Diagnosing Transmission Problems
January 2003 Issue

Issue Summary:

Accumulator springs that have been installed incorrectly, or accumulator-piston shafts that are scored or worn and are interfering with accumulator-piston movement, can cause various shift-quality complaints.

On some 1996 and 1997 Ford Taurus and Sable models, the PCM may have been reprogrammed to eliminate TCC operation during normal driving conditions.

Stuck On, Stuck Off or Just Plain Stuck

With the introduction of OBD-II, a ton of additional codes became available (remember, we were always asking for more information). In some instances, these new codes were a great help because they did not just indicate a short or an open circuit but also pointed to parameters that were out of range, which included both mechanical and electrical problems.

Even Failsafe Is Subject to Change

Since then, technology has leaped forward at a vicious pace, not breaking for breath. And with this technological race among the “Big 3” manufacturers (U.S., Japan and Europe) comes the need for various computer strategies. Failsafe is one of those strategies that has experienced a change.

Two New Tremec Transmissions for the Ford Mustang

The TR3650 is manufactured by Tremec Corp., a state-of-the-art transmission manufacturer with facilities in the United States and Mexico. Tremec bought the standard-transmission line from BorgWarner Corp. and continues to manufacture the T5, T45, TR3550, TKO and T56 transmissions.

Transmission Orifices

It may seem obvious initially, but when you’re talking about transmission orifices, size does matter. What may be surprising, though, is how significant a difference in vehicle performance small changes in orifice diameters can make. This becomes important when you’re considering modifications to separator-plate holes (see Figure 1) or cup-plug orifices (see Figure 2) during a rebuild.

Another Fantastic Ford Fable

A 1997 Ford E 250 van equipped with a 4.2-liter engine and a 4R70W transmission comes into the shop with a complaint of falling out of fourth gear into third at highway speeds. In local traffic, however, the transmission acts like a C6 with a stuck governor; it remains in second gear as you come to a stop and “dunks” down into first gear.

December 2002 Issue

Issue Summary:

Before or after overhaul, Volkswagen/Audi vehicles equipped with the 01M transaxle may exhibit no forward engagement or a slipping condition on take-off in first gear.

Beginning at the start of production for 1999 models, all THM 4L80-E transmissions were built with a revised manual-2nd band that is wider than the previous design.

Beginning at the start of production for all 1999-model THM 4L80-E transmissions, the planetary pinions on both carriers were produced 10% thicker than in the previous models.

Some 1995-96 Buick Century and Oldsmobile Ciera vehicles equipped with the 3.1-liter engine and the THM 4T40-E transaxle may exhibit a condition of third-gear starts and the air conditioner not working.

Some 1993-95 Cadillacs equipped with the THM 4T80-E transaxle may illuminate the Service Engine Soon lamp and store P080 as a current code. After you try to clear the code, it remains as a hard code.

Before and/or after rebuild of a THM 4T40-E, the vehicle illuminates the Check Engine lamp and stores code P1887 or P0742 in memory.

Is Your 4WD Explorer Neutralizing?

But inside the transfer case closest to the transmission is the transfer direct-clutch drum that the sealing rings just love to dig into. The severity of the wear determines the degree of the complaint; i.e., delayed engagements, slipping or no movement. Technicians often misdiagnose this problem by blaming the transmission for the problem when all along it has been in the transfer case.

November 2002 Issue

Issue Summary:

Ford introduced a new-design sun shell with tabs added to the center of the sun-shell slots in the 4R100 as a running change during the 2000 model year.

Starting with the 2000 model year on all AX4N transaxles and 2001 on all AX4S transaxles, Ford Motor Co. introduced a new-design pump bearing that includes an integrated seal.

When the bolts attaching the pump to the converter housing in the Ford A4LD, 4R55E, 5R55E, 5R55N or 5R55W are being tightened, the threads in one or more of the bolt holes may strip out, requiring repair using the Heli-Coil® method.

Beginning in the 2000 model year, as a running change to the A670 (31TH) and A604 (41TE), DaimlerChrysler introduced a new-design final-drive cross-shaft retainer and eliminated the retaining pin.

Load-Testing Solenoid Circuits

The last thing I want to do is put you to sleep with an article on performing electrical tests and Ohm’s Law. What I want to show here is something that I think is really exciting: load-testing solenoid circuits with an ammeter! Using an ammeter and a calculator can save time, LOTS OF TIME. How would you like to check the power distribution, ignition switch, external and internal wiring, solenoids, computer and computer grounds without putting the vehicle on a lift or even raising the hood?

Have You Seen My Drainback Ball?

When you unscrew the cooler-line fitting you notice that oil comes pouring freely. You now remove the cooler-line fitting, and lo and behold, there’s no #$^&*! checkball in the fitting.

Ford’s New M5R4: A Radical Design Change in Rear-Wheel-Drive Manual-Transmission Technology

In 2002 Ford introduced a new four-door model of the venerable Explorer and its sister, the Mercury Mountaineer. The manual-transmission option for the new four-door model is a five-speed fully synchronized unit designated the M5R4 or M5OD-R4. The M5R1 transmission we all know and love has been replaced by a radical new design built by Mazda. This unit bears no resemblance to the M5R1.