TM 9-2320-266-34
(5) Stop the engine and carefully remove the tool.
ameter (peripheral) weld.
(6) If the upper surface of the test probe is dry, there
(2) The front pump hub weld.
is no converter leak. A path of fluid across the probe indi-
cates a converter leak. Oil leaking under the probe is coming
{3) The crankshaft pilot weld.
from the transmission converter area (figure 4-14).
(4) Fluid leakage from the converter drain plug. These
leaks appear at the outside diameter of the converter on the
engine side.
Figure 4-15. Torque Converter Cross Section.
d. Air Pressure Test of Transmission. The equipment
needed for the test is shown in figures 4-16, 4-17, and 4-18.
After removing the torque converter, prepare the transmis-
Legend for Figure 4-14:
4. Case or front pump housing
1. Converter hub seal
sion for the pressure test as follows:
2. "0" ring seal
5. Vent
3. Front pump-to-case bolts
6. Kickdown lever shaft access plug
Figure 4-14. Transmission Converter Area.
(7) Drain the fluid from the transmission and con-
verter. Reinstall the converter drain plug and the oil pan
(with a new pan gasket). Remove the transmission and the
torque converter assembly from the truck and install it in a
test stand for further investigation.
(8) Possible sources of transmission converter area
fluid leakage shown in figure 4-14 are:
(a) Converter hub seal.
1. The seal lip is cut. Check the converter
hub finish.
Figure 4-16. Converter Hub Seal Cup.
2. The bushing is moved and/or worn.
3. The oil return hold in the front pump hous-
ing is plugged or omitted.
4. A seal is worn out.
(b) Fluid leakage at the outside diameter from
the pump housing "O" ring seal.
(c) Fluid leakage at the front pump-to-case bolts.
(d) Fluid leakage due to case or front pump hous-
ing porosity.
(e) Fluid leakage from the vent.
(f) Kickdown lever shaft access plug.
sources of converter leakage are:
Figure 4-17. Hub SW Cup Retaining Strap.
4-16
