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wiper transmissions

Discussion in 'Chevy Trucks' started by blue98gmc, Oct 16, 2006.

  1. blue98gmc

    blue98gmc Junior Member
    Messages: 7

    Truck= 1998 GMC 2500 Club Coupe 4WD. My wipers are making a screeching mechanical sound, not rubber on glass, but metal on metal. I have a lot of end-play on the posts the arms attach to, and I've been told I need new wiper transmissions. My question is, how the **** do I get the plastic cowl piece off to get at the linkages underneath? I see a screw at each end, but it appears to only hold on a sparate short piece. The center section (the one the posts come through) remains firmly in place. Anyone have any insight into how to get this apart?


  2. Offroadz71

    Offroadz71 Member
    Messages: 40

    Wiper intalls

    Just did this a few weeks ago, on my 98. Your in good hands! Before you go too far remember to take a piece of scotch tape and mark where your blades come to rest on your windshield, if you mess up later with the rotor arms you will save some time.
    First thing is to make sure you get the Wiper motor with the Sealed case. Reason why is because you won't have to return the motor if you mess up the timing. I got mine from NAPA, for $60.00 and Core Replacement refund. It's an all-in-one unit which is newer than the old ones, with less hassle of lining it up correctly. Second on the wiper cowl you will have two screws, one on the passenger and drivers side to remove the 4"x4" cowl piece. After that you need a small step ladder and remove 3 or 4 screws on the long piece of cowl. Once you have all the screws removed and the WIPER blade ARMS removed, disconnect the washer-fluid hose. BE VERY CAREFUL NOT TO PINCH THE COWL WITH THE HOOD AND CRACK YOUR COWL. Then with the hood about 3/4 open you can move the cowl up the windshield a little it to give clearance up front. As you Release the hood to Full open and angle your way out. Take note of were the steel arm is in relation to the motor for purposes done later when you need to take this arm off. After that take a Yellow or White crayon and make a mark on the swivel arms that connect the long rods to the actual servo unit that operates the wipers, If you don't have a crayon handy I always use Quick dry WITE-OUT. Then you need to loosen, (do not pull all the way out) the nuts that hold the ball joints to the servo from the motor. This will make the Motor free of any operation of the wipers. Then Simply remove the motor. Using a large sized Crescent wrench, clamp the crescent wrench around the ob-long (or arm) piece that is perpendicular to the shaft from the motor. I sandwiched that piece between the wrench's arms for better leverage and to avoid slipping. Then using the appropriate wrench loosen the nut on the shaft so that the arm can come off and be placed on the the motor. If possible mark your location of the arm with the motor shaft, and direction. I am not sure if this is really required but I thought of being safe than sorry. Once all this is done, BEFORE you attach that steel plate arm to the shaft with the wrench, TAKE the motor and place back into position of the original and screw back in. THREE SCREWS. Plug the wire back in and run your blades to make sure the motor is set in its default location. After that remove the motor and wrench the motor arm back onto the shaft of the motor. You will not be able to Wrench this arm tight when it has been screwed to the fire wall. After that its pretty simple, what needs to be done. Just be sure and run your wiper blades to make sure that they are running properly and positioned correctly before you put the cowl back on. TIME: about an Hour. Handy tool, TABLE TOP VICE CLAMP. Let me know how it goes. It's Pretty easy.
    Last edited: Oct 18, 2006
  3. blue98gmc

    blue98gmc Junior Member
    Messages: 7

    Thanks! I don't think I need to go as deep as the motor, only the assembly at the base of the passenger side post the wiper arm mounts to. I'll know more after I get in there.

    I appreciate the detailed cowl removal procedure, that's just what I was after. I'll definitely let you know how I make out.