Positioning:
The 1996 S420 represented the pinnacle of Mercedes-Benz's luxury sedan offering, targeting discerning clientele valuing comfort, advanced technology, and robust engineering. This manual caters to the preservation and maintenance of these high-end vehicles.
Competitors:
Competed directly with other flagship luxury sedans of the era, such as the BMW 7 Series (E38), Audi A8 (D2), Lexus LS 400, and Jaguar XJ.
Vehicle Features:
The W140 S-Class was renowned for its substantial build quality, advanced safety features (e.g., dual airbags, ABS, ASR), luxurious interior appointments, and smooth V8 power delivery.
Value:
Provides essential, official documentation for maintaining and repairing a complex luxury vehicle, crucial for preserving its performance, longevity, and resale value. Offers immediate access to critical repair data.
Engine System:
Complete coverage of the M119 4.2L V8 engine, including fuel injection, ignition, cooling, lubrication, and emissions control systems.
Transmission System:
Detailed diagnosis and repair procedures for the 4G-TRONIC 4-speed automatic transmission (722.3xx series).
Chassis System:
Comprehensive information on suspension (front and rear independent, multi-link rear), steering system (hydraulic power steering), and braking system (ABS, ASR, vented discs).
Electrical System:
Extensive wiring diagrams, diagnostic procedures for electronic control units (ECU), body control modules (BCM), lighting, power accessories, and integrated diagnostic system (SDS).
Body And Interior:
Repair and adjustment procedures for body panels, doors, windows, locks, seats, climate control, and interior trim components.
Maintenance Procedures:
Scheduled maintenance tasks including oil changes, filter replacements, fluid level checks, brake inspections, and belt inspections/replacements.
Diagnostic Procedures:
Troubleshooting guides based on symptoms, diagnostic trouble codes (DTCs), and specific procedures for using the Mercedes-Benz SDS (if applicable to the software).
Repair Procedures:
Step-by-step instructions for component removal, installation, overhaul, and adjustment for all major vehicle systems.
Technical Specifications:
Detailed specifications for torque values, clearances, fluid capacities, electrical parameters, and component tolerances.
Depth:
Comprehensive coverage suitable for professional technicians and advanced DIY enthusiasts, including detailed diagrams, schematics, and diagnostic flowcharts.
Format Details:
Digital software, likely in a searchable PDF or proprietary executable format, designed for easy navigation and quick access to information.
Quality:
High-resolution digital content providing clear text and detailed illustrations, diagrams, and schematics.
Type:
Not Applicable (Software)
Type:
Not Applicable (Software)
Engine Type:
V8, Naturally Aspirated
Displacement:
4.2 liters (4196 cc)
Bore X Stroke:
92.0 mm x 78.9 mm
Compression Ratio:
10.0:1
Horsepower:
275 hp @ 5700 rpm
Torque:
295 lb-ft @ 3900 rpm
Fuel Delivery:
Bosch Motronic M3.8.0 Fuel Injection System
Fuel Type:
Premium Unleaded Gasoline (91 octane or higher)
Ignition System:
Distributorless Ignition System (DIS) with coil-on-plug ignition (on later revisions).
Engine Control Unit:
Bosch LH-Jetronic / Motronic
Transmission Type:
4-speed Automatic
Transmission Model:
722.370 (4G-TRONIC)
Optional Transmission:
N/A for S420 in 1996
Transmission Features:
Lock-up torque converter, electronic shift control, winter/sport mode selection.
Fluid Type:
Mercedes-Benz Approved ATF (e.g., MB 236.1 or newer compatible)
Capacity Approximate:
8.5 - 9.5 liters (dependent on torque converter drain)
NHTSA Ratings:
Specific NHTSA ratings for 1996 models are not readily available in a standardized format as crash testing protocols have evolved significantly. However, the W140 was designed with substantial safety in mind for its era.
Active Safety:
Anti-lock Braking System (ABS), Acceleration Slip Regulation (ASR - Traction Control), Xenon Headlights (optional/standard depending on market).
Passive Safety:
Dual front airbags, side-impact protection, reinforced passenger cell, crumple zones, seatbelt pretensioners.
Infotainment System:
Bose premium sound system (optional), AM/FM cassette player with CD changer capability (optional). Features include automatic antenna and steering wheel audio controls (on some models).
Driver Assistance Features:
Cruise control, parking assist (optional), automatic climate control with dual-zone functionality, power-adjustable steering column with memory.
Connectivity Features:
Limited by modern standards; features such as telecommunications or early cellular phone integration were available as options or dealer-installed accessories.
Comfort Features:
Heated and ventilated seats (optional), power memory seats, dual-pane acoustic glass, interior ambient lighting, self-leveling suspension (optional).
Oil Change Interval:
Typically every 7,500 - 10,000 miles (12,000 - 15,000 km) or annually, whichever comes first, using synthetic oil.
Major Service Intervals:
Refer to the manual for specific mileage-based maintenance points (e.g., spark plugs at ~60,000 miles, transmission service, coolant flush).
Engine Oil Specification:
API SG, ACEA A2-96 or similar, SAE 0W-40 or 5W-40 synthetic oil is recommended.
Engine Oil Capacity:
Approximately 8.0 liters (with filter change)
Coolant Specification:
Mercedes-Benz Approved Antifreeze/Coolant (e.g., MB 325.0 or similar silicate-free long-life coolant).
Brake Fluid Specification:
DOT 4
Common Issues:
Window regulator failures, ignition coil issues (M119), ABS sensor faults, vacuum system leaks (causing various malfunctions), sagging headliner, potential for corrosion on older units, complex wiring harnesses require careful diagnosis.
Common Filter Part Numbers:
Oil Filter: Mann-Filter HU 713/1x or equivalent. Air Filter: Mann-Filter C36142/1 or equivalent.
Mercedes Benz Heritage:
Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, and safety, dating back to the invention of the automobile. The S-Class lineage represents the flagship model continuously evolving with technological advancements.
W140 Introduction:
The W140 generation was introduced in 1991 as the successor to the W126 S-Class. It was a significant redesign, larger and more technologically advanced, sometimes criticized for its size and perceived opulence compared to its predecessor.
Production Years:
W140 generation produced from 1991 to 1998. The S420 variant was available throughout this period.
Manufacturing Location:
Sindelfingen, Germany
Vehicle Awards:
While specific awards for the 1996 S420 are not widely publicized, the W140 generation consistently received accolades for its engineering, comfort, and safety from automotive publications of the era, cementing its status as a benchmark luxury sedan.
Consumer Ratings:
Consumer satisfaction ratings were generally high for build quality and comfort, though repair costs were acknowledged as being premium.
