PROPEL TRANSMISSION
SUBSECTION 9B
Figure 9B-4 Relief Valves
INSPECT THE SHUTTLE VALVE Remove the two hex plugs
Figure 9B-6. Charge Pump Removal
and the shuttle valve parts Inspect for broken or damaged
parts and proper orientation (see Figure 9B-5) Washers
must go between the spool and springs. Inspect to see if the
spool moves smoothly in its bore.
NOTE
The spool and manifold are matched and cannot be
replaced separately.
INSPECT THE CHARGE CHECK VALVES
Protect the exposed cavities into the pump
from foreign material.
Figure 9B-7. Check Valve Interchange
INSPECT THE PUMP CHARGE RELIEF VALVE. If the charge
pressure is low (below 190 psi) in neutral only (okay in for-
ward and reverse), the charge relief valve located in the
charge pump should be inspected. Remove the hex plug and
relief valve parts (see Figure 9B-8). Inspect for foreign ma-
terial holding the poppet open, and for galling or wear on the
Figure 9B-5. Shuttle Valve
poppet and seat in the charge pump.
The charge check valves are located in the pump end cap,
under the charge pump. Remove the charge pump as de-
scribed later in this subsection (see Figure 9B-6). Remove
both charge check valves and keep them in the same rela-
tion to the end cap.
Inspect the check valve for spring loading by pushing
against the internal ball. A slight resistance should be felt
as the ball is pushed off its seat. The internal spring should
return the ball to its seat when force is removed. Check for
any foreign material inside the valve.
When the problem occurs in one direction only, inter-
change the check valves and see if the problem changes to
the other direction (see Figure 9B-7). If so, one check valve
is malfunctioning and should be replaced.
Figure 9B-8 Pump Charge Relief Valve
9B-5