|
CV
JOINTS
Tool and Material Checklist:
-
Screwdrivers
-
Pusher tool
-
Metal shears
-
Vise
-
Breaker bar or torque wrench
-
Snap ring or duckbill pliers
-
Drift
-
Assorted wrenches
-
CV joint grease
-
Wire
-
PUS,,
-
Evaporating spray solvent
-
Tape
Constant velocity, or CV, joints enable drive
power to be transmitted through sharp angles.
They must tolerate 200 vertical suspension movement and 50° side-to-side movement for steering.
Front-wheel-drive cars have two drive shafts, or
half shafts. There are CV joints at both ends of the
half shafts. The CV joint that attaches one end of
each half shaft to the differential portion of the
transaxle is called an inboard. inboard, or plunge,
CV joints must accommodate the in-and-out
movement of the half shafts as the suspension operates. The CV joint at the other end of the half
shaft Is called an outboard, or fixed, joint.
Outboard CV joints are almost always the Rzeppa type; there are several types of Inboard joints,
including the tripod and the Rzeppa with a plunging outer race. Nevertheless, every kind of CV joint
uses a boot and is serviced in a similar fashion.
THE IMPORTANCE
OF THE BOOT
Neoprene or polyurethane boots are used to
protect CV joints. The most frequent cause of CV
joint failure is a bad boot. Thus, the boot should be
replaced at the first sign of damage or deterioration to prevent damage to the CV joint. The cost of
replacing a boot is inexpensive when compared to
the price of a new CV joint.
BOOT INSPECTION
At the very least, boots should be checked during every oil change or at approximately
3,000mile intervals. it is especially important that this be
done just before winter, once during the winter,
and again in the spring.
An inspection is easier with the car on a lift, but
it can be done in your driveway as follows:
1. Turn the steering wheel all the way to the left
or right to spread out the folds of the boots.
2. Look under the front bumper and check for
grease on the boots.
3. Check the boots for cracks, splits, tears, and
holes. If any boot appears rotted, replace it.
4. Move the car several times approximately 1'
to check all the way around the boots.
5. Squeeze-test the boots. If any air escapes, replacement is required.
6. Check the clamps for tightness. Hold a
screwdriver to the band and push; the clamp
should not wiggle. If it does, go to the next step.
7. Cut off the clamp with metal shears. (Be very
careful not to slice the boot.)
8. Slide the boot back and scoop out a little of
the grease.
9. if the grease appears milky, it has been contaminated with water. Rub it between your fingers.
If it is gritty, dirt has entered the joint.
10. If the grease is contaminated with water
and/or dirt, the CV joint should be examined and a
new boot installed.
REMOVING THE HALF SHAFT
To replace a boot or examine a CV joint, the half
shaft must be removed. Once this is done, examine
both joints and install two new boots. Always read
the specific instructions for your particular vehicle;
check the service manual or the instructions provided with the replacement boots. Here is the basic
procedure for removing a half shaft from a front- wheel-drive car:
Disconnecting the
Outboard End
1. With all four wheels on the ground and the
brakes applied, loosen the hub nut. Do not use an
impact wrench.
2. Raise the car and support it under the side
rails or chassis cross member.
3. Remove the hub nut, washer, and wheel.
4. If the shaft of the inboard joint is pressed into
the transaxle, disconnect the outboard joint from
the steering knuckle and then disconnect the inboard joint.
5. If the shaft of the inboard joint is bolted to an
output flange at the transaxle, unbolt the inboard
joint and then disconnect the outboard joint from
the steering knuckle.
6. Disconnect the brake hose clip and remove
the brake caliper from its mount. Support the caliper with a piece of wire-do not let it hang free.
7. Mark the relative position of the steering
knuckle cam bolts with respect to the strut. This
will help align the camber selling when the steering knuckle and strut are attached.
NOTE: If the bolts are not aligned properly,
wheel alignment might be necessary.
8. Separate the steering knuckle from the strut.
9. Push out the knuckle while pulling the half
shaft back through the wheel hub.
10. If this does not separate the two, try prying
them apart, but do not pound on the end of the
shaft with a hammer. This can damage the wheel
bearings, the splines in the hub, the CV joint,
and/or the differential gears. If the pads cannot be
pried apart, use a hub puller to separate them.
11. Once the outboard end of the shaft is free,
support it with a wire until the other end of the
shaft can be disconnected. Do not allow the shaft
to hang-it could damage the Inboard joint.
Disconnecting the inboard Joint
Separate the inboard joint from the transaxle
either by unbolting the inboard joint or pulling it
out. When pulling it out, hold on to the outboard
joint with one hand and the inboard joint with the
other. Do not pull on the shaft because the joint
might pull apart. It might be necessary to use a
large screwdriver, pry bar, or slide hammer between the inboard joint and the transaxle to pull
the shaft.
Be sure to consult the service manual for specific instructions. In some cars with automatic
transaxles, the speedometer cable drive must be removed before the inboard joint can be pulled.
Other cars require that the oil first be drained from
the transaxle.
CV JOINT REMOVAL
You are now ready to remove the CV joint. Use
the following procedure, choosing that which applies to your vehicle.
Outboard Joint
This procedure applies to Rzeppa joints only.
1. Place the shaft in a vise that has a soft-jaw
adapter. If this type of vise is not available, slide
rubber or wood strips between the vise jaws and
shaft. Be careful not to over-tighten the vise.
2. Make a mark on the shaft where the outer
boot ends, then cut away the old boot and clamps.
3. Wipe the grease from the face of the joint.
4. Note whether or not the joint is secured by a
snap ring. If it is, there will be a recessed pocket in
the face of the inner race, and the snap ring tangs
must be held open with snap ring or duckbill pliers
during step 5. If the joint Is secured by a small circlip on the end of the shaft, tap the
circlip off the
shaft to remove this type of joint.
5. Strike the outboard housing with a soft
hammer to drive the joint off the shaft. If the joint
does not come off, use a brass drift against the
face of the inner race to drive it off.
6. Clean the splines on the end of the shaft. Apply a light coat of grease before reassembly.
Inboard Joint (Tripod Type)
1. Cut away the boot and clamps. In some
cases, a boot retaining ring is used instead of a
clamp. Use a brass drift to drive it away from the
outer housing.
2. If the joint is to be reused, be sure to mark the
relative position of the rollers with respect to the
tracks they go into. Reassembling the joint in the
wrong track could result in looseness, binding,
and/or premature joint failure.
3. Remove the outer housing from the tripod. In
some instances, this might require slightly deforming the tripod retaining rings or tabs with pliers or
a screwdriver.
4. Wipe the grease away from the end of the half.
5. If a snap ring Is visible at the end of the shaft,
remove and discard it. Otherwise, move the spacer
ring back on the shaft and slide the tripod assembly away from the end of the shaft so that the
circlip is exposed. Remove the circlip and discard it.
6. On some cars, the roller bearings are not held
on the tripod by snap rings. If the joint is to be
reused, wrap tape around the tripod to prevent the
rollers from falling off.
7. Remove the tripod from the shaft, using a
hammer and drift to tap against the base of the
tripod. Do not pound on the roller bearings.
8. Clean the splines of the shaft. Apply a light
coat of grease before reassembly.
Inboard Joint (Rzeppa
Cross-Groove)
1. Cut away the boot clamp.
2. Use a hammer and drift to drive the boot and
cap assembly back and away from the CV joint.
3. Wipe the grease away from the half shaft.
4. Use snap ring pliers to remove the snap ring
from the end of the shaft. Discard the snap ring.
5. Use an arbor press to remove the inboard
joint from the shaft, or use a hammer and drift to
tap against the inner race.
6. Slide the dished washer (if used) and boot
and cap assembly off the shaft.
7. Clean the splines on the end of the shaft. Apply a thin coat of grease prior to reassembly.
CV JOINT INSPECTION
1. Clean the joint by soaking it in an evaporating
spray solvent such as the type made for brakes. Do
not use gasoline.
2. Inspect the condition of the internal components. For ball-type joints, follow step 3; for tripod
joints, follow step 4.
3. Tilt the inner race to one side to expose each
ball. Joint replacement is required if any of the following exist: severe pitting; galling; play between
the ball and its cage window; cracking or other
damage to the cage; or pitting, galling, or chips in
the raceways.
4. Examine the fit between the rollers and housing. Joint replacement is required if any of the
following exist: excessive free play; roughness on
either the roller or track surfaces; or damage to the
bearings or trunnions.
CV JOINT INSTALLATION
To install the CV joint, use the following procedures. Again, choose the one that applies to your
vehicle.
Outboard Joint
1. If a circlip on the end of the half shaft is used
to retain the joint, always install a new one.
2. Tape the shaft splines to avoid damaging the
new rubber boot.
3. Slide the small boot clamp and boot onto the
shaft.
4. Remove the tape from the splines.
5. Fill the cavity behind the balls, the splined
hole in the joint inner race, the ball tracks, and the
outer face flush with grease. Put any leftover
grease into the boot.
NOTE: Use the grease provided in the CV joint
kit or boot kit. Do not use a substitute or mix the
approved grease with other lubricants.
6. Slide the joint onto the shaft splines. Push the
joint onto the drive shaft until it clicks into place.
Pull on the joint to make sure it is secure.
7. Bring the edge of the boot to the mark made
earlier on the shaft.
8. Pull the boot over the joint, making sure It is
not dimpled or collapsed.
9. Slide the clamps into place and tighten.
Inboard Joint
1. Slide the small boot clamp and boot onto the
half shaft. For tripod-type joints, follow step 2; for
Rzeppa cross-groove joints. follow step 3.
2. Align the splines of the tripod with the shaft
and gently tap it onto the shaft with a soft hammer.
3. Install the dished washer (if used) with the
concave side facing the near end of the shaft.
Align the splines on the joint with the shaft. Gently
tap the joint onto the shaft with a soft hammer.
4. Install a new snap ring on the end of the shaft
to lock the CV joint or tripod in place.
5. Completely pack the CV joint (or the tripod
rollers and outer housing) with grease. Any grease
remaining from the CV joint kit or boot kit should
be put in the boot. Do not use substitute grease.
6. On the tripod-type joint, slide the outer housing onto the tripod.
7. Pull the boot over the joint. Make sure the
boot is not dimpled or collapsed.
8. Slide the clamps into place and tighten.
INSTALLATION OF
THE HALF SHAFT
Remember to support the half shaft with wire
during installation so that it does not hang. Also,
replace and torque all fasteners, including the hub
nut, to the manufacturer's specifications. If the
knuckle was disconnected from the strut, a check
of the front wheel camber might be necessary.
|