Diagnosing Transmission Problems
Comparing the pumps on Ford 6F35 generation 1 and 2

The change For the 2013 model year, the Ford 6F35 transmission received a high-volume pump which increased the intake channel in the stator shaft support from 0.432” to 0.520”. The pump body intake channel was also increased to the same matching dimensions. The reason Higher pump volume was required to accommodate the 1.5-, 1.6- and

A 3D printing solution for 948TE offset pump access

The Chrysler 948TE has an offset pump mounted in a housing that is retained by round internal snap ring that must be squeezed to release the pump from the housing (seen in Figure 1). The difficulty in doing so: there is a double tension plate located at the bottom side of the pump (Figure 2).

6F35: A classic bolt intrusion

I remember the first time I took a phone call from a shop that had a GM 4L60-E with a complaint that it felt like it was bound up in both reverse and drive. I you got into the throttle a bit, it would move but with a terrible noise. After the Park Pawl was

An easier way to install the center support in GM transmissions

Whether you are working on a 6L45, 50, 80 or 90, installing the center support that houses the L/R and 2-6 Brake clutches into the case can at times be difficult. In the past, I would grab the inside of the assembly with my fingertips on the friction teeth of the 2-6 clutch pack. I’d

BMW dual-clutch transmission diagnostics

The phrase “dual-clutch transmission,” or DCT, can strike terror in the heart of some technicians. You will probably never deal with the internals of a DCT transmission like the gears, synchronizers and shafts. You will instead have to repair the external components that control the clutches and cool the fluid. But, understanding how the gears

An accidental solution: When an issue resolves itself, but you don’t know why

Today I found myself working on a 2008 Chevy Silverado with a 4L60E transmission that wasn’t shifting correctly and whose speedometer was jumping around. After a short drive I was able to confirm the customer’s concern that the transmission had an erratic shift. I have seen faulty alternators that cause erratic speedometers, so I did

Troubleshooting Ford 6R80, 6R140 2-3 shift quality issues

We are all too familiar by now with the numerous band numbers on Ford 6R80 and 6R140 transmissions. We know that — unless you are programming in a new calibration code — it is best to replace a solenoid with the exact same band number as what was taken out of that position on the

Japanese CVT no-move conditions: Failsafe or defective TCM?

The Japanese Automatic Transmission Company produces a continuously variable transmission (CVT) known as the JF016/17E, which has been fitted behind 2.0L to 3.5L engines worldwide. Here in the United States, there is a light version called the CVT-8LT for 4 cylinder applications (JF016E) and a heavier version called the CVT-8HT for V-6 applications (JF017E). Nissan

Having a fit with a Honda Fit

A Honda Fit utilizing a GTAA continuously variable transmission will set a DTC after reaching about 30 miles per hour. When a scan tool is used to pull the code or codes set, a U0401-68 code appears in the scan tool with the explanation of it being a TCM failure. If a tech uses the

How to service Volkswagen, Audi dual clutch transmissions

You may have heard the term “DSG” or “DCT” being used when referring to Volkswagen/Audi transmissions. DSG, which stands for “direct shift gearbox,” is the marketing term used by VW/Audi for their dual-clutch transmission (DCT). In simple terms, this type of transmission is composed of two separate manual transmissions inside a single case, each one

Ford 6R80 & 6R140: Troubleshooting timing-related shift issues

As the old saying goes: “timing is truly everything.” Or is it? Either way, we know for sure that this is extremely true in the world of transmissions. Timing problems with clutch apply or with combined clutch apply and clutch release can create all kinds of complaints from flared shifts to harsh shifts to a

GM 10L80: A new kind of pump noise

How quickly time passes by. The GM 10L80/90 transmissions began production in 2017, meaning that we’re closing in on six years of this transmission being on the road. Many who work in the dealerships have become privy to the immediate failures that occur in this unit. And now, with some of these transmissions coming out