Pinion seal on a 99 tahoe

[jamesbellew]

How hard is it to place this seal?

[GaryL]

Here's what I found:

PINION FLANGE & OIL SEAL

NOTE: If replacing pinion and ring gear, discard original pinion flange after removal. Replacement pinion, ring gear and
pinion flange are balanced as an assembly.

Removal
1) Raise and support vehicle. Remove rear wheels and brake
drums. Mark drive shaft, axle shafts, pinion flanges and output shafts for reassembly. Unbolt drive shaft, and wire aside. Using tape, secure "U" joint bearing caps. Using an INCH-lb. torque wrench, rotate pinion several revolutions. Stop and start rotation several times. Note and
record pinion bearing preload.

2) Match mark pinion-to-nut and nut-to-pinion flange for
reassembly purposes. Count and record number of exposed threads on pinion.

3) Hold pinion flange with Pinion Flange Holder (J-8614-01).
See Fig. 4. Remove nut and washer. Install Pinion Flange Remover (J-8614-1, J-8614-2 or J-8614-3) through pinion flange holder. Pry pinion seal from housing.

Installation
1) Thoroughly clean contact area. Inspect pinion flange oil
seal surface and drive splines. Replace pinion flange if damaged. Lubricate inside diameter of seal. Place pinion seal in housing bore.

2) Using Seal Installer (J-23911 for 7 5/8", J-22836 for 8
1/2" and 8 5/8", or J-22388 for 9 1/2"), install pinion seal. Apply a coat of high-temperature lubricant to pinion seal lip.
CAUTION: DO NOT hammer flange onto pinion shaft to install. Ring gear and pinion will be damaged.

3) Align pinion flange marks with marks on pinion. Install
pinion flange. Install washer and NEW nut to pinion. Tighten nut snug,taking note of scribe marks and number of exposed threads. Measure pinion preload. Using pinion flange holder and remover, tighten nut in small increments. Rotate flange after each increment. Tighten pinion nut until original preload.

4) On all models, except "S" and "T" series trucks, if
original preload was less than 3 INCH lbs. (.3 N.m), set preload to 3-5 INCH lbs. (.3-.6 N.m). On "S" and "T" series trucks, set preload to 3-5 INCH lbs. (.3-.6 N.m) greater than original recorded specification. On all models, if rotating torque has been exceeded, a new collapsible spacer will have to be installed. Install drive shaft. Add lubricant as needed.