Another Day at the Orifice
Modifying orifice size in valve body separator plates has been practiced as long as automatic transmissions have been in existence. From performance upgrades to attempting to fix problems caused by valve-body wear, opening up orifices can provide positive effects – but can just as easily cause unforeseen problems. To avoid unwanted results, it is necessary to know when to drill, what size to drill to and when not to drill.
All Over the Map
Burnt 3-4 clutch packs are notoriously common in the GM 4L60/E family of transmissions. Tech hotlines and internet bulletin boards are often jammed-up with people pleading for help with this 3-4 roasting. Some technicians get frustrated and throw multiple Hail Mary replacement parts at the transmission when facing this issue. But it doesn’t have to be an exercise in frustration; burnt 3-4 clutches can be transformed from a dreaded problem into a routine moneymaker.
Even Odds
In the world of vehicle repair, independent shops also are competing at a disadvantage. In this case, the odds are stacked not in favor of a blackjack dealer, but rather a new-car dealer. Franchised new-car dealerships have ready access to proprietary technical information, equipment and capabilities that are not available to the aftermarket. However, unlike casino games, fixing cars is much more important than a bit of entertainment; it is the lifeblood for many thousands of people, and affects millions of drivers.
Adapt & Overcome
The TCM is responsible for monitoring and controlling transmission operation through the use of various sensors, solenoids, relays, switches, etc. Computer management provides benefits such as precise shift timing, fault detection and increased fuel economy. But a more remarkable feature is the TCM’s ability to compensate for changes in engine performance, vehicle load, driving patterns and physical wear inside the transmission by adapting its control tactics.
GM Compensator-Feed System
There are a growing number of transmissions on the road that incorporate a hydraulic control feature many technicians are unfamiliar with, though they may have noticed the involved components during many builds. Variations of this system can be found in GM and ZF six-speeds, many Aisin AW units and some Ford models. If you haven’t already, it’s an easy bet you will encounter malfunctions related to it sooner or later.
