If you do not have your manual - you can get a copy here:
http://www.vadengmpp.com/owners-manual/chevrolet/2006-Chevrolet-Suburban.pdf
Per the manual - Automatic Transmission DEXRON®-VI Automatic Transmission Fluid.
I would check with the placed that serviced the tranny. They probably changed the internal filter prior to the flush
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DEXRON®-VI ATF
General Motors Power train upgraded to DEXRON-VI ATF with the start of 2006 vehicle production.
Only 2005 and prior models that currently use DEXRON®-III may use DEXRON®-VI as a replacement.
All 2006 and future models that use DEXRON®-VI are to be serviced with DEXRON®-VI fluid only.
DEXRON®-VI is an improvement over DEXRON®-III in the following area:
DEXRON®-VI
Extended Factory Fill For Life 160,000 km (100,000 mi) For Cars and Light Duty Trucks*
80,000 km (50,000 mi) (Severe Use) For Cars and Light Duty Trucks*
Clutch Friction Stability Improved 100%
Clutch Durability Due To Fluid Improved 120%
Oil Film Thickness Increased 20%
Fluid Oxidation Improved 100%
Foam / Aeration Improved 150%
Shear Stability Improved 200%
* These ATF change intervals remain the same as DEXRON®-III for the time being.
2006 Transmission Fill and Cooler Flushing
Some new applications of the 6L80 six speed transmission will require the use of the J 45096 -- Flushing and Flow Tester to accomplish transmission fluid fill. It is highly recommended that the clean oil reservoir of the machine be purged of DEXRON®-III and filled with DEXRON®-VI.
General Motors has introduced a new ATF specification it has termed Dexron® VI. GM decided it needed to upgrade its ATF specification to accommodate the Hydra-Matic 6L80, its first 6-speed automatic. This fluid is the new service fill and factory fill specification for all Hydra-Matic GM transmissions. It will be used as a factory fill for all 2006 MY Hydra-Matic automatic transmissions starting on April 4, 2005, and it will be mandatory service fill by January 2007. Dexron® III(H) or Dexron® VI can be used for service fill until January 2007. Dexron® III(H) approvals will be valid until December 31, 2006. Dexron® VI is backward compatible with previous Dexron® formulations. Dexron® VI will be offered through GM Vehicle Care products in dealerships and service centers in Summer 2005.
GM believes this new ATF is two to three times better than the best Dexron® III(H) fluid on the market, today. Some of the enhancements of the Dexron® VI include significantly improved shift performance and fluid durability as well as superior pitting protection, oxidation stability, foaming protection, and shear stability.
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From my 2011 manual:
DEXRON®-VI Automatic Transmission Fluid.
Allison Transmission Only: For areas where ambient temperatures are
below -40°C (-40°F) use Synthetic Transmission Fluid approved to
Allison Transmission specification TES?295 (GM Part No. U.S. 12378515,
in Canada 88900701).
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If you have an Allison transmission - TranSynd is recommended by Allison. Your owners manual will indicate what is recommended by GM in the tranny.
I did a drain and fill twice with TranSynd to convert to full synthetic.
From a retired Allison engineer wrote the Allison TES-295 and TES-389 specifications:
All 06+ GM's came with DEX6, but the ALLISON S/N break point wasn't until mid year 06 - seal issues.
DEXRON-VI is not synthetic. It is made from a blend of Group II and Group III base oils plus the additives package. It does not contain any PAO (polyalphaolefin) which would make it a "true synthetic" Group IV like TranSynd and the other TES-295 approved products.
TranSynd is still the best option. Even though Allison changed seal materials to be compatible with DEXRON-VI, TranSynd will last longer and remain more stable over a given time period.
