Allison 2550 Series

Allison 2550 Series

Category:

Description

RATINGS

Model Gross Input Torque(2) N*m Gross Input Power(2) kW (hp) Gross Input Torque(2)(3) N*m Gross Input Power(2)(3) kW (hp) GVW kg GCW kg
2550 General 780 224 (300) 895 224 (300) 13,600 13,600
2550 Non-North America School Bus 705 149(200) 750 149(200) 13,600 13,600
2500 SP Speciality Vehicles CONTACT YOUR ALLISON REPRESENTATIVE FOR DETAILS

DRIVETRAIN INTERFACES

  • Acceptable full-load engine governed speed: 2200 – 3800* rpm
  • Acceptable engine idle speed range (with transmission in drive): 500 – 820 rpm
  • Maximum output shaft speed at 105 km/hr (65 mi/hr): 4500 rpm

MOUNTING

  • To Engine: SAE No.3, SAE No.2

TORQUE CONVERTER

TYPE: One stage, three element, polyphase. Includes standard integral damper which is operational in lockup.

Model Stall Torque Ratio
TC-210 2.05
TC-211 1.91
TC-221 1.73
TC-222 1.58

MECHANICAL RATIOS

(Gear ratios do not include torque converter multiplication)

First 3.51 : 1
Second 1.90 : 1
Third 1.44 : 1
Fourth 1.00 : 1
Fifth 0.74 : 1
Sixth 0.64 : 1
Reverse -5.09 : 1

CONTROL SYSTEM

Description Allison 5th Generation Electronic Controls with closed loop adaptive shifts
Shift Sequences [C = Converter mode (lockup clutch disengaged); l = lockup mode (lockup clutch engaged)]

  • Option 1: 1C–[1l]–2C–2l–3l–4l–5l
  • Option 2: 1C–[1l]–2C–2l–3l–4l–5l–6l
Driver-to-Transmission Interface Cab-mounted shift selector
Communication Protocol – Engine/Vehicle Systems Interface SAE J1939, IESCAN, PT-CAN

PHYSICAL DESCRIPTION

Installation Length Dry Weight Depth below transmission centerline
SAE No.3 729 mm 150 kg
  • With Shallow Oil Sump (Standard): 272 mm
  • With deep Oil Sump (Optional): 285 mm
SAE No.2 73 mm 150 kg
  • With Shallow Oil Sump (Standard): 272 mm
  • With deep Oil Sump (Optional): 285 mm

TURBINE-DRIVEN POWER TAKE-OFF PROVISION

PTO drive Torque converter turbine-driven spur gear
PTO mounting pads Six-bolt, 3 o’clock and 9 o’clock positions (as viewed from rear)
PTO drive gear rating (continuous operation)
  • Using one PTO: 339 N•m
  • Total using two PTOs: 271 N•m
PTO drive gear ratio 1.00 x turbine speed
PTO drive gear 64 tooth

OIL SYSTEM

Allison approved fluids TES 295 and TES 389
Capacity, excluding external circuits
  • With deep Oil Pan: 14 litres
  • With Shallow Oil Pan: 12 litres
Spin on canister filter Standard

SPEEDOMETER PROVISIONS

  • Description: Non-zero-crossing square wave 8, 16 or 40 pulses per revolution of transmission output shaft
  • location: Electronic output from TCM

TACHOGRAPH PROVISION

  • Tonewheel: 6-tooth
  • Mounting:  M18 x 1.5 metric thread
  • location: Transmission rear cover

Additional information

Part Numbers

23011408, 23041448, 23011518