Converter Clutch Control Part 2
An understanding of hydraulics is essential for properly diagnosing and repairing transmission problems. This is part two of a two-part article on how an understanding of converter clutch control aids in transmission diagnostics. Part one described fluid path and torque converter terminology. Part two examines the source and factors affecting the control of the clutch.
Hydraulics Fundamentals: Converter Clutch Control Part 1
An understanding of hydraulics is essential for properly diagnosing and repairing transmission problems. This is part one of a two-part article on how an understanding of converter clutch control aids in transmission diagnostics. Part one describes fluid path and torque converter terminology. Part two addresses the valves that control those circuits and the clutch control.
CVT Success: In-Vehicle Isolation of Common Problems
All transmission models have unique problems that are common to that model; Jatco CVT units are no exception. Technicians are facing an uphill battle when it comes to diagnosing and repairing CVTs if they don’t have the right information on hand. Knowing what the common issues are and understanding the options available to isolate and fix problems are the keys to CVT success.
Six Ways from Sunday: Diagnosing ZF6 & Ford 6R60/80 TC-Related Drivability Concerns
Recently, TV picture troubles caused us to summon a repair technician to our home. The technician (we’ll call him Tech No. 1) snapped on his tool belt and started disassembling components as soon as he arrived. He checked over the satellite dish, then he continued the assault on the house by removing rows of ceiling tile for an in-depth inspection. After hand-checking all the connections, an hour into his service call, he condemned the satellite receiver. A couple days later the suspect receiver was replaced, but the intermittent screen-digitization problem remained.
Valve-Body Qualification
Although traditional visual indicators such as the wiggle, deflection, flashlight and visual bore-wear inspection are still useful, we’ll start this review with pressure and vacuum before finishing up with valve-body test stands.
Aisin AW Linear Solenoids
In this article, the AW 55-50/51 five-speed (also known as AF 23/33) will be referred to as the AW 5.
5L40-E/5L50-E
As valves and bores begin to wear and allow leakage, the easiest path for the leak is to exhaust. Two things happen as a result of this wear-induced exhaust leak. First, the leak allows a pressure drop, which is loss of control pressure. Valves or components no longer move, apply or respond as intended. Second, the amount of exhausted fluid and, therefore, the amount of air entering the sump are increased. The amount of aeration can easily surpass the sump’s ability to dissipate the air before the pump picks it up. The minimal sump capacity of the 5L40-E makes it especially vulnerable to this problem.
AW55-50SN
By the time they arrive, they are well-seasoned units, although not necessarily what you would consider high-mileage. Although these automakers use the same transmission, there will be variations in the shafts, drums, converters, valve bodies and TCM calibration. The 2-3/3-2 shift issues are common, regardless of brand, and may be accompanied by codes P0780/785 or P0745.
Detailing not just for Car Bodies
Vehicle restoration is a time-consuming process. Some projects remain scattered about the garage much longer than planned or appreciated. The definition and effort involved with detailing vary with the type of vehicle. An off-road Bronco probably gets a last set of decals, whereas the vintage collector gets paint and buffing.
Audi A8 Quattro
If you have ever driven an Audi A8 or any other high-end car using a ZF 5HP19 or 5HP24 transmission, you know these units are pretty smooth shifting and lockup is almost undetectable. This particular Audi came in with a customer complaint of a clunk or bump when the vehicle slowed. Initially, the car was diagnosed, and the unit was removed and rebuilt.
Adapting to the AW55-50SN Valve Body
Some things are less intimidating if you’re not the first to do it. That statement applies to both crossing a frozen lake and working on a problematic AW55-50SN. On the lake, heavy snow cover can prevent you from telling whether the ice is sufficient for support, and what you can’t see may end in a sink-or-swim experience. On the 55-50SN valve body, a clean core does not mean the valve body is functioning correctly.
4R100: Repeated Converter Failure
In this lesson we will hear of a 4R100 in a 2000 7.3-liter diesel with repeated (four times) converter failures.
