Automatic transmission
Used Allison Automatic Transmissions
Allison builds true torque-converter automatics used in medium-duty trucks, vocational trucks, buses and emergency vehicles. Send us your ID plate information and we search supplier sources for a matching used unit.
Allison Automatic at a glance
- Type
- Fully automatic, torque converter with planetary gearsets
- Common series
- 1000/2000 Series, 3000 Series, 4000 Series
- Forward speeds
- Typically 5 or 6, depending on model and configuration
- Typical applications
- Box trucks, refuse, dump, utility, fire and rescue, school and transit buses
Identification tag
How to identify your Allison transmission
Allison transmissions have a metal ID plate on the transmission housing. It lists the model (for example a 3000 or 4000 Series model with a suffix such as RDS, HS or EVS), the serial number and an assembly part number.
The serial number and assembly number matter most. They help identify the control generation, PTO provisions and other details that the series number alone does not show.
01A true automatic, not an automated manual
An Allison uses a torque converter and planetary gears. There is no clutch pedal and no clutch to wear. That is different from automated manuals like Eaton UltraShift Plus, Volvo I-Shift or Detroit DT12, which shift a gear-and-clutch transmission by computer.
02Series, model suffix and gear count
The 1000/2000 Series is common in medium-duty trucks, while the 3000 and 4000 Series cover heavier vocational and bus work. Model suffixes identify the intended duty, and the number of forward speeds varies by model. Matching series and suffix is the starting point.
03TCM, controls generation and shifter
Electronically controlled Allisons rely on a transmission control module (TCM), a shift selector and a vehicle harness. Different control generations are not always interchangeable. The TCM may need to be reprogrammed or matched to the engine and vehicle, so tell us whether you need the transmission alone or with its TCM.
04PTO, retarder and cooler
Many vocational Allisons run a PTO, and some have an integral output retarder. Note whether yours has either, and check the cooler line fittings, so the replacement fits without surprises.
05Core and exchange
Core charges or exchange terms may apply depending on the supplier. If they do, they are confirmed on your quote before you commit, along with availability and freight.
Configuration
What we'll ask to match your unit
- What model, serial number and assembly part number are on the ID plate?
- Which series is it (1000/2000, 3000 or 4000)?
- Does it have a PTO or an output retarder?
- What engine is it behind, and what is the truck year, make and VIN?
- Do you need the TCM, shift selector or harness as well?
- What type of work does the truck do?
FAQ
Allison Automatic questions
Is an Allison the same as an automated manual transmission?
No. An Allison is a torque-converter automatic. Automated manuals such as Eaton UltraShift Plus, Volvo I-Shift and Detroit DT12 are gear-and-clutch transmissions with automated shifting.
Can I swap a 3000 Series for a 4000 Series?
Not as a direct replacement. They differ in size, mounting, torque capacity and controls. Replace with the same series and model whenever possible.
Will my old TCM work with a used Allison?
Sometimes. It depends on the control generation and calibration. Your Allison-capable shop can confirm whether the TCM needs reprogramming.
What does the suffix like RDS or EVS mean?
The suffix describes the intended duty, such as rugged-duty vocational or emergency vehicle use. Send it with the rest of the plate information.
Do you have Allison transmissions on hand?
We do not hold inventory. We search supplier sources nationwide and confirm availability, condition details and freight on your quote.
Ready when you are
Need a Allison Automatic? Send the tag number.
Have your engine serial number or transmission tag and VIN handy. If you don't, we'll help you find them.
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