Diagnosing Transmission Problems
Looking for the cause of repeated 6T40 torque converter failure

The converter clutch was applied just enough to drag but not enough to kill the engine.

6T40 delayed engagements after overhaul

The problem lies in the compensator piston that a generation two clutch housing uses compared to the generation one housing.

GM 6T70/75 slips and delays in first

A 2015 Chevrolet Equinox equipped with the 3.6-liter engine and 6T75 transmission has complaints of a delayed engagement into drive and slips in first gear.

How to fix GM 6T70/Ford 6F50 rattling noise with transmission in gear

A rattling noise is coming from the transmission whenever the engine is running and the transmission is in gear.

The importance of the follow-up road test after transmission replacement

A 2002 Lexus RX300 equipped with a 3.0-liter V6 engine and U140F transmission was brought into our facility with a few concerns. The customer said that “it has a leak, a grinding noise when taking off from a stop, and it just doesn’t seem to shift right.” They went on to tell us that this

RR Tech Feature Oct
Tips and tricks for Chrysler switch valve plug testing

As technicians, we are often faced with build issues that can sometimes be frustrating at first. But with a little ingenuity, these frustrations can be turned around and made simple. In 1989, Dodge came out with the first fully hydraulic electronic-solenoid shifting transmission, the A604 (no shift valves), which later became the 41TE. Originally, there

GM 8L90 #7 Check-ball: The overheat that saved the day

Beginning in October of 2015, GM removed the #7 Check-ball from the solenoid valve control body in the 8L90 transmission (see Figure 1). This was done in conjunction with the elimination of the Lube Override Enable Valve from the upper valve body as shown in Figure 2. When this took place, the Lube Override Enable

Shift Pointers: Nissan’s no throttle response

Nissan vehicles using continuously variable transmissions (CVTs) are notorious for defaulting to a no throttle response when the vehicle is engaged into gear. There are several malfunctions that can cause this protective failsafe feature to be initiated. A brake switch (stop lamp switch) stuck on, a double-footed driver, blown or incorrect brake bulbs, and wheel

Jatco/Nissan JF011E critical wear areas and vacuum test locations

Sonnax has provided the following guide on critical wear areas and vacuum test locations for the Jatco/Nissan JF011E. Technicians working on these models should find this guide helpful. (Ed. Note: This is an extended version of the guide found in our September issue, with three additional pages).

ZF 6HP26: A torque calculation error

A 2008 Lincoln Navigator with a ZF 6HP26 transmission arrives at Holcomb’s Transmissions in limp. When checked for codes, a P1719 comes up for “Inaccurate Engine Torque Signal.” The TCM receives this over the CAN, causing it to initiate failsafe. The information Ford provides for this code is vague. The Action step provided is to

Dealing with the increasingly common pin-fit problem

I want to talk a little bit about a common diagnostic misstep or overlooked problem that is prevalent in the automotive repair industry and seems to be on the rise. Pin-fit or tension can deal us a fit sometimes (pun intended), especially if we do not have the proper tools to determine if this mode

Shift Pointers: Shift rod displacement in a luxury car

When owning a luxury vehicle, one cannot be faint-hearted when the time comes to pay a repair bill. Even if you bought a used luxury car at a very good price, this doesn’t change the price of new components required to make that repair. Such was the case with Kevin at Sampson Transmission. It began