Powertrax RING AND PINION SET - Manual (Page 2)

INSTALLATION INSTRUCTIONS continued...
10. Each ring and pinion is pre-run and marked on the
pinion face with its proper depth setting called the
“Checking Distance”. This dimension is from the face
of the pinion to the axle center-line. A setting tool
must be used to measure the checking distance. Pin-
ion depth is adjusted by adding or subtracting shim
distance. Stay +/- .002” of the pinion dimension (see
Illustrations ‘A’ and ‘B’).
11. Once pinion depth is achieved using a new crush
collar or preload shim pack (Dana®), set pinion bear-
ing preload to 15 inch-pounds rotating torque with
used bearings, and 25 inch-pounds with new bear-
ings. Once preload is set, install the seal and Loctite®
pinion nut.
12. Once the pinion gear is installed, position ring
gear and carrier into housing to check backlash. Each
ring gear and pinion is developed to run at .007” to
.009” backlash for street gear sets.
13. Adjustments for backlash are done by spanner
rings in the housing or shim packs behind the carrier
bearing cups (GM® or Dana®). Always be sure carrier
bearings are pre-loaded. The carrier should not fall
out of the housing, but should have to be “tapped”
in during final installation. Replace bearing caps and
torque to factory specifications.
14. You are now ready to verify the tooth contact
pattern. A gear marking compound should be used.
Paint gear teeth with compound in several spots and
rotate ring gear several revolutions. A tooth contact
pattern will appear and should be similar to the pat-
tern shown in Illustration ‘C’. If the pattern is not in
the approximate position shown, reset pinion depth
and backlash to correct pattern. Pinion shims usually
must be moved in .003” increments to notice a pat-
tern change. If a pattern is heavy toe, subtract shims
(see Illustration ‘D’). If a pattern is heavy heel, add
shims (see Illustration ‘E’).
NOTE: REVERSE THIS PROCEDURE FOR 8” AND 9”
FORD®.
15. Fill the case with the required amount of FRESH
EPW80-90 gear lube or Richmond 75W-140 synthetic
oil. (DO NOT USE “USED” gear lube – no matter how
low the mileage and time on the oil). Maintain the
proper level after the road test as this may change
fluid level. Add as necessary. Proper maintenance
is a must to ensure your safety, as well as protect the
working life of your gear set.
16. Make sure oil vent is not blocked in rear end
housing.
SPECIAL NOTE: IN EXTREME CONDITIONS WE
STRONGLY RECOMMEND A NEW DIFFERENTIAL COV-
ER THAT HAS AN EXTENDED OIL CAPACITY FOR NON-
REMOVEABLE CARRIER-TYPE REAR ENDS.
FINAL RESULTS
Properly maintained and assembled ring and pinion
gears should result in safe and satisfactory perfor-
mance. If improperly maintained and/or assembled,
you could experience premature failure. Be sure the
application of your gear set is the correct one
BREAK-IN PERIOD REQUIRED !
-LIGHT DRIVING FOR A PERIOD OF 500 MILES
AND
NOT AT A CONSTANT ROAD SPEED (50-60
MPH) FOR ANY RATIOS LOWER THAN 3.73.
-NO TOWING FOR EXTENDED PERIODS