1998 JAGUAR X308 oil

The
Nivomat ride levelling system improves ride quality by al
lowing the use of softer road springs, while controlling the
effects on the suspension of a fully laden vehicle. The system uses special rear dampers in place of the normal units. There
are no other components in th e system. The ride levelling system is comple tely automatic, requiring no input from the
driver.
Ride levelling may be specified as an opti on on certain models; it is not available in north American markets. Ride levelling
and adaptive damping are mu tually exclusive options.
The Nivomat damper:
Su
pplements the load-carrying capacity of th
e road springs at high vehicle loads.
Uses road inputs to the
suspension to power the levelling function.
De

tects suspension height dire
ctly from road wheel travel.
Provi
des load-dependent spring rates; the ac
cumulator gas pressure increases with load.
Pr
ovides load-dependent damping; the fluid pressure increases with load.
Op

eration
F
ollowing an increase in vehicle loading,
the dampers adapt to maintain the height of the vehicle within its design range.
The system uses road inputs to the suspension to power the levelling action, and requires up to approximately two
kilometers of travel, following a change in load, to complete the process.
Normal movement of the suspension caus es a pumping action to occur within the damper, as a result of extension and
compression of the pump rod in the pump chamber. Hydraulic fluid is pumped from the pump cham ber into a high pressure
gas accumulator. The increase in gas pressure augments the force developed between th e vehicle axle and the body,
thereby providing lift.
It
em
De
scription
1Pi

ston rod
2Pum

p chamber
3High

pressure
gas accumulator
4Diaphragm
5Co
ntrol orifice
6Pump rod
7Low pressure gas ch

amber
8Low pressure oil

reservoir


Ride Levelling

A c
ontrol orifice in the pump rod determines the levelling height. When the damper is compressed, this orifice is covered.
When the damper extends, the control orif ice is uncovered, pressure is released to the low pressure oil reservoir and the
system ceases to rise. When the vehicle is high after unloading, the opened control or ifice allows fluid to be returned to the
low pressure oil reservoir, and the suspensi on returns to its normal unladen height.
Ad
aptive Damping

•
NOTE: Items 2 and 5 are ALWAYS located
on the passenger side of the vehicle
Adaptive damping enhances vehicle handli ng by the use of special dampers which are controlled by a dedicated control
module.
Adaptive damping may be specified as an option on certai n models. Adaptive damping and ride levelling are mutually
exclusive options. The adaptive damping system is completely automatic, requiring no input from the driver.
A d
aptive Dampers
The adaptiv
e dampers:
Are inst

alled in place of the normal dampers.
Can be identified

by the cable and connector at the top of the unit.
Have two settings; fi
rm and so
ft.
It
e
m
De
scr
iption
1Dam
p
er, front right-hand
2Accel
e
rometer, lateral
3Accel
e
rometer,
front vertical
4D
a
mper, rear right-hand
5Adaptive dampin
g control module (A
DCM)
6Accel
e
rometer, rear vertical
7D
amper, rear l
eft-hand
8Dam
p
er, front left-hand

R
ear Drive Axle/Differential - Rear Drive Axle and Differential
Description an
d Operation
Loca

tion
The differential
unit
is mounted between the wide mount ing bracket, pendulum assembly and the wishbone tie assembly.
Two tie rods are fitted between top rear of the final dr ive casing and the front of the wide mounting bracket.

Parts List
Description
The
type 14 HU final drive assembly is a hypoid unit with th
e pinion arranged on the cross-car centerline. The driveshaft
coupling utilizes a cassette type pinion oil seal, which is an in tegral part of the pinion flange. This type of seal cannot be
separated from the pinion fl ange and therefore may only be renewed as a complete seal / flange assembly
The axle shafts are driven by the output flanges which rotate on sealed bearings , these assemblies being retained in the
final drive unit by circlips.
Pinion Drive Flange / Seal Detail
• NOTE: The component parts are shown in an exploded view for clarity, this is NOT the fitted condition
It
em
Par
t Number
De
scription
1—F

inal Drive Unit
2—W

ide Mounting Bracket
3—Pen

dulum Assembly
4—Wi

shbone Tie Assembly
5—'A'

Frame

In
stallation

(and axle shaft if i
t
is to be re-used)
1. Installation is the re verse of the removal procedure, noting the
following.

2. Secure the axle shaft.
1.
Apply thread locking agent, to the SPLINE, as
indicated.
2. Refer to the illustration - do NOT re-use the original
nut.

3. Re
fer to the illustration.

4. Re
fer to the illustration.
E
n
sure that the match marks ar
e aligned prior to securing
the fixing.
5. Check and adjust as required, the final drive unit oil level.
6. Check and adjust as required, the rear wheel alignment, 204-
02.

6.
CAUTIO
N: If the gap CANNOT be achieved,
contact Jaguar Service
2. A gap smaller than specified will indicate an improperly fitted circlip. This may be rectified by
refitting or by the application of radial pressure
around the inner circum ference of the circlip
7. Verify t
hat the output shaft end-float is within specification

8. Re
fer to the illustration
If
app
ropriate realign the pr
eviously made match marks
9. Check the final drive oil level and adjust as required
10. Check and adjust rear wheel camber setting

11
.
Correct the final drive oil level as required.
12. Adjust the parking brak e cable as required.

12. R
emove the final dr
ive nose plate.
1. Remove the final drive nose plate bolts (4)
2. Remove the final drive nose plate
13. Position the axle assembly on its LH side and support it on
wooden blocks

14 . Re
move the wishbone
1. Remove the fixing, stabilizer bar link to wishbone
2. Remove the pivot nut
3. Remove pivot
4. Note the position of and remove the front spacer and
rear washers
5. Remove the wishbone
15. Repeat for the opposite hand

16 . R
emove the wishbone tie assembly
1. Remove the wishbone tie to final drive fixings (2)
2. Remove the washers (2)
3. Remove the wishbone tie assembly
4. Remove the washers (2)

17. R
emove the tie rods
1. Remove the tie rod to final drive fixings (2)
2. Remove the tie rods to wide mounting bracket
fixings (2)
3. Remove the tie rods
4. Note the position of and remove the spacers
18. Position the assembly for access to the 'A' frame to final drive
fixings, noting that oil may issue from the breather
19. Remove the 'A' frame assembly

11
. R
efer to the illustration
12. Ensure that the spring pan and wishbone location reflects the
original condition

13 . R
efer to the illustration
14. Check and adjust as required, the final drive unit oil level
15. Check and adjust as required, the rear wheel alignment, 204-
02.