1994 JEEP CHEROKEE Service Repair Manual

(12) If equipped, remove the fog lamps (Fig. 10)
from the bumper rail.
(13) If necessary, remove the vacuum reservoir(s)
from the bumper rail.
(14) If necessary, remove the sill crossmember re-
inforcement brackets from the sillmembers.
ASSEMBLY/INSTALLATION
(1) If removed, install the sill crossmember rein-
forcement brackets on the sillmembers (Fig. 11).
Tighten bolts to 56 Nzm (41 ft-lbs) torque.
(2) If equipped, install the bumper support brack-
Fig. 4 Tow Hook & StrapÐXJ Vehicles
Fig. 5 Front Bumper Removal/Installation
Fig. 6 Bumper Support Bracket Removal/Installation
Fig. 7 Bumper Guard Removal/Installation
Fig. 8 Bumper End Cap Removal/Installation
13 - 4 FRAME AND BUMPERSJ

ets and bumper guards on the bumper rail. Tighten
hardware in the sequence indicated in Figure 7.
Tighten the locknuts with 20 Nzm (15 ft-lbs) torque.
Tighten bolts to 56 Nzm (41 ft-lbs) torque.(3) If not equipped with bumper guards, install the
bumper support brackets on the bumper rail. Tighten
bolts to 56 Nzm (41 ft-lbs) torque.
(4) If equipped with tow hooks, install the bolts
and nuts that attach them to the bumper support
brackets. Tighten nuts with 100 Nzm (74 ft-lbs)
torque.
(5) Install the bumper end caps on the bumper rail
(Fig. 8). Tighten nuts with 8 Nzm (72 in-lbs) torque.
(6) Install the license plate bracket on the bumper
rail. Tighten the nuts securely.
(7) If equipped, install the fog lamps on the
bumper rail. Tighten the nuts securely.
(8) If removed, install the vacuum reservoir(s) on
the bumper rail. Tighten the retaining screws and
bolts to 8 Nzm (72 in-lbs) torque.
(9) Position and support the bumper at the front of
the vehicle.
(10) Attach the bumper support brackets to the
right and left sillmembers and reinforcement brack-
ets. Tighten screws and bolts to 56 Nzm (41 ft-lbs)
torque.
(11) If equipped, install the Torx-head bolts and
locknuts that attach the tow hook straps to the un-
derbody sillmember. Tighten locknuts with 30 Nzm
(22 ft-lbs) torque.
Install the steering gear skid plate and screws
after the left tow hook strap has been installed.
(12) If equipped, connect the fog lamp wire harness
connectors.
(13) Connect the vacuum reservoir tube harness
connectors.
(14) Remove the bumper support.
FRONT TOW HOOKS
If a tow hook must be replaced or removed only for
service access, remove the nuts and bolts that attach
it to the bumper support bracket. When installing a
tow hook, tighten nuts with 100 Nzm (74 ft-lbs)
torque.
If a tow hook/bumper support bracket must be re-
placed, refer to the following removal and installa-
tion procedures.
REMOVAL
If equipped with a brush guard, refer to the
Brush Guard Removal within Group 23ÐBody
Components.
(1) If equipped, disconnect the fog lamp wire har-
ness connectors.
(2) Disconnect the vacuum reservoir tube harness
connectors.
(3) Support the bumper.
(4) Remove the bolts that attach the bumper sup-
port brackets to the right and left sillmembers.
(5) Remove the locknuts and Torx-head bolts that
attach the tow hook straps to the underbody sillmem-
ber.
Fig. 9 Bumper License Plate Bracket Removal/
Installation
Fig. 10 Fog Lamp
Fig. 11 Reinforcement Brackets
JFRAME AND BUMPERS 13 - 5

The retaining screws and the steering gear
skid plate must be removed before the left strap
can be removed from the sillmember.
(6) Detach the tow hook straps from the sillmem-
ber.
(7) Remove the support and the bumper from the
vehicle.
(8) Remove the nuts and bolts that attach the tow
hooks to the bumper support brackets.
(9) Remove the tow hook from the bumper support
bracket (Fig. 4).
(10) Remove the support bracket from the bumper
rail.
INSTALLATION
(1) If equipped, install the bumper guard and
bumper support bracket on the bumper rail. Tighten
the retaining hardware in the sequence indicated in
Figure 7. Tighten locknuts to 20 Nzm (15 ft-lbs)
torque. Tighten bolts to 56 Nzm (41 ft-lbs) torque.
(2) If not equipped with bumper guards, install the
bumper support bracket on the bumper rail. Tighten
bolts to 56 Nzm (41 ft-lbs) torque.
(3) Position the tow hook at the support bracket.
Install the bolts and nuts that attach tow hook to the
bumper support bracket. (Fig. 4). Tighten nuts to 100
Nzm (74 ft-lbs) torque.
(4) Position and support the bumper at the front of
the vehicle.
(5) Attach the bumper support brackets to the
right and left sillmembers and reinforcement brack-
ets. Tighten screws and bolts to 56 Nzm (41 ft-lbs)
torque.
(6) If equipped, install the Torx-head bolts and
locknuts that attach the tow hook straps to the un-
derbody sillmember. Tighten locknuts to 30 Nzm (22
ft-lbs) torque.
Install the steering gear skid plate and screws
after the left tow hook strap has been installed.
(7) If equipped, connect the fog lamp wire harness
connectors. Connect the vacuum reservoir tube har-
ness connectors.
(8) Remove the bumper support.
REAR BUMPER
REMOVAL
(1) For vehicles equipped with a trailer hitch, re-
move the hitch before removing the bumper. If nec-
essary, refer to the removal procedure within Group
23ÐBody Components.
(2) Raise and support the rear of the vehicle.
(3) Support the bumper.
(4) Remove the bolts that attach the bumper sup-
port brackets to the sill crossmember (Fig. 12).
(5) Remove the support and the rear bumper from
the vehicle.(6) Remove the bumper support brackets and
splash shield the bumper, if necessary (Fig. 13).
(7) Remove the bumper end caps (Fig. 14) and
bumper guards from the bumper (Fig. 15), if neces-
sary.
INSTALLATION
(1) As applicable, install the splash shield and
bumper support brackets, the bumper end caps and
the bumper guards.
(2) Tighten the bumper support bolts to 56 Nzm
(41 ft-lbs).
(3) Tighten the nuts in the sequence depicted in
Figure 14. Tighten the bumper end cap plate bolt
nuts to 22 Nzm (16 ft-lbs) torque. Tighten the lower
bolt nuts to 8 Nzm (6 ft-lbs) torque.
(4) If applicable, tighten the bumper guard bolts/
nuts to 56 Nzm (41 ft-lbs).
(5) Position and support the bumper with the
bracket holes aligned with the sill crossmember
Fig. 12 Rear Bumper Removal/InstallationÐXJ
Vehicles
Fig. 13 Bumper Bracket & Splash Shield Removal/
InstallationÐXJ Vehicles
13 - 6 FRAME AND BUMPERSJ

holes. Install the bracket-to-crossmember bolts.
Tighten the bolts to 42 Nzm (31 ft-lbs) torque.
(6) If removed, install the trailer hitch. If neces-
sary, refer to the installation procedure within Group
23ÐBody Components.
Fig. 14 Bumper End Cap Removal/InstallationÐXJ
Vehicles
Fig. 15 Bumper Guard Removal/InstallationÐXJ
Vehicles
JFRAME AND BUMPERS 13 - 7

YJ FRAME
INDEX
page page
Frame Alignment......................... 10
Frame Inspection/Measurements............. 10Frame Repair Service..................... 13
General Information........................ 8
GENERAL INFORMATION
FUNCTIONS
The JeeptYJ (Fig. 1) frame is the structural cen-
ter of the vehicle. In addition to supporting the body
and payload, the frame provides a station for the en-
gine. The vehicle body is attached to the frame with
holddowns (Figs. 2 and 3).
Fig. 1 JeepTYJ
13 - 8 FRAME AND BUMPERSJ

Fig. 2 Jeep
TYJ Body & Frame
JFRAME AND BUMPERS 13 - 9

CONSTRUCTION
The frame is constructed of high-strength channel
steel siderails and crossmembers. The crossmembers
join the siderails and retain them in alignment in re-
lation to each other. This provides resistance to
frame twists and strains.
FRAME ALIGNMENT
INCORRECT ALIGNMENT
Incorrect frame alignment is usually a result of:
²collision impact, or
²the vehicle being operated with excessive loads, or
²loads not positioned in a properly distributed man-
ner on the vehicle.
A mis-aligned frame will affect front axle and/or
rear axle alignment. It can cause excessive wear and
mechanical failures in the powertrain. Window glass
cracks and door opening/closing problems. Vehicle
performance can also be impaired.
RE-ALIGNMENT
With collision damage, it is important that the ex-
istence of any frame alignment damage be deter-
mined. If necessary, the frame should be correctly re-
aligned. Refer to the reference dimensions listed on
frame alignment dimension chart (Fig. 4).
FRAME INSPECTION/MEASUREMENTS
INSPECTION
Before proceeding with measurements, inspect all
components for visible damage and other metal dam-
age. Also, inspect all connections for loose and miss-
ing hardware.
All damaged areas must be repaired and/or the
components replaced, as necessary.
MEASUREMENTS
Measure the frame for mis-alignment with the
body attached to the frame. Figure 4 provides the
alignment reference dimensions. The following infor-
mation applies to all measurements.
(1) Place the vehicle on a level surface.
(2) If the vehicle is loaded, ensure that the vehicle
weight plus the payload does not exceed the gross ve-
hicle weight rating. Also, ensure that the load is dis-
tributed in the vehicle as evenly as possible.
(3) Measure the tire inflation pressures and adjust
the pressure, if necessary.
HORIZONTAL OR DIAGONAL FRAME MEASUREMENTS
Determine the frame horizontal non-square devia-
tion(s) according to the following procedure.
(1) Select several reference points along one frame
siderail, preferably at the crossmember junctions.(2) Transfer these reference points to the surface/
floor with a plumb bob. Paper sheets can be attached
to the surface below the reference points for better
measurement accuracy.
(3) Locate the reference points on the other frame
siderail and transfer them to the surface/floor with
the same procedure as above.
(4) Move the vehicle away and measure between
all the reference points diagonally from and parallel
to the siderails (Fig. 5). The measurements should
not differ by more than 6 mm (1/4 in).
(5) Measure the distance between the two front
reference points and the distance between the two
rear reference points. Divide each distance in half
and indicate the two half-way points on the surface/
floor. Designate the front point as ``1'' and the rear
point as ``2'' (Fig. 5).
(6) Place a chalk-line between points 1 and 2 and
``snap'' the string.
(7) Determine how close the center line is to the
diagonal intersection points A, B, C, D, E, and F in
Figure 5.
(8) The reference marks on the surface/floor will
provide an illustrated indication of the degree of
frame misalignment.
(9) A reference point transferred from one frame
siderail may be 3 mm (1/8 in) ahead or behind the
reference point from the opposite siderail.
(10) Frame bow to the side should not exceed 3
mm per 2,540 mm (1/8 inch per 100 inches) in
length.
(11) The overall width of the frame should not
vary more than 3 mm (1/8 in) from reference point-
to-reference point.
(12) Repeat steps (1) through (11) after straighten-
ing the frame to evaluate the effectiveness.
TWIST AND PARALLEL FRAME MEASUREMENTS
Determine the amount of frame twist and siderail
deviation according to the following procedure.
(1) Mark the vertical measurement reference
points under the frame siderails at 305-mm (12-in)
intervals starting at the rear frame crossmember.
(2) Measure the vertical distance up from a level
surface to each reference point located under the left
and right frame siderails.
(3) The distance to a reference point under one
frame siderail should be 3 mm (1/8 in) greater or less
than the point under the opposite siderail.
(4) Plot the measured vertical distances to scale on
a sheet of graph paper. Plot the distances so that the
frame siderails are located adjacent to each other.
Join the vertical distance points.
13 - 10 FRAME AND BUMPERSJ

Fig. 3 Body HoldDownsÐYJ Vehicles
JFRAME AND BUMPERS 13 - 11