision was made to eliminate a valve-body stiffener plate. I would love to have been a fly on the wall back then, listening to the reasons why it was OK to eliminate the stiffener plate.