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City Bus

Product

Overview

The city bus is a 40-foot low-floor diesel transit vehicle for high-frequency urban service. Its defining feature is a step-free entrance: the Low-Floor Center Section drops the cabin floor to near curb height, and a kneeling Air Suspension plus a fold-out Wheelchair Ramp make the vehicle accessible to wheelchair users, strollers, and passengers with limited mobility. It is engineered for durability under stop-and-go duty cycles, frequent door operation, and high passenger turnover.

Construction

The bus is built around the Low-Floor Chassis Frame, a welded steel ladder frame whose center section is dropped to create the low floor. A rear-mounted Diesel Engine drives through an Automatic Transmission to the Drive Axle, a portal axle whose hub-reduction gearboxes raise the halfshafts clear of the aisle. Steering loads are carried by the Front Portal Axle.

Braking and ride quality depend on two air systems. The Air Brake System supplies dual-circuit pneumatic brakes with ABS, fed from an engine-driven compressor and reservoir tanks. The same supply feeds the Air Suspension, which levels the body and kneels at stops. The passenger envelope is formed by the aluminum-framed Body Shell, entered through pneumatic Passenger Door units. Inside, the Passenger Seating provides fixed transit seats and grab rails, while the driver works from the Driver Area. Route information is shown on the front Destination Sign, and the rear-mounted Cooling System pack manages engine temperature.

City Bus parts and their functions

17 top-level parts · 40,967 parts in total · full bill of materials below
City Bus parts diagram: 1 low-floor chassis frame, 2 diesel engine, 3 automatic transmission, 4 drive axle, 5 front portal axle, 6 air brake system, 7 air suspension, 8 body shell, 9 passenger door, 10 passenger seating, 11 driver area, 12 destination sign, 13 wheelchair ramp, 14 HVAC unit, 15 electrical system, and 2 more. 40,967 parts in 17 top-level items.
City Bus parts diagram. Numbers match the table below; each box is one top-level part or assembly with what it contains.
#PartQtyWhat it does
1 Low-Floor Chassis Frame 7 parts 1× Welded steel ladder frame with dropped center section.
2 Diesel Engine 28 parts 1× rear-mounted
3 Automatic Transmission 5 parts 1× 6-speed torque-converter automatic.
4 Drive Axle 4 parts 1× Rear portal drive axle for low-floor layout.
5 Front Portal Axle 3 parts 1× portal
6 Air Brake System 13 parts 1× Full-air dual-circuit braking with ABS.
7 Air Suspension 7 parts 1× Electronically leveled air-bag suspension with kneeling.
8 Body Shell 22 parts 1× Aluminum-framed monocoque body.
9 Passenger Door 9 parts 2× Pneumatic inward-gliding double-leaf door.
10 Passenger Seating 9 parts 1× Fixed transit seats with grab rails.
11 Driver Area 7 parts 1× Driver cockpit with seat and controls.
12 Destination Sign 6 parts 1× Front LED route and destination display.
13 Wheelchair Ramp 4 parts 1× Manual fold-out accessibility ramp.
14 HVAC Unit 5 parts 1× roof unit
15 Electrical System 19 parts 1× 24V electrical and lighting system.
16 Cooling System 9 parts 1× Rear-mounted engine cooling pack.
17 Wheel Assembly 5 parts 6× 6 wheels

3D model

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Build & assembly graph

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Bill of materials for City Bus

17 top-level lines · 227 rows shown · 40,967 parts total · indented to 3 levels
# Item / sub-assembly Part no. Qty/assy Ext. qty Parts Type
1 Low-Floor Chassis Frame 7 parts city-bus-chassis 1× 1 724 assembly
1.1 Frame Rail city-bus-frame-rail 2× 2 · part
1.2 Low-Floor Center Section city-bus-low-floor-section 1× 1 · part
1.3 Fastener Set fastener-set 1× 1 · part
1.4 Body Bolt city-bus-body-bolt 260× 260 · part
1.5 Hex Nut city-bus-hex-nut 200× 200 · part
1.6 Washer city-bus-washer 200× 200 · part
1.7 Frame Bracket & Node city-bus-frame-bracket 60× 60 · part
2 Diesel Engine 28 parts city-bus-engine 1× 1 816 assembly
2.1 Engine Block city-bus-engine-block 1× 1 · part
2.2 Piston city-bus-piston 6× 6 · part
2.3 Crankshaft city-bus-crankshaft 1× 1 · part
2.4 Turbocharger 3 parts city-bus-turbocharger 1× 1 5 assembly
2.4.1 Turbo Housing city-bus-turbo-housing 1× 1 · part
2.4.2 Ball Bearing ball-bearing 2× 2 · part
2.4.3 Oil Seal oil-seal 2× 2 · part
2.5 Fuel Injector city-bus-fuel-injector 6× 6 · part
2.6 Aftertreatment Module 2 parts city-bus-aftertreatment 1× 1 2 assembly
2.6.1 Diesel Particulate Filter city-bus-dpf 1× 1 · part
2.6.2 SCR Catalyst city-bus-scr-catalyst 1× 1 · part
2.7 Oil Pump city-bus-oil-pump 1× 1 · part
2.8 Piston Ring city-bus-piston-ring 18× 18 · part
2.9 Connecting Rod city-bus-connecting-rod 6× 6 · part
2.10 Bearing Shell city-bus-bearing-shell 26× 26 · part
2.11 Poppet Valve city-bus-valve 24× 24 · part
2.12 Valve Spring city-bus-valve-spring 24× 24 · part
2.13 Valve Train Component city-bus-valve-train 24× 24 · part
2.14 Cylinder Head city-bus-cylinder-head 1× 1 · part
2.15 Camshaft city-bus-camshaft 1× 1 · part
2.16 Cylinder Liner city-bus-cylinder-liner 6× 6 · part
2.17 Flywheel & Housing city-bus-flywheel 1× 1 · part
2.18 High-Pressure Fuel Pump & Rail city-bus-high-pressure-pump 1× 1 · part
2.19 Charge Air Cooler city-bus-intercooler 1× 1 · part
2.20 DEF Tank & Dosing Module city-bus-def-tank 1× 1 · part
2.21 Exhaust Pipe & Clamp city-bus-exhaust-pipe 5× 5 · part
2.22 Fuel Tank city-bus-fuel-tank 1× 1 · part
2.23 Fuel Line city-bus-fuel-line 6× 6 · part
2.24 Engine Sensor city-bus-engine-sensor 22× 22 · part
2.25 Engine Gasket & Seal city-bus-engine-gasket 40× 40 · part
2.26 Engine Bolt & Stud city-bus-engine-bolt 520× 520 · part
2.27 Connector connector 60× 60 · part
2.28 Oil Seal oil-seal 6× 6 · part
3 Automatic Transmission 5 parts city-bus-transmission 1× 1 10 assembly
3.1 Gearbox Housing gearbox-housing 1× 1 · part
3.2 Torque Converter city-bus-torque-converter 1× 1 · part
3.3 Planetary Gear Set city-bus-planetary-set 1× 1 · part
3.4 Oil Seal oil-seal 3× 3 · part
3.5 Ball Bearing ball-bearing 4× 4 · part
4 Drive Axle 4 parts city-bus-drive-axle 1× 1 13 assembly
4.1 Open Differential 4 parts differential 1× 1 6 assembly
4.1.1 Differential Case diff-case 1× 1 · part
4.1.2 Side Gear side-gear 2× 2 · part
4.1.3 Pinion Gear pinion-gear 2× 2 · part
4.1.4 Cross Pin cross-pin 1× 1 · part
4.2 Portal Gearbox city-bus-portal-gearbox 2× 2 · part
4.3 Axle Housing city-bus-axle-housing 1× 1 · part
4.4 Oil Seal oil-seal 4× 4 · part
5 Front Portal Axle 3 parts city-bus-front-axle 1× 1 7 assembly
5.1 Steering Knuckle city-bus-steering-knuckle 2× 2 · part
5.2 Ball Bearing ball-bearing 4× 4 · part
5.3 Axle Housing city-bus-axle-housing 1× 1 · part
6 Air Brake System 13 parts city-bus-air-brake-system 1× 1 728 assembly
6.1 Air Compressor city-bus-air-compressor 1× 1 · part
6.2 Air Reservoir Tank city-bus-air-tank 2× 2 · part
6.3 Brake Chamber 1 parts city-bus-brake-chamber 4× 4 1 assembly
6.3.1 O-Ring Set oring-set 1× 4 · part
6.4 ABS Module 2 parts city-bus-abs-module 1× 1 97 assembly
6.4.1 Electronic Control Unit 4 parts + deeper › ecu 1× 1 93 assembly
6.4.2 Wheel Speed Sensor city-bus-wheel-speed-sensor 4× 4 · part
6.5 Coolant Hose coolant-hose 4× 4 · part
6.6 Air Line Fitting city-bus-air-fitting 320× 320 · part
6.7 Air Line city-bus-air-line 60× 60 · part
6.8 Air Valve city-bus-air-valve 22× 22 · part
6.9 Brake Disc city-bus-brake-disc 6× 6 · part
6.10 Brake Pad Set city-bus-brake-pad 6× 6 · part
6.11 Air Disc Brake Caliper city-bus-brake-caliper 6× 6 · part
6.12 Body Bolt city-bus-body-bolt 80× 80 · part
6.13 Cable Tie & Harness Clip city-bus-cable-tie 120× 120 · part
7 Air Suspension 7 parts city-bus-air-suspension 1× 1 120 assembly
7.1 Air Spring Bag city-bus-air-bag 6× 6 · part
7.2 Leveling Valve city-bus-leveling-valve 4× 4 · part
7.3 Shock Absorber city-bus-shock-absorber 6× 6 · part
7.4 Air Line Fitting city-bus-air-fitting 40× 40 · part
7.5 Air Line city-bus-air-line 12× 12 · part
7.6 Air Valve city-bus-air-valve 4× 4 · part
7.7 Body Bolt city-bus-body-bolt 48× 48 · part
8 Body Shell 22 parts city-bus-body-shell 1× 1 21,367 assembly
8.1 Aluminum Body Frame city-bus-aluminum-frame 1× 1 · part
8.2 Side Panel city-bus-side-panel 8× 8 · part
8.3 Roof Panel city-bus-roof-panel 1× 1 · part
8.4 Windshield windshield 1× 1 · part
8.5 Passenger Window city-bus-window 12× 12 · part
8.6 Fastener Set fastener-set 2× 2 · part
8.7 Body Frame Extrusion city-bus-frame-extrusion 260× 260 · part
8.8 Frame Bracket & Node city-bus-frame-bracket 480× 480 · part
8.9 Body Rivet city-bus-rivet 16000× 16,000 · part
8.10 Body Bolt city-bus-body-bolt 1400× 1,400 · part
8.11 Hex Nut city-bus-hex-nut 900× 900 · part
8.12 Washer city-bus-washer 900× 900 · part
8.13 Floor Panel city-bus-floor-panel 42× 42 · part
8.14 Floor Covering Sheet city-bus-floor-covering 6× 6 · part
8.15 Interior Panel city-bus-interior-panel 96× 96 · part
8.16 Window Seal & Bonding city-bus-window-seal 14× 14 · part
8.17 Skirt Panel city-bus-skirt-panel 14× 14 · part
8.18 Trim Clip city-bus-trim-clip 1200× 1,200 · part
8.19 Exterior Lamp city-bus-exterior-lamp 26× 26 · part
8.20 Exterior Mirror city-bus-mirror 2× 2 · part
8.21 Wiper & Washer System city-bus-wiper-system 1× 1 · part
8.22 Fire Suppression System city-bus-fire-suppression 1× 1 · part
9 Passenger Door 9 parts city-bus-passenger-door 2× 2 59 assembly
9.1 Pneumatic Door Actuator city-bus-door-actuator 1× 2 · part
9.2 Door Panel city-bus-door-panel 2× 4 · part
9.3 Door Seal city-bus-door-seal 1× 2 · part
9.4 Door Leaf city-bus-door-leaf 2× 4 · part
9.5 Door Drive Mechanism city-bus-door-drive 1× 2 · part
9.6 Door Safety Sensor city-bus-door-sensor 2× 4 · part
9.7 Air Line Fitting city-bus-air-fitting 8× 16 · part
9.8 Body Bolt city-bus-body-bolt 36× 72 · part
9.9 Connector connector 6× 12 · part
10 Passenger Seating 9 parts city-bus-passenger-seating 1× 1 719 assembly
10.1 Seat Assembly 5 parts seat-assembly 30× 30 7 assembly
10.1.1 Seat Frame seat-frame 1× 30 · part
10.1.2 Seat Foam seat-foam 2× 60 · part
10.1.3 Seat Cover seat-cover 1× 30 · part
10.1.4 Seat Motor seat-motor 2× 60 · part
10.1.5 Seat Heater Mat seat-heater 1× 30 · part
10.2 Grab Rail city-bus-grab-rail 8× 8 · part
10.3 Seat Mounting Hardware city-bus-seat-mount 30× 30 · part
10.4 Body Bolt city-bus-body-bolt 240× 240 · part
10.5 Stanchion city-bus-stanchion 24× 24 · part
10.6 Handrail Fitting city-bus-handrail-fitting 190× 190 · part
10.7 Stop Request Button city-bus-stop-button 14× 14 · part
10.8 Flip-Up Seat city-bus-flip-seat 2× 2 · part
10.9 Wheelchair Backrest & Restraint city-bus-wheelchair-restraint 1× 1 · part
11 Driver Area 7 parts city-bus-driver-area 1× 1 426 assembly
11.1 Seat Assembly 5 parts seat-assembly 1× 1 7 assembly
11.1.1 Seat Frame seat-frame 1× 1 · part
11.1.2 Seat Foam seat-foam 2× 2 · part
11.1.3 Seat Cover seat-cover 1× 1 · part
11.1.4 Seat Motor seat-motor 2× 2 · part
11.1.5 Seat Heater Mat seat-heater 1× 1 · part
11.2 Steering Wheel 3 parts steering-wheel 1× 1 4 assembly
11.2.1 Wheel Rim Core wheel-rim-core 1× 1 · part
11.2.2 Airbag Module airbag-module 1× 1 · part
11.2.3 Steering Control Switch control-switches 2× 2 · part
11.3 Dashboard 4 parts dashboard 1× 1 313 assembly
11.3.1 Infotainment Head Unit 5 parts + deeper › infotainment-unit 1× 1 304 assembly
11.3.2 Instrument Cluster instrument-cluster 1× 1 · part
11.3.3 HVAC Unit 5 parts + deeper › hvac-unit 1× 1 7 assembly
11.3.4 Dashboard Trim dash-trim 1× 1 · part
11.4 Instrument Cluster instrument-cluster 1× 1 · part
11.5 Driver Partition city-bus-driver-partition 1× 1 · part
11.6 Body Bolt city-bus-body-bolt 40× 40 · part
11.7 Trim Clip city-bus-trim-clip 60× 60 · part
12 Destination Sign 6 parts city-bus-destination-sign 1× 1 4,984 assembly
12.1 LED Matrix Panel city-bus-led-matrix 1× 1 · part
12.2 Electronic Control Unit 4 parts ecu 1× 1 93 assembly
12.2.1 Bare PCB pcb-bare 1× 1 · part
12.2.2 Microcontroller mcu 1× 1 · part
12.2.3 CAN Transceiver can-transceiver 1× 1 · part
12.2.4 SMD Passive (R/C/L) smd-passives 90× 90 · part
12.3 LV Wiring Harness 4 parts lv-harness 1× 1 54 assembly
12.3.1 Wire Bundle wire-bundle 1× 1 · part
12.3.2 Connector connector 40× 40 · part
12.3.3 Fuse Box fuse-box 1× 1 · part
12.3.4 Relay relay 12× 12 · part
12.4 LED city-bus-led 4800× 4,800 · part
12.5 Sign Driver Board city-bus-sign-pcb 12× 12 · part
12.6 Body Bolt city-bus-body-bolt 24× 24 · part
13 Wheelchair Ramp 4 parts city-bus-wheelchair-ramp 1× 1 15 assembly
13.1 Ramp Plate city-bus-ramp-plate 1× 1 · part
13.2 Fastener Set fastener-set 1× 1 · part
13.3 Ramp Drive city-bus-ramp-drive 1× 1 · part
13.4 Body Bolt city-bus-body-bolt 12× 12 · part
14 HVAC Unit 5 parts hvac-unit 1× 1 7 assembly
14.1 Blower Motor blower-motor 1× 1 · part
14.2 Evaporator evaporator 1× 1 · part
14.3 PTC Heater Core heater-core 1× 1 · part
14.4 Cabin Air Filter cabin-filter 1× 1 · part
14.5 HVAC Actuator hvac-actuator 3× 3 · part
15 Electrical System 19 parts city-bus-electrical 1× 1 10,769 assembly
15.1 12 V Battery lv-battery 2× 2 · part
15.2 LV Wiring Harness 4 parts lv-harness 1× 1 54 assembly
15.2.1 Wire Bundle wire-bundle 1× 1 · part
15.2.2 Connector connector 40× 40 · part
15.2.3 Fuse Box fuse-box 1× 1 · part
15.2.4 Relay relay 12× 12 · part
15.3 Fuse Box fuse-box 1× 1 · part
15.4 Lighting Set 3 parts city-bus-lighting 1× 1 15 assembly
15.4.1 Headlight city-bus-headlight 2× 2 · part
15.4.2 Interior Light city-bus-interior-light 12× 12 · part
15.4.3 Wire Bundle wire-bundle 1× 1 · part
15.5 Insulated Wire (cut length) city-bus-wire 2200× 2,200 · part
15.6 Crimp Terminal city-bus-crimp-terminal 4400× 4,400 · part
15.7 Connector connector 380× 380 · part
15.8 Fuse city-bus-fuse 90× 90 · part
15.9 Multiplex I/O Node city-bus-multiplex-node 12× 12 · part
15.10 Electronic Control Unit 4 parts ecu 16× 16 93 assembly
15.10.1 Bare PCB pcb-bare 1× 16 · part
15.10.2 Microcontroller mcu 1× 16 · part
15.10.3 CAN Transceiver can-transceiver 1× 16 · part
15.10.4 SMD Passive (R/C/L) smd-passives 90× 1,440 · part
15.11 Camera city-bus-camera 6× 6 · part
15.12 Passenger Counter Sensor city-bus-passenger-counter 4× 4 · part
15.13 PA Speaker city-bus-pa-speaker 10× 10 · part
15.14 Battery Cable & Isolator city-bus-battery-cable 1× 1 · part
15.15 Alternator city-bus-alternator 2× 2 · part
15.16 Starter Motor city-bus-starter 1× 1 · part
15.17 Cable Tie & Harness Clip city-bus-cable-tie 900× 900 · part
15.18 Ticket Machine & Validator city-bus-ticket-machine 3× 3 · part
15.19 LED city-bus-led 1200× 1,200 · part
16 Cooling System 9 parts city-bus-cooling 1× 1 90 assembly
16.1 Radiator radiator 1× 1 · part
16.2 Coolant Pump coolant-pump 1× 1 · part
16.3 Coolant Hose coolant-hose 4× 4 · part
16.4 Coolant coolant 1× 1 · part
16.5 Blower Motor blower-motor 1× 1 · part
16.6 Coolant Hose & Clamp city-bus-coolant-fitting 18× 18 · part
16.7 Saloon Convector Heater city-bus-heater 8× 8 · part
16.8 Heater Pipe & Hose city-bus-heater-hose 16× 16 · part
16.9 Body Bolt city-bus-body-bolt 40× 40 · part
17 Wheel Assembly 5 parts wheel-assembly 6× 6 9 assembly
17.1 Alloy Wheel alloy-wheel 1× 6 · part
17.2 Tire tire 1× 6 · part
17.3 TPMS Sensor tpms-sensor 1× 6 · part
17.4 Lug Nut lug-nut 5× 30 · part
17.5 Valve Stem valve-stem 1× 6 · part

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Sourcing: possible vendors

Browse the supplier directory → Prices, MOQ, and lead times are algorithmic estimates, not quotes, and not claims about these companies. Company mappings are curated by keyword; est. price band $500k–$60M. How estimates work
VendorHQSpecialtyMOQLead time
🇨🇳CRRC
crrcgc.cc ↗
Beijing, CN Rolling stock & rail systems made to order 40–72 wks
🇫🇷Alstom
alstom.com ↗
Saint-Ouen, FR Rail rolling stock made to order 40–72 wks
mobility.siemens.com ↗ Munich, DE Rail systems made to order 40–72 wks
🇨🇭Stadler Rail
stadlerrail.com ↗
Bussnang, CH Rail rolling stock made to order 40–72 wks
🇺🇸Wabtec
wabteccorp.com ↗
Pittsburgh, US Rail equipment made to order 40–72 wks

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