Seal Ring Service
Seal rings are critical to proper transmission and
transaxle operation, since they seal in hydraulic fluid going
from the valve body to the bands and clutch packs. Seal
rings can be made of metal or Teflon. They should always
be replaced during a rebuild.
After removing the old seal rings, check the ring
grooves, Figure 17-37. They must not be worn. Look for
nicks or ridges on the groove walls that could prevent the
new ring from seating properly, allowing leaks. Groove
width can usually be checked with the new ring and a
feeler gauge, Figure 17-38.
Check the bore surfaces that the seal rings ride
against, as well. The bore surfaces must be round and
smooth, with no ridges or signs of wear. Place the replace-
ment ring squarely in the bore to see that it conforms to the
414 Automatic Transmissions and Transaxles
Figure 17-34. The kit shown here is used to repair a chronic
bushing failure problem on a common truck transmission. It also
corrects torque converter slippage and resultant computer con-
trol system problems. The replacement bushing is an improved
type that resists wear. Instructions furnished with the kit explain
how to drill and enlarge lube holes to further increase bushing life,
and how to install an improved converter drainback valve.(Superior)
Sleeve
Valve
Figure 17-35. Exploded view of an oil pump–mounted valve
and its aluminum sleeve. The valve and sleeve should be care-
fully checked for sticking, scoring, or other damage. As with a
valve body, be sure that all pump-mounted valve components
are reinstalled in their original positions. (Sonnax)
Shiny edge
must face
in direction
of arrow
Pump
vanes
Pump
housing
Figure 17-36. The pump must be carefully reassembled to
provide proper pressures and long service. This vane pump is
mounted in the side valve body of a common transaxle. (Ford)
Note: Some pumps installed in the case
require that a special tool called an aligning
band be placed around the two halves of
the pump to ensure that they are properly aligned
before the bolts are tightened.