What kind of transmission fluid does a 2006 Chevy 2500hd Allison take?
The transmission fluid typically required for a 2006 Chevrolet Silverado 2500HD with the Allison 1000 automatic is Dexron III automatic transmission fluid.
Dexron VI is a common modern substitute and is generally backward-compatible with Dexron III, but you should verify the exact specification for your specific truck by checking the owner's manual or consulting a GM/Allison service representative.
Understanding the specification and compatibility
Knowing which ATF to use matters for shift quality, temperature control, and long-term durability in the Allison 1000. The following options are commonly considered for this transmission.
- Dexron III ATF (GM Dexron III) — the traditional specification for many 2001–2007 Allison 1000 transmissions in GM heavy-duty pickups.
- Dexron VI ATF — backward-compatible and widely used as a replacement; confirm that your exact transmission revision is approved by GM/Allison for Dexron VI.
In practice, Dexron VI is frequently used as a convenient replacement due to availability and performance, but always confirm the specific specification for your build before changing fluids.
How to verify the correct specification for your vehicle
To ensure you use the right ATF, follow these steps to confirm the correct specification for your exact production date and transmission revision.
- Consult the owner's manual or an official GM service bulletin for the exact ATF specification for your year/model and VIN.
- Inspect the transmission dipstick or pan label for the stated specification (Dexron III or Dexron VI).
- Ask an Allison-certified technician or your GM dealer to confirm the approved ATF for your vehicle's transmission revision.
- Choose an ATF that explicitly meets the Dexron III or Dexron VI specification as applicable, and avoid non-Dexron fluids.
Following these steps helps ensure proper shifting performance and transmission longevity.
Summary
For a 2006 Chevy Silverado 2500HD with the Allison 1000, Dexron III ATF has long been the standard specification. Dexron VI is commonly used as a modern substitute when approved for the exact transmission revision. Always verify with the owner's manual or a GM/Allison technician to confirm the correct specification for your vehicle, and use fluids that meet the Dexron standard to maintain shifting quality and durability.
What transmission fluid does Allison recommend?
Allison recommends using an Allison Approved TES 668™ fluid for modern transmissions, as it is their newest, high-performance synthetic fluid. For older products, TES 295® is also a highly recommended and proven fluid, and TES 668 is backward-compatible and can be mixed with it. The company no longer recommends C4 fluids or Dexron-VI for commercial on-highway transmissions.
Recommended fluids
- TES 668™: Allison's newest, high-performance synthetic fluid, recommended for all on-highway products in the 1000, 2000, 3000, and 4000 series transmissions. It offers enhanced performance, durability, and the longest drain intervals.
- TES 295®: A proven and highly recommended fluid that is still a great choice, especially for those with older transmissions. TES 668 is backward compatible with TES 295.
- TES 468®: Can be used anywhere TES 295 is specified.
- TES 389®: Can be used in traditional on-highway products but does not provide the same drain intervals as TES 295.
Fluids to avoid
- C4 fluids: No longer recommended for any commercial on-highway transmissions.
- DEXRON®-VI: No longer recommended for any commercial on-highway transmissions.
Important considerations
- For the best performance and longest service life, use Allison Approved fluids. You can find a complete list of approved fluids on the Allison Transmission website.
- While TES 668 is backward compatible with TES 295, if you are switching from a non-approved fluid like Dexron-VI, it is best to perform a flush and fill to get the maximum benefit of the new fluid and its extended drain intervals, according to this Facebook post.
What kind of transmission fluid does a 2006 Chevy 2500HD take?
DEXRON-VI Automatic Transmission Fluid (ATF). 1.32 Gallons (5 L).
What transmission fluid does a 2006 Allison Transmission take?
Allison recommends TES 668® Approved Fluids to enhance transmission performance and durability in all operating environments.
What kind of transmission fluid does a 2006 Duramax take?
The 2006 Duramax transmission fluid type depends on the transmission model: the Allison 1000 requires Dexron VI automatic transmission fluid, while the ZF S6-650 manual transmission uses GM TranSynd Full Synthetic. Dexron VI is the standard automatic transmission fluid for General Motors vehicles from 2006 onward, so any 2006 Duramax with an automatic transmission should use it.
Automatic transmission
- Fluid Type: Dexron VI Automatic Transmission Fluid (ATF)
- Capacity: 12.7 quarts (total capacity), with a service refill capacity of 7.4 quarts.
- Note: Dexron VI is backward compatible with previous transmissions that used Dexron III, but only Dexron VI should be used in 2006 and newer vehicles that require it.
Manual transmission
- Fluid Type: GM TranSynd Full Synthetic
- Capacity: 5.8 quarts
