Truck won't shift out of park!?

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by AgKyle2010, Dec 10, 2011.

  1. AgKyle2010

    AgKyle2010 New Member

    I have a 1999 Chevy Silverado 4x4 Single Cab Truck that I've been having problems with for a few weeks now. I first had problems with the truck having a hard time getting up to speed. I couldn't get on it too hard or the RPMs would max out and this loud clacking/grinding noise would occur. So I had to give it a little gas and just give it time to get up to about 60mph on the highway. Once I got up to 70mph, it was really hard for me to keep it at 70 mph. It kept wanting to drop back down to 60mph and then kick into a lower gear to get back up to speed. The RPMs were constantly going from 2000-3000 RPMs because of this. I first originally thought the engine wasn't getting enough fuel so I replaced the fuel filter (which I found to be clogged with a lot of crud). This seemed to have fixed the problem until recently I started having the same problems again.

    Not only is it doing the same thing as before but I now have another problem. I got into my truck today, applied the brake to shift out of park, put the truck into reverse, and my truck immediately started accelerating before I even took my foot off the brake! The RPMs went up to about 2000 and the speedometer was at about 15mph-20mph! I then immediately put the truck back into park and the RPMs and speedometer slowly dropped back down along with a loud clacking/grinding noise. It's like my truck is telling me I'm in drive or reverse, my engine thinks I'm in drive or reverse, but my transmission is NOT in drive or reverse. I have no idea what could be wrong. Any help would be greatly appreciated.
  2. Trask215

    Trask215 Rockstar 100 Posts

    Sounds to me like one of your computers is seriously outta wack, probably your powertrain control module. I'm not a mechanic but that's my best guess. I would scour a junkyard for one or maybe take to a dealer, your truck is not safe to drive. Good luck, hope you don't gotta spend a ton of money......
  3. AgKyle2010

    AgKyle2010 New Member

    Do you think maybe it would be a bad throttle position sensor or a broken transmission shift cable?
  4. TRPLXL2

    TRPLXL2 Epic Member 5+ Years 1000 Posts

    TPS wouldn't do what your saying the truck is doing, I had a broken shift cable in my S10 and It wouldn't stay or go into park. There is a small clip that holds the cable onto the side of the transmission, there is a rubber boot over the end of the cable. I would crawl underneath it and pull the boot back and inspect the cable and that clip, also there is a shift interlock solenoid that tells the VSS on the side of the transmission which gear your in and tells the computer the appropriate gear.
  5. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    I had a friend with the same truck and same kinda issue. The rearend was going out. So when he put it in gear the trans spun the driveshaft like it was not connected to anything. So the rpms and mph went up. It made all kinds of noise. He could drive it but the rpms jumped all over as the rear end caught and slipped, not a fun ride with him. He eventually jacked the rear up, with both tires off the ground, put it in gear and set the parking brake. The driveshaft spun and then the rear end caught, spun then caught. He put a new rear end in and it solved his issue.
  6. AgKyle2010

    AgKyle2010 New Member

    I found out what my latest problem was with my truck not shifting into gear. Y'all aren't going to believe this but someone stole my f****n driveshaft! Can you believe that?! I live at an apartment complex with the truck part right outside my window! I just cannot believe this...
  7. johnb9173

    johnb9173 New Member

    your right i don't believe you
  8. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    x2 on not believing that someone stole your driveshaft!
  9. AgKyle2010

    AgKyle2010 New Member

    Lol this is too stupid to just make up. All I know is that my driveshaft is gone and I sure as hell didn't take it off...
  10. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

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