Mercedes M-Class springs, shocks and struts
variable rate spring
M-Class coil springs are progressive similar to full hydropneumatic
suspensions. If one wants to improve M-Class suspensions one should
make some of the early years softer for large potholes so they are
comparable to the hydropneumatic. Some later years thud at 30 km/h
on poor surfaced roads (e.g. asphalt partially broken off).
The front torsion bars can be adjusted, 5-10 full turns counter clockwise
loosening the bolt lowers it by about 0.75 inches, softening the ride
somewhat.
The larger moments of inertia around the roll axis amplify roll motions.
MB sedans exhibit the same motion but it's harder to notice since it's
less amplified. Overall it's a well designed double wishbone suspension
with a low ratio of unsprung to sprung mass, about 3 times less than in
a comparable live axle design.
Model year 2002 changes
The stabilizer diameter was increased on the front axle to 36 mm
(ML55) and 35 mm (ML320, ML500). The rear stabilizer bar was increased
to 22 mm diameter (ML55). Revised shock valving was introduced to the
front and rear double tube shocks, and this includes replacement shocks
for earlier model years.
L4000-146715
M-Class rear hydropneumatic spring legs (ArvinMeritor, Bilstein, KYB, Sachs)
| Mercedes-Benz part number |
|
|
|
|
top plate |
color code |
| 163 320 00 13 |
98-99 ML320 ML430
(shock 163 320 00 30) |
FST0026 |
NMI0029 |
HIGHWAY |
|
yellow dot |
| 163 320 02 13 |
98-00 w/ rear carrier to 93893 |
|
|
HD |
|
|
| 163 320 04 13 |
99-00 to 93893 w/o rear carrier |
|
|
HIGHWAY |
|
|
| 163 320 05 13 |
00-01 w/o wheel carrier |
|
|
HIGHWAY |
|
|
| 163 320 06 13 |
00-01 w/ wheel carrier |
|
|
HD |
|
|
| 163 320 07 13 |
00 ML55 w/o wheel carrier |
|
|
HIGHWAY |
|
|
| 163 320 09 13 |
00 from 93894 |
|
|
HIGHWAY |
|
|
| 163 320 10 13 |
00 w/ rear carrier from 93894 |
|
|
HD |
|
|
| 163 320 11 13 |
00-01 ML320 ML430 (Sachs 290 055)
(shock 163 320 04 30; FST0044; 1E07A) |
FST0045 |
NMI0029 |
HIGHWAY |
17 mm green |
green red white |
| 163 320 11 13 |
00-01 (Sachs 290 055)
(shock 163 320 04 30; FST0044; 1F05C)
(spring embossed KHW 00 45 CC) |
FST0045 |
NMI0029 |
HIGHWAY |
19 mm blue |
blue pink |
| 163 320 12 13 |
00-01 ML55 to 289559 (Sachs 290 209)
(shock 163 320 05 30; FST0047) |
FST0048 |
NMI0029 |
HIGHWAY |
|
|
| 163 320 13 13 |
00-01 w/ rear carrier (Sachs 290 208) |
FST0046 |
NMI0143 |
HD |
|
white red (LG) |
| 163 320 13 13 |
00-01 w/ rear carrier (Sachs 290 208) |
FST0046 |
NMI0143 |
HD |
|
WH RD BL BL |
| 163 320 18 13 |
02+ ML320, ML350, ML500 w /rear carrier; replacement for 01-03 ML320, ML430 w/ rear carrier |
FST0046 |
NMI0143 |
HD |
|
|
| 163 320 21 13 |
02+ ML 55 from 289560; also replacement for earlier ML55s |
|
|
|
|
|
| 163 320 23 13 |
2002-05 ML320, ML350, ML500
also replacement for 01-03 ML320, ML430 from 93894 w/o spare tire carrier (screwdriver end) |
ME01007
revalved |
NMI0029 |
HIGHWAY |
|
|
| 163 320 24 13 |
replacement for 98-00 ML320, ML430 to 93893 w/o spare tire carrier (torx end, a bit more thread, 23 can be used instead w/ dremelling lower mounting hole) |
ME01007
revalved |
NMI0029 |
HIGHWAY |
|
|
| 163 320 25 13 |
replacement for earlier ML320s |
|
|
|
|
|
| Original 99 ML320 (7/31/98)
This label was attached at the middle of the rear coil spring of a 1999 ML320. A yellow dot was on the same coil.
2003 ML500
On the very right a label from a 03 ML500 by ack,
with revalved shocks.
|
|
Plot of spring length versus load for
various ML (and G) springs
Rear Hydrostrut (Spring and Shock) and Front Shock Install (Mercedesshop)
Rear Hydrostrut (Spring and Shock) Install (Mercedesshop)
Harald Pietschmann's
ML320 torsion bar adjustment can raise or lower the front
M-class (W163) with ZF Sachs Twin-Tube Dampers
The classic twin-tube damper used in the W163 M-class has the
advantages of low friction, high ride comfort, multi-step
piston and base valves which allow variation in characteristic curves,
and short length.
ZF Sachs Super Gas shock absorber warranty
Bilstein makes shock absorbers for the M-Class
Rear: BE5-2983, BE5-2984 (98-99) (no longer in production), BE5-2985 (1/99-05, but can be fitted to 98s)
Front: BE5-6456-H0 (97-98 and 1/99-05)
They are all HD (HEAVY DUTY). Stick with MB OEM shocks (rated HIGHWAY) for a softer ride.
Did you know that Bilstein shock absorbers world premiered in 1957 on a
Mercedes-Benz?
1998-2003 ML320 Bilstein rear hydropneumatic struts L4000-86676 or L4000-159265.
Bilstein COMFORT, HEAVY DUTY, SPORT shocks explained
M-Class front shock absorber part numbers
163 326 00 00 ML320/ML430 (discontinued)
163 326 03 00 ML55 (discontinued)
163 326 05 00 ML55 to 289559
163 326 08 00 98-01 ML320/ML430
163 326 09 00 98-01 ML55 from 289560
163 326 11 00 02+ ML320/ML430/ML500/ML55 from 145273 (revalved)
163 326 12 00 02+ replacement for ML320/ML430 to 145272 (revalved)
163 323 01 85 shock mounting kit (98-00 front)
Eibach makes a PRO-KIT for the M-Class: PRO-KIT 2558.120.
Eibach has been making springs since 1951 and is now the #1
choice of performance enthusiasts worldwide.
H&R makes sport springs for the M-Class: 29497-1, 29497-2. They also
produce stiff torsion bars with 38 mm diameter for the front and
23 mm diameter for the rear.
Using Bilstein shocks BE5 6456 front and BE5 2985 rear with H&R springs
lowers the rear of an ML 55 AMG about 30 mm. Front is adjustable.
Kleemann makes springs for the
M-Class, part number 004 163 00 06.
Monroe makes truck shock absorbers for the front of the M-Class. Monroe
Reflex part number 911219.
Voigtland makes tuned sport springs for the W163, W164 M-Class and R-Class. They supply NASCAR.
Car and Driver article: "M Stands for More", 5 pages
dynamics + suspension
shoptalk
|
The only limit to the M-Class 4WD system is the friction of the
road. - Gerhard Fritz
|
Wolfgang's ML Page
