TCC Archives - Transmission Digest
6R80 whirring noise: TCC slip or engine surge?

About a month ago, we at Certified Transmission received a 2015 Ford Expedition 4WD at the shop. It was equipped with a 3.5L Turbo V6 engine and a 6R80 transmission. The complaint read, “RPMs fluctuate up and down and there is a whirring noise.” The vehicle was brought to us by one of our wholesale

Sonnax unveils valve kits for ten-speed Ford, GM transmissions

Sonnax highlights its valve kits for Ford and GM ten-speed transmissions. The first of these is a line of oversized main pressure regulator valve kits #105740-20K (pictured above) for GM 10L60/80/90 (Gen. 1) and Ford 10R60/80/90/140 transmissions and #105740-21K for GM 10L60/80/90 (Gen. 2) transmissions. The company says these kits can recover hydraulic control and

Sonnax-105740-20K-600
Persistent P2757 DTC

When the vehicle was scanned, a P2757 code was pulled which is a solenoid performance code for the SLU (TCC) solenoid.

Ins and Outs of Torque Converters

Plotting the pathways of the oil that enters and exits the converter is not an easy task if you are only looking at the parts of the converter. Adding a stator support and an input shaft to the converter parts makes this task somewhat easier.

You Gotta Be Kiddin’

Many of these vehicles have had defective OE converter-clutch linings causing the slip. Many of these have since been resolved so this issue doesn’t come up as much on ATSG’s technical help as it used to.
But when they do come in, we explain the way to verify a defective converter lining. It is by checking TCC pressure on the transmission’s one-and-only pressure tap.

Analyzing Clues Solves TCC Mystery

The vehicle was a 1995 Ford Ranger 2WD, equipped with a 4R44E transmission. It had originally been repaired by a local transmission shop that had removed the unit and rebuilt it in house, though we had no knowledge of what the original complaint was at the time. After their repair, it would set a P0741 (TCC stuck off), OD light flashing etc. They’d had the vehicle for quite some time but then decided to purchase a remanufactured unit from one of our distributors when repairing the rebuilt unit was unsuccessful. After installation of the remanufactured unit, the same code and symptoms returned. It was then that the vehicle was brought to our shop for diagnosis.

Information, Equipment & Experience

When a vehicle comes into your shop for repair you need to determine whether you have access to service information, the equipment needed to make the repair and the experience to repair it. As you read this article you will see just how challenging a transmission replacement sometimes can be. In this particular situation the service information was misleading and special equipment was needed to make the repair. This was one job that turned into yet another learning experience for me.

A Significant Departure – the 48RE Transmission

For many of you who have been working on the Dodge/Jeep RE-series transmissions, you are more than likely all too familiar with an engine-stall condition when reverse is selected. This problem usually reveals itself when the transmission is hot. The usual cause is a defective pump. From time to time a restricted cooler would be the culprit, but in most instances it has been the pump.

RAV4’s Transmission Dilemma Presents Challenge

The code chart for the P0770 shift-solenoid-E malfunction has a simple description of the diagnostic trouble code (DTC) checking condition: It says that the lockup does not occur during lockup range (50 mph) or lockup remains on during lockup-off range. The possible causes listed are that the shift-solenoid valve is stuck open or closed, the valve body is blocked or stuck, or the clutch is locked up.

Troubleshooting Lockup Issues

The first thing that you need to know is the type of lockup system you are working with. The lockup configuration will be either a conventional system with single or multiple clutches or a clutch-pack system such as those found in the 722.6 Mercedes and Jatco RE5R05A converters. The 722.6 Mercedes converter was covered in the May and June 2010 issues of Transmission Digest, and the Jatco RE5R05A was covered in the October 2011 issue. This article will focus on the conventional clutch setup.

Finding the cause of Honda 740 codes

Many converter shops have reported having Honda converters returned to their shops because of 740 codes. In most instances, the remedy was to install a new OEM converter.

Toyota U341E/F

In the Import section of ATSG’s “Shifting Great in 2008” training seminar, one subject that was handled in the Toyota U341E/F segment of the seminar was the elusive code P0770. What makes this code so elusive is that it points to a fault for shift solenoid E. The technician tries to determine which is shift solenoid E and cannot. Nor can the technician determine whether the code indicates an electrical problem or a mechanical one.