Page 2 of 2 FirstFirst 12
Results 11 to 14 of 14

Thread: Pulled the trigger on the 383

  1. #11
    Certifiable Vanatic Z-Machine (aka VanZack)'s Avatar
    Join Date
    Sep 2013
    Location
    Rockport, WA
    Posts
    597
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    👍

    I would keep it in third on any uphills. The way it was explained to me by a transmission tech is, the speed of the engine determines the speed of the trans pump that circulates the fluid. In fourth, it doesn't circulate fast enough for adequate cooling. Once you get that trans temp gauge, you'll be able to watch it. Heat is the big killer of auto trannies.
    1969 G10 108, 307 V8, TH350, 3.08 gears
    1966 G10 Panel, 194 I6, three on the tree (I think it's an old Ma Bell van)

  2. #12
    VCVC Member lvjjj's Avatar
    Join Date
    Sep 2007
    Location
    BLAINE WA USA
    Posts
    4,015
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Z-Machine (aka VanZack) View Post
    I would keep it in third on any uphills. The way it was explained to me by a transmission tech is, the speed of the engine determines the speed of the trans pump that circulates the fluid. In fourth, it doesn't circulate fast enough for adequate cooling. Once you get that trans temp gauge, you'll be able to watch it. Heat is the big killer of auto trannies.
    I do pull it down to 3rd on "hills." Sometimes hard to tell what is a hill and what isn't. If it starts to lug at all I pull it down. Although its hard to tell if its lugging as the 383 is so torquey. Also use 3rd in town traffic. So its a matter of paying real close attention, which I always do when towing.

    I've discovered a forum called GMT 400 which is for '88 to '98 GM trucks. Most of them have been telling me the 4L60E tranny is a weak link and suggest I replace it with a 4L80E. So far the 60 is working ok even though I drove it 40,000 miles without flushing the fluid, getting it flushed this week.
    LARRY OF THE PACIFIC NW
    1965, 292, TH350
    purchased Nov. 22, 1970

  3. #13
    Certifiable Vanatic Leroy Jackson's Avatar
    Join Date
    Oct 2012
    Location
    California
    Posts
    524
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    What kind of transmission are we talking about? 200R4, 700R4 or an electronic trans like a 4l80e?

    The 200 and 700 series with the tv cables.. definitely don't run them in overdrive under heavy loads. Wire up the converter lockup to work off a switch too. The overdrive clutch packs are tiny in these transmissions.

    The 4l80e is plenty strong to keep in overdrive. The computer will also control the gear, pressure and lock out depending on throttle position and speed. The only real reason to shift down would be to keep an engine in the meat of its torque curve.

    The 6l85e or 6l80e I would downshift to 3rd as well. They are just an electronic version of the 700r4. Pretty much the same wimpy planetary a d clutch pack.
    The Raped Ape
    1970 G-20 Krylon black
    Swing up cargo doors
    Supercharged 383
    4L80E transmission
    Detroit trutrac rear limited slip

  4. #14
    Certifiable Vanatic Leroy Jackson's Avatar
    Join Date
    Oct 2012
    Location
    California
    Posts
    524
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    One more item to note, chevy auto 4 speeds transmission are 1:1 in third, direct connection to the crank and they are the strongest in this gear. In over drive, the torque is being put through an additional clutch pack and depending on the model, may only be 1 or two plates thick. Under heavy loads, they can slip.
    The Raped Ape
    1970 G-20 Krylon black
    Swing up cargo doors
    Supercharged 383
    4L80E transmission
    Detroit trutrac rear limited slip

User Tag List

Posting Permissions

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