2018 GMC Sierra 1500 transmission — (AT), 4x2, 5.3L, 8 speed, opt M5U price snapshot
- Low
- $2,504
- Average
- $3,210
- High
- $5,634

Year & trim-specific price guide
A used 2018 GMC Sierra 1500 transmission ((AT), 4x2, 5.3L, 8 speed, opt M5U) costs $2,504 to $5,634, with a median asking price of $3,012. Based on 33 priced salvage yard listings across the US, updated Aug 18, 2026. Prices exclude shipping, core charges, and installation.
Condition comparison
| Grade | Price range | Relative range | Listings |
|---|---|---|---|
| Grade AClean / low wear | $3,000–$3,900 | 6 | |
| Grade BStandard used | $2,800–$3,787 | 18 | |
| Grade CVisible wear | $2,800–$2,800 | 1 | |
| Grade XUngraded | $2,504–$5,634 | 8 |
Median by grade
Median asking price by seller-reported condition grade · $2,504–$5,634 overall range
Trim-specific context
This pricing covers the (AT), 4x2, 5.3L, 8 speed, opt M5U variant of the 2018 GMC Sierra 1500 transmission, based on 33 priced listings. Its $3,012 median is 14% above the 2018 GMC Sierra 1500 transmission overall median of $2,642.
There are 13 other transmission variants available for the 2018 GMC Sierra 1500.
Pricing is not a fitment guarantee. Match the VIN, part number, engine or drivetrain, and seller-listed variant before ordering.
Same year, other trims
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Common questions
Based on 33 priced salvage-yard listings, a used 2018 GMC Sierra 1500 transmission in the (AT), 4x2, 5.3L, 8 speed, opt M5U variant lists between $2,504 and $5,634, with a median asking price of $3,012.
In our current dataset, the (AT), 4x2, 5.3L, 8 speed, opt M5U variant appears only for the 2018 model year.