GRIP PRO INSTALLATION MANUAL
3
IMPORTANT APPLICATION NOTE
Before installing the ring gear
and pressing the bearings on to the
differential, the following two (2) items
need to be checked:
1. Ensure that your axle shaft
mates with the differential side gear.
Some models have different spline
counts depending on the year of
manufacture.
2. Check the differential flange
position (bearing shoulder to flange
face) to ensure that it is correct. You
may compare it to your old one. The
differential flange position depends
only on the gear ratio that you are
using. This flange position may
change at certain gear ratios. Some
aftermarket ring gear and pinion sets
specify the differential case “series”
that is required.
If you feel that you have the wrong
differential for your application,
contact your place of purchase and
make the necessary arrangements
to exchange the differential for the
correct one.
Once the differential has had bearings
and/or a ring gear installed, it can
no longer be considered new and
therefore cannot be exchanged for a
new one.
IMPORTANT LUBRICANT NOTE
The Powertrax® Grip Pro™ limited-
slip differential design uses helical
cut gears to transfer power to the
wheel with the most traction. Always
use an 80W-90 mineral/petroleum
based gear oil with at least a GL-5
rating. Synthetic oil and oils that
contain friction modifiers are NOT
recommended.
SPECIAL NOTES
All Powertrax® Grip Pro™ limited slip
carriers require a certain amount of
resistance with the ground to start
to the power transfer. A Grip Pro
differential will not transfer power if
the spinning wheel is off the ground.
In this situation a light application
of the brakes will generate enough
resistance to transfer the power to the
other wheel.
• Powertrax Grip Pro carriers can’t be
interchanged between the front and
rear differential.
• Chrysler® 8.75” Part# GT308730
applications require the use of sealed
non-adjustable wheel bearings and
the following carrier bearings:
LM104949 Cone
LM104912 Cup
• Dana® 35 Part# GT443527
applications might require the pinion
gear to be modified to clearance the
carrier case.
• Ford® 8” Part# GT108028
applications might require the pilot
bearing area to be modified to
clearance the carrier case. GT108028
requires the use of open type ring
gear bolts part# D8OZ4216B and the
following carrier bearings:
LM102949 Cone
LM102910 Cup
• Ford® 8.8” Part# GT108831 contains
2 axle spacers. The shorter spacer is
used for 1983-’86 models & the taller
spacer is used for 1987-’14 models.
