GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 6 of 6
  1. #1

    Default Transmisson Temp

    I have a 2008 Silverado 4.3 V6 What Is the max Safe transmisson temp? I have seen 228 Deg in Traffic. Would like to know what others have seen Over 200 Seems High to me.

  2. #2


    228 is still in the safe range.
    If I remember correctly most trans fluid doesnt start breakdown until around 270, but that depends on brand, age, additives added, etc.
    It wouldnt hurt to put an inline aux trans cooler on, they can be purchased for under a $100 at most auto parts stores and can reduce temps as much as 20deg in traffic(even larger reductions can be seen on open highway driving) depending on where its placed.
    And certain additives are pretty helpful at reducing friction.
    It's almost impossible to cool off an automatic transmission to much.

  3. #3


    228 is still WAY too hot in terms of longevity. A well cooled transmission should be no hotter than an engine, and sometimes as low as 160. 210 is MAX in my opinion. Keeping the trans in the range of the engine temp, and even just slightly cooler will prolong the useful life of the fluid at least twice over, especially with Dexron III

    Highly recommend looking into an auxiliary cooler. B&M is a good company.

    '93 Pontiac Bonneville SE | Series I Buick 3800 L27 | Dark Yellow Green | 3.06:1 | | 225/60 TripleTreds 2/9/08 | 106k | The Mean Green Machine
    '04 Chevrolet Avalanche 1500 Z71 4x4 | Gen III Vortec 5300 LM7 | Summit White | 3.73:1 | XM, Bose 6 Disc Changer | 12-way Heated Leather | 58k

  4. #4

    Default Transmission Temp

    Mobil 1 makes a synthetic automatic tranny fluid which will run cooler and not break down as easly. It can be purchase at walmart or most parts stores. Also Earls make great coolers in just about any size you need.

  5. #5


    Yeah that seems really high to me. My allison in my 3500 silverado never goes above 200 when I'm pulling my 28' enclosed trailer loaded up w/ my car and equipment. I'd see about getting a tranny cooler is your truck doesn't already have one.
    2004 silverado 3500 SRW 4x4 8.1l w/ allison 5spd

    HPTuners flash tuned
    Trueflow Cold air intake w/ K&N panel filter
    Gibson 4" Catback side swept exhaust
    MB motoring 16" mirror polished wheels
    Hankook dynapro ATm 285/75/16 High/Low beam Fog conversion kit
    Hunter truck accessories bull bar
    Upgraded mirrors to power extended flex mirrors

  6. #6
    Legend tlperry68's Avatar
    Join Date
    Oct 2008
    Huntington Beach, CA


    When I pull my 33' trailer in 100 degree heat the tranny stays around 200 degrees. I see that the tranny temp typically stays about 80 to 100 degrees hotter than the ambient temperature.
    Trevor - Huntington Beach, CA
    2007 GMC 2500 4X4

Similar Threads

  1. First post: multi year 2500 chevy 2wd transmisson problems
    By Nothing_Lost in forum GM Powertrain
    Replies: 0
    Last: 01-17-2010, 06:50 PM
  2. outside temp on DIC
    By Earl27 in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 3
    Last: 07-20-2009, 08:55 AM
  3. Temp
    By TJ smith in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 8
    Last: 05-13-2009, 03:02 PM
  4. transmisson shifts to soon.
    By in forum GM Powertrain
    Replies: 2
    Last: 04-05-2009, 10:47 PM
  5. Chevy Truck Transmisson Upgrade Help
    By joemud in forum GM Powertrain
    Replies: 2
    Last: 02-06-2009, 10:24 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts