The Heartbeat of the Transmission   How solenoid, hydraulic interaction achieves a specific gear and diagnostic tips- all in this article! The Pump With the pump being the heartbeat of the transmission and pumping fluid into its veins, it brings to life eight forward speeds, converter clutch apply and reverse. This article will provide a […]

A Look At Ford and GM’s Jointly Built 6T40 Transmission   In this last and final article of this series, we will be looking at the Transmission Adaptive Values Learn. As most know by now, this is a series of tests that are run to allow the transmission control module (TCM) to learn individual clutch […]

A Look At Ford and GM’s Jointly Built 6T40 Transmission Inside, we will be looking at the Line Pressure Specifications and continuation of our 4 part series. The line pressure tap is conveniently located on top of the transmission alongside the transmission’s fill cap. Gen 1 and 2 line pressure specification tables are provided. Specifications […]

A Look At Ford and GM’s Jointly Built 6T40 Transmission With the exception of the Low and Reverse Clutch, each clutch inside this transmission is operated by a solenoid through its respective regulating valve. With Gen 1-based models, a relatively small feed orifice was located on the line pressure supply side of the 4-5-6 Clutch […]

A Look Inside Ford and GM’s Jointly Built 6T40 Transmission Oct. 10, 2002, Ford and GM announced that they would join together to develop a new six-speed front wheel drive automatic transmission. Working on this project together would not only offer a cost-saving factor in its development, they could bring a new transmission to market sooner. Production began in […]

It Wasn’t Like That Before   When visiting WiWi’s Transmissions in Miami on a hot Saturday morning, there was a 2007 Dodge Ram 3500 with a 6.7L diesel and an AS68RC transmission (Figure 1) in failsafe along with a serious delayed engagement into reverse. A tech made some checks the night before but didn’t see […]

Finding The Torqshift Difference   Whether you have a 2-wheel drive or 4-wheel drive vehicle equipped with a 6R140 (commonly referred to as the Torqshift 6), there is only 1 valve body listed for this transmission. This is a question that is often times asked on our technical hotline as the 2 wheel drive uses […]

Can You Feel The Heat?    Things are heating up in the transmission as technology continues to roll along…   It does help when there is a code or a message display that clues you in. Some Range Rovers have an over-temp strategy that initiates when it sees ATF temperature exceed a preprogrammed threshold. Once […]

Can You Feel The Heat?   Besides shift feel, shift scheduling and converter clutch control, the TFT sensor plays a role in a variety of failsafe controls which too is manufacturer dependent.  Transmission temperature is critical, not only for the life of the fluid itself but it ultimately increases the life expectancy of the transmission. […]

Can You Feel The Heat?   Things are heating up in the transmission as technology continues to roll along.   If you have lived life for any reasonable length of time, you have come to learn that technology in general waits for no one. It seems that as soon as you buy a new electrical […]

The TF-81SC: It Moved When It Came In   There have been numerous cases on our technical hotline where a Ford 500 vehicle came into a shop for repairs requiring the removal of the TF-81SC (AF21) transmission. Once the repairs were completed or the transmission was rebuilt, the transmission did not engage into any gear […]

Does Your ZF5HP19 Go Bump and Clunk?   Audi or BMW vehicles, equipped with the ZF5HP-19/ FL/FLA may exhibit a condition of a firm engagement in the Drive position accompanied with a harsh coast-downshift. This condition will typically get more pronounced when hot. This condition seems to be more prevalent in vehicles 2003 and newer. […]

Hyundai KIA 6-Speed Transmission- Take A Look!     Hyundai has been quite forthcoming with providing technical data for its 6-speed transmission — much of which is required should the need arise to diagnose one of them. This transmission is used in both Hyundai and Kia vehicles as far back as 2009 here in the […]

Toyota A750E/F with Multiple Solenoid Circuit Faults   Toyota Tundra, 4Runner, Tacoma, Sequoia and FJ Cruiser equipped with the A750 transmission may exhibit a complaint of multiple transmission solenoid electrical circuit faults set.   Typically, to have multiple solenoid electrical faults indicates that there is a power loss or ground problems, possible compromised wiring harness (pinched, […]

FNR5/5NR5 Secondary Valve Body Variations   We have had may folks asking about the FNR5/5NR5 transmission. We decided to write up a short article about this. Read below and feel free to comment below. Complaint: When it becomes necessary to replace the secondary valve body in an FNR5/5NR5 transmission, the replacement valve body appears differently than […]

Fixing A U140E That Won’t Reverse   During an overhaul of a U140E transmission, it was determined that the original valve body needed replacement. After installation the vehicle had no reverse engagement unless the selector lever was moved around. When drive was selected, a severe delayed engagement was present.   When the selector lever was […]