These are transmissions for the 2002–2009 TrailBlazer, the midsize body-on-frame SUV on GM's GMT360 platform, and for its long-wheelbase sibling the TrailBlazer EXT, which runs to 2006. The TrailBlazer name was later revived for a small crossover; that is a different vehicle and nothing here fits it.
Every listing in this group is an automatic. No manual transmission appears, which reflects the vehicle — the TrailBlazer was not offered with one. The listings are divided by engine, by two-wheel or four-wheel drive, and for 2008 by the transmission's own identification code.
Chevrolet TrailBlazer used transmissions — options by year
| Years listed |
Type |
Engine |
Driveline |
Notes |
| 2002–2009 |
Automatic |
4.2L inline six |
4x2 and 4x4 listed apart |
The volume combination |
| 2003–2008 |
Automatic |
5.3L V8 |
4x2 and 4x4 |
EXT in the earlier years |
| 2006–2008 |
Automatic |
6.0L V8 |
4x4 only |
The SS driveline |
| 2008 |
Automatic |
4.2L inline six |
4x2: ID SAD or SWD |
Match the ID tag on your unit |
| 2008 |
Automatic |
4.2L inline six |
4x4: ID TAD or TWD |
Match the ID tag on your unit |
How to pick the right one
Three things decide it: the engine, the driveline and, for 2008, the identification code. The engine matters because the V8s use a stronger unit than the 4.2 six and the two are not interchangeable. The driveline matters because a four-wheel-drive unit carries a different tailhousing and output arrangement. The 2008 listings go one level further and separate four identification codes — SAD and SWD on two-wheel drive, TAD and TWD on four-wheel drive. That code is stamped on the transmission itself, so for a 2008 truck it is worth reading the tag on the unit you are replacing rather than ordering on the year alone. Check too whether yours is an EXT, since the long body was offered with combinations the standard body was not.
What usually goes wrong on these transmissions
The four-speed automatic behind the 4.2 six is the one that most often needs replacing, and the usual presentation is slipping in the upper gears or a complete loss of third and fourth. On this family that generally points to a worn clutch pack or a cracked reaction sun shell, neither of which is a service adjustment. Before committing, rule out the cheap faults that mimic it — a failed shift solenoid, low fluid, or a wiring fault at the case connector. A shudder that comes and goes at light throttle is usually the torque converter clutch and is often fluid related. The units behind the V8s are a heavier-duty design and fail less often, but the same diagnostic order applies. Each listing states its condition and the mileage options.
What ships with every unit
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Condition as listed — each product page states the condition and the mileage options, which are priced separately.
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VIN matched fitment — send us your VIN and we confirm the transmission application against your vehicle before the order ships.
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Written warranty — 6 months on these units, extendable to 3 years, parts only. Labour is not included unless you buy a separate agreement.
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Free freight anywhere in the lower 48, shipped on a pallet to a commercial address or a terminal.
Related reading: Chevrolet TrailBlazer used engines, GM 5.3L Vortec engine guide, GM 6.0L V8 engine guide, all engine guides.
Chevrolet TrailBlazer used transmissions — frequently asked questions
Was the Chevrolet TrailBlazer available with a manual transmission?
No. Every transmission listed for the 2002–2009 TrailBlazer is an automatic, which matches how the vehicle was built.
What do the 2008 codes SAD, SWD, TAD and TWD mean?
They are transmission identification codes stamped on the unit. SAD and SWD are two-wheel-drive units and TAD and TWD are four-wheel-drive. For a 2008 truck the year and engine alone do not identify which you need, so read the tag on the transmission you are replacing.
Does a 4.2 transmission fit a 5.3 TrailBlazer?
No. The V8s use a heavier-duty unit than the 4.2 inline six and the listings are separated by engine for that reason. Match the engine and the driveline together.
Will these fit a 2021 or newer Chevrolet TrailBlazer?
No. The revived TrailBlazer is a small crossover on a different platform with a different driveline. Everything listed here belongs to the 2002–2009 midsize SUV.
What comes with a used Chevrolet TrailBlazer transmission?
Each listing states its condition and its mileage options. Fitment is matched to your VIN before the order goes out, every unit carries a written warranty of 6 months, extendable to 3 years, parts only, and freight is free anywhere in the lower 48.
