The SB or SSV – What’s The Difference?
Often, DTCs related to the solenoid switch valve (SSV) in any 41TE or 42LE transmission are misinterpreted as a problematic solenoid body (SB). This may be attributed to the use of the word “solenoid” in the code definition. Code 37 is the solenoid switch valve stuck in the TCC position, and 47 is the solenoid switch valve stuck in the L/R position. Either of these will place the transmission in “limp mode.” The solenoid switch valve is not in the solenoid body but in the valve body (see Figure 1).
A Case of Hide and Seek
One of the many automotive animals that technicians have to wrestle with is finding the definitions for the ever-increasing number of diagnostic codes. And then, of course, their definitions are being represented by a seemingly endless list of acronyms associated with that code. TCC, VSS and TPS are just a few recognizable acronyms in our industry today.
Replaced the What?
Sometimes a problem with a vehicle requires quite a bit of diagnostic head scratching, at the end of which you finally find what is causing the problem.
Isuzu NPR/GMC Tiltmaster
The Isuzu NPR Commercial Truck and GMC Forward Tiltmasters use an exhaust-brake system that assists in engine braking during downhill coasting while the trucks are carrying heavy loads. This system is used instead of the familiar Jacobs Vehicle System known as the “Jake Brake.” When the exhaust brake is activated, it restricts the flow of exhaust with a flapper valve in the exhaust pipe similar to that of a heat-riser assembly (see Figure 1). When the flapper valve closes, exhaust pressure increases, causing air intake to decrease. This increased backpressure and slower air intake reduce torque transfer to the geartrain, producing the desired on-demand engine braking needed during downhill coasting with a payload.
Orbiting Saturn
The problem here is in the assembly of the 1st-clutch drum. At first glance, all four of the piston-return-spring assemblies look identical (see Figure 1). Each caged assembly contains 16 springs and has an average overall height of 1.170 inches. The size and configuration of the spring cage allow for these assemblies to be interchanged among drums.
It’s a Tight Squeeze
I could only imagine the thoughts that ran through the minds of R&R men after they lifted the hood to view the Cadillac North Star/4T80-E combo for the first time. Perhaps it was something to the effect of, “Where is the transmission?”
Suceeding Through Diversity
From thousands of transmission technicians working in shops across the country, stories abound as to how each one found their way into the world of transmissions. With different ages, races and sexes occupying the trade, individuals come with varied levels of interest, education and ambition. As such, there come different levels of success in personal accomplishments and financial gain.
PCM Reprogramming
Many of us can agree that the older we grow, the more quickly time passes. Manufacturers would do well if they could invent a brake that could slow the clock of life. At times this clock of life seems to be similar to that of a brakeless 18-wheeler with its trailer fully loaded, barreling downhill, delivering the uncomfortable feeling of helplessness – you know, the feeling of recognizing that this out-of-control rig has got to come to a stop somehow.
