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2021 GMC SIERRA 3500HD
6.6L V8 Duramax Diesel•4WD•AUTOMATIC•diesel•turbo
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Repairs0Labor505Torque1468Fluid10DTC1866Battery1Maintenance0Recalls0
Fluid · Automatic Transmission

Automatic Transmission

for 2021 GMC Sierra 3500HD 6.6L V8 Duramax Diesel · 4WD
Fluid Type
Allison TES 668 ATF
Spec: TES 668
Capacity
27qt
25.54 L
Drain & Refill
7.4 qt
7 L
Change Interval
50,000 mi
80,450 km
Data quality
Book-style estimate
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Notes

Allison 1000 6-speed. Full capacity includes torque converter. Standard drain-and-fill service.

Other fluid systems on this vehicle

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