Diagnosing Transmission Problems

More Technical

Diagnosing Ford 10R60, 10R80 and 10R140 series speed sensor issues

Ford 10-speed 10R series transmissions utilize four two-wire, Hall-effect sensors — TSS, ISSA2, ISSAB and OSS — for providing speed signals to PCM or TCM. They are supplied nine volts by a PCM or TCM and assist in the control of clutch apply/release timing that is used in determining shift quality, including TCC. Here are

Jatco JF613E transmission quick reference material

For those working on the Jatco JR613E transmission, a widespread transmission with plenty of applications, the following should be a helpful guide. Domestic and international applications for the JF613E (also known as the RE6F01A, F6AJA / W6AJA, AJO) are as follows: Auto                                        Model                          Year                 Engine                             MITSUBISHI                        LANCER                    08–                 L4 1.8L 2.0L                          

Easy TH400, 4L80-E reverse servo setup: Craft your own tool

While not as sensitive as some shifting bands, the Reverse band adjustment on a TH400 or 4L80-E transmission is critical, and failure to get it right has tripped up even the best builders. There is nothing worse than getting the transmission installed, putting it in Reverse and then not going anywhere or having no engine

Spotting different 68RFE designs through the years to avoid issues

The Chrysler 68RFE has had several changes through the years. Its four-speed predecessor began with a noisy solenoid pack identified by a black colored pass-through case connector (seen in Figure 1).  In 2004, they changed to a quieter design assembly identified by a white pass-through connector (Figure 2).  This is used in all 45RFE and

Shift Pointers: Failures caused by incorrect tire sizes

For years ATSG has produced a wide range of issues related to improper tire sizes on vehicles. Even under-inflated tires have been known to cause issues. Problems such as premature failure with an active 4WD transfer case will occur with incorrect tire sizes. Additional issues include the following: As a result of some of these

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Understanding lube flow control valves in Toyota/Lexus UA/UB80 transmissions

The Toyota/Lexus UA80 and UB80 transmissions first came out in 2017 in Highlanders and Siennas. The UA80 is used in V6 applications, and the UB80 is paired with four-cylinder versions. They have been called Toyota New Global Architecture type transmissions, and alternately referred to as the “Direct Shift 8AT” eight-speed automatic transmission. This transmission was

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How reading through service bulletins can turn a technician into the customer’s hero

Over the last 28 years of being a technician, I have developed the habit of checking for and reading technical service bulletins at the forefront of the diagnostic process, especially when an unfamiliar vehicle exhibiting blatant or straightforward concerns comes into the shop. I have found many valuable nuggets of information while reading over these

Sometimes, you should sweat the small stuff

It’s a common phrase: There may have been a time when you worried about something, and someone who knew what you are going through said, “Hey, don’t sweat the small stuff.” Sometimes, this may be good advice. But other times, it may be wise to handle the small stuff before it becomes bigger “stuff.”  Fretting

Shift Pointers: Focused DTCs

On occasions when a vehicle’s computer system detects an error, it can set an array of diagnostic trouble codes. The variety and quantity of them require the ability to diagnose diagnostic codes, so it’s nice when codes set that point directly to the problem.  One interesting scenario that just recently came to us on the

Manual clutch repair and diagnostics

Manual gearboxes are relatively trouble-free and long-lived, provided that they are not abused too severely. The clutch, however, is a wear component. With every shift, the clutch must be disengaged and engaged. Stop-and-go driving in heavy traffic is especially hard on a clutch because the driver is always riding the clutch pedal. After millions of

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Looking deeper: Telling apart electrical issues and parts issues

We see such a variety of transmission problems these days, and all the electronics involved today certainly have added a whole new crop of potential issues. Even though a significant part of our diagnostic process is geared towards electrical issues, there are still times when the problem is simple and not related to electronics at

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Manual transmissions in 2023: Some are still sticking with it

Over the past 25 years, a combination of driver preference and fuel economy requirements have resulted in a marked decrease in the number of vehicles in the U.S. fleet that come equipped with a manual transmission. One can wax nostalgic for the “car guy” discussions from 40 or 50 years ago that included terms like