Make sure that you have the correct new seal. Its
outside and inside diameters must be the same as the
old seal. A seal part number is stamped on the outside
of the seal. This number and the seal manufacturers
name will assist you when ordering a new seal.
Before installing the new seal, coat the outer
diameter with a non-hardening sealer. Coat the inside
of the seal with lubricant that is the same grade that is in
the axle assembly. With the seal facing in the right
direction (sealing lip towards inside of the housing),
drive the seal squarely into place, using a seal-driving
tool. Be careful not to bend the metal seal housing or a
leak can result. Make sure the seal is fully seated.
REVIEW 3 QUESTIONS
What component prevents pressure from
building up inside the axle housing?
What type of axle only transmits torque from the
differential and carries no vehicle weight?
What two types of CV joints are used on
front-wheel drive vehicles?
Worn and damaged axle bearings produce what
type of sound(s)?
What tool is used to remove a housing mounted
Learning Objective: Explain the operation of a
transfer case. Explain basic service operations on a
Transfer cases are used in off-road vehicles to
divide engine torque between the front and rear driving
axles. The transfer case also allows the front driving
axle to be disengaged, which is necessary to prevent
undue drive line component wear during highway use.
Another purpose of the transfer case is to move the
drive shaft for the front driving axle off to the side so
that it can clear the engine. This arrangement is
necessary to allow adequate ground clearance and to
allow the body of the vehicle to remain at a practical
height. Figure 5-27 shows a typical drive line
arrangement with a transfer case.
CONVENTIONAL TRANSFER CASE
A conventional transfer case is constructed similar
to a transmission, in that it uses shift forks, splines,
gears, shims, bearings, and other components found in
manual and automatic transmissions. The transfer case
has an outer case made of either cast iron or aluminum
that is filled with a lubricant that cuts friction on all
moving parts. Seals hold the lubricant in the case and
prevent leakage from around the shafts and yokes.
Shims are used to set up the proper clearances between
the internal components and the case.
Figure 5-27.Typical drive line arrangement with a transfer case.