frame JEEP YJ 1995 Service And Service Manual

FRAME AND BUMPERS
CONTENTS
page page
BUMPERS.............................. 5
BUMPERS............................. 16FRAME................................. 1
FRAME................................ 10
FRAME
INDEX
page page
Frame Dimensions......................... 1
Front Skid Plate........................... 1
Fuel Filler Hose Splash ShieldÐXJ Vehicles...... 4
Fuel Tank Skid Plate........................ 3Fuel Tank Support Strap..................... 4
General Information........................ 1
Transfer Case Skid Plate.................... 3
GENERAL INFORMATION
Jeep XJ Vehicles (Fig. 1) and the cab section of
Jeep are constructed as a unitized body and frame.
Jeep XJ unibodies are constructed from special
high-strength steel and coated metals. These types of
metals reduce weight and provide strength.
A vehicle constructed as a unibody reacts differ-
ently to the impact of a collision. While the damage
at the immediate point of impact is easily recogniz-
able, the damage must be diagnosed to expose it.
With unibody construction, there are five logical ar-
eas to examine to expose damage:
²Damage at the immediate point of impactÐpri-
mary damage.²The other (lessor) body damageÐsecondary dam-
age.
²Damage to the exterior trim and other surface-at-
tached components.
²Damage to the mechanical components.
²The interior trim and accessory damage.
When there is damage to a vehicle, the alignment
points must be returned too specifications.
FRAME DIMENSIONS
Frame dimensions are listed in millimeter scale.
All dimensions are from center to center of Principal
Locating Point (PLP), or from center to center of PLP
and fastener location (Fig. 2).
FRONT SKID PLATE
REMOVAL
(1) Remove the screws that attach skid plate to
side sills (Fig. 3).
(2) Remove the nuts that attach the skid plate to
the crossmember (Fig. 3).
(3) Remove the skid plate from the vehicle (Fig. 3).
INSTALLATION
(1) Position the skid plate at front crossmember
and side sills (Fig. 3).
(2) Install the nuts to attach the skid plate to
crossmember.
(3) Install the screws to attach skid plate to side
sills.
Fig. 1 JeepÐXJ
JFRAME AND BUMPERS 13 - 1

Fig. 2 Frame Alignment Reference DimensionsÐXJ Vehicles
13 - 2 XJÐFRAMEJ

TRANSFER CASE SKID PLATE
REMOVAL
(1) Support the skid plate.
(2) Remove the bolts that attach the skid plate to
the transmission support crossmember and frame sill
(Fig. 4).
(3) Remove the support and skid plate from the ve-
hicle.
INSTALLATION
(1) Position and support the skid plate at the
frame sill and transmission support crossmember
(Fig. 4).(2) Attach the skid plate to the frame sill and
crossmember with bolts. Tighten bolts to 22 Nzm (16
ft. lbs.) torque.
FUEL TANK SKID PLATE
REMOVAL
(1) Position a support under skid plate.
(2) Remove the bolts that attach skid plate to un-
derbody side rails (Fig. 5 and 6).
(3) Remove the support and the skid plate from
the vehicle.
INSTALLATION
(1) Position and support skid plate under fuel
tank.
(2) Install bolts to attach the skid plate to under-
body rails. Tighten the bolts to 50 Nzm (37 ft. lbs.)
torque.
(3) Remove the support from under skid plate.
Fig. 3 Front Skid Plate Removal/Installation
Fig. 4 Transfer Case Skid Plate
Fig. 5 Fuel Tank Skid Plate W/O Trailer Hitch Or Tow
Hook
Fig. 6 Fuel Tank Skid Plate With Trailer Hitch Or
Tow Hook
JXJÐFRAME 13 - 3

FUEL FILLER HOSE SPLASH SHIELDÐXJ
VEHICLES
REMOVAL
(1) Remove the screws that attach fuel filler hose
splash shield to wheelhouse panel and frame rail
(Fig. 7).
(2) Remove the hose splash shield from wheel-
house panel and frame rail (Fig. 7).
INSTALLATION
(1) Position fuel filler hose splash shield at wheel-
house panel and frame rail.
(2) Install screws to attach splash shield to wheel-
house panel and frame rail.
FUEL TANK SUPPORT STRAP
SERVICE INFORMATION
XJ fuel tank support straps are attached to the un-
derside of the vehicle via T-slots and hole-slots in the
frame members.
REMOVAL
(1) If equipped, position a support under skid
plate.
(2) If equipped, remove the bolts that attach skid
plate to underbody side rails.
(3) If applicable, remove the support and skid plate
from fuel tank.
(4) Support fuel tank.
(5) Loosen nut from fuel tank support strap bolt to
allow bolt head to be removed from hole-slot in frame
member (Fig. 8).
(6) Remove the strap T-end from frame member T-
slot (Fig. 9).
(7) Separate support strap from fuel tank and re-
move it from vehicle.
INSTALLATION
(1) Position support strap around fuel tank.
(2) Insert strap T-end in frame member T-slot.
(3) Insert bolt in hole-slot in frame member.
Tighten nut on the bolt until bolt-head and T-end are
seat and strap is tight against the bottom of fuel
tank.
(4) Remove the support from the fuel tank.
(5) If removed, position and support and the fuel
tank skid plate under the fuel tank.
(6) If applicable, install the bolts that attach the
skid plate to the underbody side rails. Tighten the
bolts to 50 Nzm (37 ft. lbs.) torque.
(7) Remove the support from under the skid plate.
Fig. 7 Fuel Filler Hose Splash ShieldÐXJ Vehicles
Fig. 8 Fuel Tank Support StrapÐXJ Vehicles
Fig. 9 Fuel Tank Support StrapsÐXJ Vehicles
13 - 4 XJÐFRAMEJ

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
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
23, Body Components.
REAR TOW HOOK
REMOVAL
(1) Remove the bolts that attach tow hook bracket
to the frame rail and reinforcement bracket (Fig. 16).
The reinforcement bracket is held on the
frame rail with two blind rivets.
(2) Remove the bracket and tow hook from frame
rail.
INSTALLATION
(1) Position bracket and tow hook on the frame
rail.
(2) Install bolts that attach tow hook bracket to
frame rail and reinforcement bracket. Tighten bolts
to 75 Nzm (55 ft. lbs.) torque.
Fig. 15 Bumper Guard Removal/InstallationÐXJ
VehiclesFig. 16 Rear Tow HookÐXJ Vehicles
JXJÐBUMPERS 13 - 9

FRAME
INDEX
page page
Frame Dimensions........................ 13
Frame Repairs........................... 13
Frame Straightening....................... 13
Fuel Tank Skid Plate....................... 15
General Information....................... 10Generator Splash Shield.................... 13
Safety Precautions and Warnings............. 10
Tow Hooks.............................. 13
Transfer Case Skid Plate.................... 15
SAFETY PRECAUTIONS AND WARNINGS
WARNING: USE EYE PROTECTION WHEN GRIND-
ING OR WELDING METAL, SERIOUS EYE INJURY
CAN RESULT.
BEFORE PROCEEDING WITH FRAME REPAIR IN-
VOLVING GRINDING OR WELDING, VERIFY THAT
VEHICLE FUEL SYSTEM IS NOT LEAKING OR IN
CONTACT WITH REPAIR AREA, PERSONAL INJURY
CAN RESULT.
DO NOT ALLOW OPEN FLAME TO CONTACT
PLASTIC BODY PANELS. FIRE OR EXPLOSION CAN
RESULT.
WHEN WELDED FRAME COMPONENTS ARE RE-
PLACED, 100% PENETRATION WELD MUST BE
ACHIEVED DURING INSTALLATION. IF NOT, DAN-
GEROUS OPERATING CONDITIONS CAN RESULT.
STAND CLEAR OF CABLES OR CHAINS ON
PULLING EQUIPMENT DURING FRAME STRAIGHT-
ENING OPERATIONS, PERSONAL INJURY CAN RE-
SULT.
DO NOT VENTURE UNDER A HOISTED VEHICLE
THAT IS NOT SUPPORTED ON SAFETY STANDS,
PERSONAL INJURY CAN RESULT.
CAUTION: Do not reuse damaged fasteners, quality
of repair would be suspect.
Do not drill holes in top or bottom frame rail
flanges, frame rail failure can result.
Do Not use softer than Grade 3 bolts to replace
production fasteners, loosening or failure can re-
sult.When using heat to straighten frame components
do not exceed 566ÉC (1050ÉF), metal fatigue can re-
sult.
Welding the joints around riveted cross members
and frame side rails can weaken frame
GENERAL INFORMATION
The Jeep YJ (Fig. 1) frame is the structural center
of the vehicle. In addition to supporting the body and
payload, the frame provides a station for the engine.
The vehicle body is attached to the frame with hold-
downs (Fig. 2 and 3).
Fig. 1 JeepÐYJ
13 - 10 YJÐFRAMEJ

Fig. 2 YJ Body & Frame
JYJÐFRAME 13 - 11

Fig. 3 Body HoldDownsÐYJ Vehicles
13 - 12 YJÐFRAMEJ

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 STRAIGHTENING
When necessary, a conventional frame that is bent
or twisted can be straightened by application of heat.
The temperature must not exceed 566ÉC (1050ÉF).
The use of a specially designed heat crayon can de-
termine the desired temperature. Excessive heat will
decrease the strength of the metal and result in a
weakened frame.
Welding the joints around riveted cross members
and frame side rails is not recommended.
A straightening repair process should be limited to
frame members that are not severely damaged.
FRAME REPAIRS
DRILLING HOLES
Do not drill holes in frame side rail top and bottom
flanges, metal fatigue can result causing frame fail-
ure. Holes drilled in the side of the frame rail must
be at least 38 mm (1.5 in.) from the top and bottom
flanges.
Additional drill holes should be located away from
existing holes.
WELDING
Use MIG, TIG or arc welding equipment to repair
welded frame components.
Frame components that have been damaged should
be inspected for cracks before returning the vehicle
to use. If cracks are found in accessible frame com-
ponents perform the following procedures.
(1) Drill a hole at each end of the crack with a 3
mm (O.125 in.) diameter drill bit.
(2) Using a suitable die grinder with 3 inch cut off
wheel, V-groove the crack to allow 100% weld pene-
tration.
(3) Weld the crack.
(4) If necessary when a side rail is repaired, grind
the weld smooth and install a reinforcement channel
(Fig. 4) over the repaired area.
If a reinforcement channel is required, the
top and bottom flanges should be 0.250 inches
narrower than the side rail flanges. Weld only
in the areas indicated (Fig. 4).
FRAME FASTENERS
Bolts, nuts and rivets can be used to repair frames
or to install a reinforcement section on the frame.
Bolts can be used in place of rivets. When replacing
rivets with bolts, install the next larger size diameter
bolt to assure proper fit. If necessary, drill the hole
out just enough to receive the bolt.Conical-type washers are preferred over the split-
ring type lock washers. Normally, grade-5 bolts are
adequate for frame repair.Grade-3 bolts or softer
should not be used.Tightening bolts/nuts with the
correct torque, refer to the Introduction Group at the
front of this manual for tightening information.
FRAME DIMENSIONS
Frame dimensions are listed in millimeter scale.
All dimensions are from center to center of Principal
Locating Point (PLP), or from center to center of PLP
and fastener location (Fig. 5).
TOW HOOKS
REMOVAL
(1) Remove the two bolts that attach the tow hook
to the bumper rail and to the frame rail.
(2) Remove the tow hook.
INSTALLATION
(1) Position the tow hook on the bumper rail and
frame rail.
(2) Install the attaching bolts. Tighten the bolts to
102 Nzm (75 ft. lbs.) torque.
GENERATOR SPLASH SHIELD
REMOVAL
(1) Remove the shield retaining nut and washer
(Fig. 6) from the engine oil pan stud (2.5L engines
only).
(2) Pry the serrated retainers from the frame rail
holes at each side of the vehicle.
(3) Pry the serrated retainers from the fan shroud
holes (Fig. 6).
(4) Remove the shield from the vehicle.
Fig. 4 Frame Reinforcement
JYJÐFRAME 13 - 13

Fig. 5 Frame Alignment DimensionsÐYJ Vehicles
13 - 14 YJÐFRAMEJ