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flywheel/starter problem

Discussion in 'Chevy Trucks' started by joedirty, Jan 30, 2003.

  1. joedirty

    joedirty Junior Member
    Messages: 1

    I have a '77 GMC 1/2 ton-350/automatic with some teeth missing from the flywheel.This creates a starter engaging problem (I'm amazed at the number of times the flywheel stops in the "wrong" spot).
    What are my options and does the flywheel have a removeable starter ring or is it one piece?thanks in advance,jd
  2. Wesley's Lawn

    Wesley's Lawn Senior Member
    Messages: 394

    I think you are pretty much going to have to drop the tranny to replace the flywheel.
  3. Pelican

    Pelican 2000 Club Member
    Messages: 2,075

    Welcome to Plowsite, joedirty. (I'm not even going to ask):drinkup:

    What's a Texan doin' on a snowplow site?:confused:

    To your question:

    If you had a flywheel, the starter gear would be replaceable, but you state the truck's an automatic. That means you've got a flex-plate that bolts to the torque converter and it's a one piece unit. They aren't that expensive and the job isn't all that hard if you've got the proper equipment.

    You should determine what caused the teeth to break while making the repairs to be sure it won't reoccur.
  4. hyperpack

    hyperpack Senior Member
    Messages: 108

    Toothless Gear

    A few years ago I had the same problem with my old Dodge, Didn't want to take flywheel off to replace ring gear, Figured it was already broke so any shortcuts I tried wouldn't hurt anything.
    I removed the pan off the belhousing cleaned up where the three teeth were worn off and carefully welded them back trimmed them up with a die grinder and file, It only took an hour and has been working for years still sounds great. If you have a welder you could get some good 3/32 welding rod that will weld overhead and give it try, Just be sure you get the ground wire on the gear near where you are welding.
  5. plowking35

    plowking35 2000 Club Member
    from SE CT
    Messages: 2,923

    As a matter of clarification, the flex plate bolts to the cranck shaft, and has the starter ring gear welded to out side of the flex plate. The tranny is then slid into place, and the T/C is bolted to the flex plate making that connection. A flywheel is only used in manual trannies.
    The welding idea may work, you have nothing to lose.
  6. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Id just do the job right,get it over with.The new flexplates are about 30 bucks,definetely replace the starter bendix drive,or the entire starter at this time.It needs to be properly shimmed as well.Like Pelican said,find out what casued it ,you may have been running around with a bad starter that ate the teeth,advanced ignition timing,or a slow leaking head gasket /cracked head can cause it as well.Im sure you'd know if the head gasket was leaking by the miss when it starts,and white smoke/loss of coolant.
  7. Ohiosnow

    Ohiosnow Senior Member
    from Ohio
    Messages: 415


    Just to let you know don't have to drop the trany to change the flex-plate. You just have to separate the engine & trany about 1" or 2" :waving: I've done it many times ;) ( on different cars & trucks) but do check starter & shim as needed.

    CARDOCTOR PlowSite.com Addict
    Messages: 1,312

    dont drop the trans removeflexplate bolts disconnect the driveshafts unbolt trans mount remove trans to block bolts replace 2 with long bolts sometimes i use allthread slid the trans back far enough to remove flex plate to crank bolts.they sell a flywheel tool to make turning the flexplate easier

  9. Wesley's Lawn

    Wesley's Lawn Senior Member
    Messages: 394

    Jezze where the heck was my mind on that one I never though bout it that way, Do you guys know if that will work for the tranny seal behind the flywheel?
  10. wyldman

    wyldman Member
    Messages: 3,265

    If you talling about a rear main seal,then yes,it could be done,but very difficult to get the seal in straight without folding the lip over or damaging the seal.It would also be very difficult to properly torque the flexplate bolts.

    The front convertor seal on the tranny requires complete removal,or far enough back on a jack to get the convertor out.
  11. Ohiosnow

    Ohiosnow Senior Member
    from Ohio
    Messages: 415



    "It would also be very difficult to properly torque the flexplate bolts."

    Why ???? It's never been a problem for me.:waving: with my tork-wrench.