TCC Crowd Shudder & TCC Apply Shudder
CONDITION CAUSE AND CORRECTIONTCC APPLY TCC CROWD
SHUDDER SHUDDER
X X 1. An intermittent incorrect
signal from the vehicle speed sensor (V.S.S.). Dirt or grease on the reflective bar in the V.S.S. may be sending an incorrect or erratic signal so that the converter clutch engages early. Remove the V.S.S. and clean it.
X X 2. The auxiliary valve body cover
attaching bolts may be loose or the bolt threads/holes may be shallow. If the holes are shallow, the bolts will bottom out without torquing the cover down.
X 3. Some 1982 models were built
with either an exhaust hole or an orifice cup plug in the auxiliary valve body cover. The valve body cover was
CONDITION CAUSE AND CORRECTION
TCC APPLY TCC CROWD
SHUDDER SHUDDER
changed to a solid cover (no exhaust hole or orifice cup plug) in 1982. The service auxiliary valve body cover, part number 8643645, should be used on a11 models to prevent shudder. The service part does not have an orifice cup plug.
Figure 1:
X 4. There are two types of
auxiliary valve bodies in service. One has an orifice cup plug and the other does not (fig. 1). If the transmission being serviced has the auxiliary valve body with the orifice cup plug, particles of the auxiliary valve body cover gasket may have torn loose. This material may be sticking the torque converter clutch apply valve and/or plugging the converter release orifice in the control valve body spacer plate. If this is found, disassemble the auxiliary valve body and thoroughly clean. Also, be sure to remove any gasket particles in the valve body spacer plate converter release orifice hole and replace the auxiliary valve body cover gasket, part No. 8653947
X 5. Check the valves in the
auxiliary valve body for freeness. (They must move in and out of their bore without sticking.)
Figure 2:
Figure 3:
CONDITION CAUSE AND CORRECTION
TCC APPLY TCC CROWD
SHUDDER SHUDDER
X 6. For gas engine/transmissions,
the auxiliary valve body
converter clutch control
regulator spring may be weak
and require replacement with
the new spring, part no.
8637888. On February 20, 1984,
for U.S. built and March 5,
1984 (Julian date 065) for
Canada built THM 125C trans-
missions. Refer to chart 1 (see page 5) for
serial number breakpoints. The
new spring part number 8637888,
went into production and has a
stronger load. For explana-
tions of nameplates, refer to
fig. 2 (U.S.) and fig. 3
(Canada).
X X 7. Inspect the pump shaft to valve
body seal for cuts, damage, distortion.
X X 8. A new governor pressure switch
went into production for diesel models only, in late April, 1982. This change corrects the "Shudder" feel, by raising the converter clutch apply speed. In servicing Diesel model transmissions for this condition, refer to the following chart for proper model usage for 1982 models:
MODEL GOVERNOR SWITCH
PART NUMBER
OP,HU,HY,H6,HR, 8643369
HW 8637296
HS 8643368
CD,HI,HC 8643367
Figure 4:
Figure 5:
CONDITION CAUSE AND CORRECTION
TCC APPLY TCC CROWD
SHUDDER SHUDDER
X 9. Inspect the turbine shaft
Teflon seals and "O" ring seal for damage, cuts, distortion (see figure 4 for these parts). If the teflon seals require replacement, make sure they are installed and sized as shown in fig. 5.
Figure 6:
X 10. Inspect the turbine shaft seal
grooves. A step in the bottom corners of the seal groove will keep the seal from contacting the side wall of the groove and will prevent proper sealing (fig. 6). If this condition is found, replace the turbine shaft and seals.
Figure 7:
X 11. Check the case cover sleeve
converter feed oil hole for being out of alignment with the oil channel in the case cover (fig. 7).
X 12. Check the converter end play,
using tool J-29830A. The end
play specification is .5 mm
(.020"). Converters with end
play more than .5 mm (.020")
must be replaced.
X 13. The turbine shaft sleeve may be
leaking excessively. If all of the above items are O.K., replace this shaft