Below are some pictures of 12" torque converter parts from a 1997 ford
crown victoria police interceptor. All AODE and 4R70W transmissions use
similarly designed converters. A larger version of most of the pictures
below can be viewed by clicking on the image.
Here's the converter before it was cut open. The drain plug that's
visible on the top was "decontented" somewhere in the late 2001 - early
2002 model year depending on transmission model.
1/4" thick steel takes a large amount of effort to cut through. I
burned up one grinder and also went through a handful of abrasive
cutting wheels in the process of opening the converter.
Here's the converter with the top cover (impeller) removed. Visible are
the thrust washer, stator (reactor), and turbine.
Here's all the components inside the converter layed side by side.
Of note, the stator contains a one way clutch in the center that
rotates freely in one direction and locks up in the other direction.
And here's the same components flipped over.
Note that the angle, size, shape and number of the vanes (fins) inside
the converter all play an
important role in determining the "k-factor" or "stall speed" of the
unit. There are dozens of different torque converter models avaliable
for the AOD-E and 4R70W transmissions. But unless an aftermarket
converter is purchased, all units will be either 11.25" or 12" inch in
diameter.
Here the components are layed side by side in the order they were
removed from the converter.
From left to right: cover (flex plate studs/lockup clutch), pressure
plate, turbine, stator, thrust washer, impeller.
And the same view with the components flipped over
From left to right: cover (impeller), thrust washer, stator, turbine,
pressure plate, cover (flex plate studs/lockup clutch)
Here's the lockup system of the converter. Visible on the left is the
friction material. On the right is the pressure plate with it's
integrated torsional dampening springs. When this converter is actually
installed
on a transmission, the turbine shaft would pass through the center hole
of the pressure plate.
Converter slip can be varied anywhere from 0% to 100%. To obtain
controlled slip, transmission fluid is directed through the hollow
center portion of the turbine (forward clutch) shaft. Flow out the
turbine shaft lifts the pressure plate away from the cover which makes
the converter slip. When no fluid flows out of the turbine shaft, the
pressure plate is forced against the cover friction material by the
hydraulic forces against the other side of the turbine.
Of note, when components get worn, the slip rate that the powertrain
control module commands may not necessarily equate to the actual slip
rate of the converter. This can cause "shuddering" that sometimes
occurs in older high mileage crown vics. In this particular case, the
vehicle did not "shudder" at all. The friction material inside the
converter is in suprisingly good condition considering the vehicle had
close to 150k miles on it.
Also of note, the friction material is located on the case cover rather
than the pressure plate itself. This will cause a relatively small
amount
of slip ( <50 RPM ) even if 100% lockup were commanded in fourth
gear (overdrive).
The stamping of "LuK" on the pressure plate refers to the LuK
corporation. They have multiple internet addresses including: www.lukusa.com www.luk.com and www.luk.de
Here's a tape measure next to the converter outer shell depicting the
thickness of the outer cover.
Towards the bottom of the above picture, a glimpse of the back of the
torque converter drain plug is visible. When the drain plug was first
decontented from production vehicles, the converter cover was still
drilled for the plug and had a thin peice of sheetmetal spot welded
over the hole.