Announcement

Collapse
No announcement yet.

DOHC 3400 Transmision problems

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • DOHC 3400 Transmision problems

    so, here it is..
    so i have a 1991 Pontiac Grand Prix. it has about 350k on the clock with a rebuilt transmission. A couple months ago i drove it to my national guard unit which is about 2 hrs away from me. it drove perfect with no problems. It sat for 2 weeks while i was gone for training . when i returned i drove it back home and it drove perfect until i step foot in MO. It had a hard time shifting . so i put some lucus oil stop leak/slip in it and it worked fine. I took it drag racing and it drove fine there but once again i got to the dragstrip and it was shifting weird. come to find out my transmission fluid was a little low so i filled it up on the way home. i let it sit for a couple days and went to go wash it and it shifted fine to the car wash.Upon driving it home . i got stopped at a stop light and it didn't want to go anywhere at all..i had to have one foot on the brake and one foot on the gas for it to engage into 1st gear. The same thing with reverse , had to have one foot on the brake and one foot on the gas to engage reverse. I've been told the transmisson is SHOT and i have to rebuild it again..
    So i was hoping someone could help me on here.. Before we start digging into the transmission i hope its something simple.. but when i put it in drive or reverse it doesn't "shift hard" or "click" into gear.
    this is a "family car" thats been in the family for almost 20 years. dont want to get rid of it but its taking up garage space.
    thank you

  • #2
    Foot on the brake has NOTHING to do with whether it shifts into gear or not. Brakes don't work that way.

    Is the fluid level still low? HOW did the fluid level get to be low--does the trans leak externally, or is the fluid being consumed in the engine due to a defective vacuum modulator?

    When was the last time you replaced the trans filter?

    Is the fluid burnt-looking, or still nicely red?

    If you don't want to "get rid of" the car...don't. That's your choice. Nobody is forcing you.
    ^ some people may call this guy an asshole at times, but he isn't wrong very often -- Robert

    Comment


    • #3
      Ok I should have been more specific. If I don't have my foot ok the break it won't go any where until it its 4000rpm. Fluid is full and it does have a small slow leak but mentioned above its full


      Sent from my iPhone using Tapatalk

      Comment


      • #4
        Shift modules? Seem like you are starting out in the wrong gear and once you get going everything is fine?
        95 Beretta 3100 with 3400 intakes and TCE TB
        High flow cat and a Magnaflow muffler
        Grand Prix trans with 3.33FDR

        Comment


        • #5
          Originally posted by Schurkey View Post
          When was the last time you replaced the trans filter?

          Is the fluid burnt-looking, or still nicely red?
          ???
          ^ some people may call this guy an asshole at times, but he isn't wrong very often -- Robert

          Comment


          • #6
            When it was rebuilt. Also it's the 3.4 engine in the gp. It's nicely red


            Sent from my iPhone using Tapatalk

            Comment


            • #7
              Originally posted by aaron1428 View Post
              i have a 1991 Pontiac Grand Prix. it has about 350k on the clock with a rebuilt transmission.
              Originally posted by aaron1428 View Post
              When it was rebuilt. Also it's the 3.4 engine in the gp. It's nicely red
              WHEN WAS IT REBUILT??? You have 350K on the car, you've never said WHEN the trans was rebuilt. Could have been last month, or sixteen years ago.



              First Guess: You might as well tow this to a trans shop, maybe you'll get lucky and it's just a defective shift solenoid.
              ^ some people may call this guy an asshole at times, but he isn't wrong very often -- Robert

              Comment


              • #8
                Ya talked to my dad. Needs trans work. Has. 3.73 gear now. It was a special build built for bracket racing and it was rebuilt prob 9 years ago?


                Sent from my iPhone using Tapatalk

                Comment


                • #9
                  Nine years on a trans filter, for a vehicle used for racing?

                  Start there. See how much crap is in the trans pan, and if any of it looks like shrapnel. Read up on how to test shift solenoids.
                  ^ some people may call this guy an asshole at times, but he isn't wrong very often -- Robert

                  Comment


                  • #10
                    Wow!!! Stock transmissions should be serviced roughly every 15k. Flushed every 30k.
                    Built for racing, those intervals go down!


                    Poor tranny has served it's masters well!

                    Ben Lujin

                    Comment

                    Working...
                    X