Collection: Used Buick Transmissions For Sale

Browse Buick Transmissions by Year

Year-specific pages coming online weekly — text us your VIN and we will match you to the right Buick transmission from our verified inventory today.

Buick Transmissions We Cover

Real transmissions from our warehouse, VIN-matched and ready to ship. Nearly every Buick transmission is a GM corporate unit shared with Chevrolet, Pontiac, Cadillac, and GMC — which means the RPO code, not the badge on the trunk, tells you what fits. Two exceptions worth knowing: the Cascada runs an Aisin unit from its Opel platform, and the V8 Lucerne and supercharged Park Avenue Ultra run the heavy-duty 4T80-E.

GM 4T65-E 4-Speed FWD

LaCrosse, Allure, Regal, Century 3.1L/3.8L, Lucerne V6, Park Avenue. The volume Buick transaxle of the 1990s–2010s. Highest demand.

GM 4T60-E 4-Speed FWD

Older Park Avenue, Riviera, LeSabre (1990s). Direct predecessor to the 4T65-E — not interchangeable with it despite the family resemblance.

GM 4L60-E 4-Speed RWD/4WD

Roadmaster, older RWD Riviera, Estate Wagon. Classic GM body-on-frame longitudinal 4-speed shared across the whole GM truck and RWD line.

GM 6T70 6-Speed FWD/AWD

LaCrosse 3.6L, Enclave, Regal. The 6-speed transverse transaxle for the V6 lineup — higher torque capacity than the 6T40/6T45.

GM 6T40 / 6T45 6-Speed FWD

Verano, Encore 1.4T, Regal 2.0T, LaCrosse 2.4L. Compact-class 6-speed for the smaller-displacement Buick engines.

GM 9T50 / 9T65 9-Speed FWD/AWD

LaCrosse 2017+, Regal 2018+, Envision, Encore GX. The modern Buick 9-speed — TCM calibration revision matters on a swap.

GM 6F35 6-Speed FWD

Older Encore variants, certain Cascada builds. Compact 6-speed automatic — confirm against the RPO before ordering.

Aisin AF40 / TF-80SC 6-Speed (Cascada)

Buick Cascada (Opel-platform import). Aisin-supplied 6-speed — a completely different unit from the GM 6T-series. Never cross-shop with Verano or Regal.

GM 4T80-E 4-Speed V8 FWD

Lucerne 4.6L Northstar V8, Park Avenue Ultra supercharged. Heavy-duty FWD 4-speed built for V8 torque — not a 4T65-E.

GM VT40 CVT

Encore GX 1.3T, modern Encore variants. Belt-and-pulley CVT for the compact crossovers — fluid service history is critical on these.

TH-400 / 700R4 RWD (Classic)

Older Roadmaster, Electra (1980s–1990s), Estate Wagon. Classic GM body-on-frame 3-speed and 4-speed automatics — restoration demand.

More Buick Transmissions

Plus 4T65-E HD (supercharged 3800), 6T75 (Enclave), Enclave AWD transfer units, vintage Dynaflow and Super Turbine builds, and special-order requests — text us your VIN.

Trustpilot

Why Buy a Used Buick Transmission from Auto Power Source

Buick is a GM corporate brand, and its transmission catalog reflects that: the 4T65-E in a LaCrosse is the same family that ran in Pontiac Grand Prix and Chevy Impala, the 4L60-E in a Roadmaster is the GM truck and RWD-car 4-speed, and the 6T70 and 9T50 are shared across Chevrolet, GMC, and Cadillac. That parts-sharing works in your favor on availability, but it means the badge on the trunk tells you almost nothing — the RPO code does. Two Buick units sit outside the GM corporate line: the Cascada's Aisin AF40 (it rode in on the Opel platform) and the 4T80-E, a heavy-duty FWD 4-speed built only for V8 and supercharged applications.

Every Buick transmission we sell has been pulled from a low-mileage donor, cataloged by VIN, and held in our climate-controlled warehouse. Each unit goes through our six-step inspection: VIN-matching, ASE Shift-Testing through every gear under load, noise verification, full visual inspection of case, pan, and bellhousing, multi-angle photography for your approval, and palletized freight shipping. The 9T50 and 9T65 get TCM calibration-revision verification, and VT40 CVT units get belt-and-pulley inspection plus fluid-service review. Rejected units never reach the buyer.

You pay a fraction of dealer-new pricing for the same GM engineering, ship free on a heavy-duty pallet anywhere in the continental U.S., and you have 30 days from delivery to return for any reason — no restocking fees. Up to a 3-year warranty covers you if anything goes wrong after install, and our six-step inspection has held our fitment-related return rate at 0% across 100,000+ shipments.

Your Buick Transmission Options: Compared

Most Buick owners face four real choices when their transmission fails:

Tested used OEM hits the sweet spot — same engineering as new, fraction of the cost.

Buick Transmission Buying Guide

Because Buick shares almost its entire transmission catalog with the rest of GM, matching is done on RPO code and drivetrain rather than on model name. Five things to verify before buying a used Buick transmission:

1. Match on the RPO code, not the badge. The RPO (Regular Production Option) code on the glovebox or trunk label identifies the exact transmission GM built into your car. A LaCrosse, Impala, and Grand Prix of the same year can all carry a 4T65-E with different internals and calibration. Send us the RPO or the VIN and we match on the code.
2. 4T65-E and 4T80-E are not the same transmission. The 4T80-E is a heavy-duty FWD 4-speed built for V8 torque — Lucerne 4.6L Northstar and the supercharged Park Avenue Ultra. Different case, bellhousing, and final drive from the 4T65-E. There is also a 4T65-E HD variant behind the supercharged 3800; confirm which you need before ordering.
3. Cascada is an Opel import and runs an Aisin unit. The Cascada carries the Aisin AF40 / TF-80SC 6-speed from its European platform, not a GM 6T-series transaxle. It will not cross-shop with a Verano, Regal, or Encore of the same year no matter how similar the listing looks.
4. 6T70 vs 6T40 / 6T45 is decided by engine displacement. The 6T70 sits behind the 3.6L V6 (LaCrosse, Enclave, Regal V6); the 6T40 and 6T45 sit behind the 1.4T, 2.0T, and 2.4L. Different torque capacity, bellhousing, and final drive. Match to your engine, not to your model year.
5. Modern 9-speeds and CVTs need calibration and service history. The 9T50 and 9T65 received calibration revisions over their production life and need the current TCM software flashed at install. VT40 CVT longevity depends almost entirely on fluid-service intervals — ask us for the donor's history, we pull it on request.

Our ASE-certified technicians verify every one of these points against your VIN before any transmission ships.

Learn More: Buick Transmission Guides

Practical guides from our team — how to install a used Buick transmission, what to check on delivery, and what really matters when buying online.

APS Preinstallation Guide

Step-by-step guide to properly installing a used transmission — what to inspect, prep, and torque before first start.

Post-Install Maintenance Checklist

Keep your used transmission running like new — the break-in period, fluid intervals, and warning signs to watch for.

5 Things to Know Before Buying

Warranty terms, VIN matching, mileage, testing, return policy — the checklist every buyer should run through.

After Delivery: Inspection Guide

What to check the moment your transmission arrives — freight damage, matching numbers, and what to photograph.

Frequently Asked Questions

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