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  1. #21

    Default Finally Got It!!!

    Well after many weeks of screwing with this thing, I finally pulled the transmission, bit the bullet and took it to a shop. I stood there as the guy worked like a well oiled machine and had the thing completely tore down within 5 minutes!! He started pulling pieces out of it, and all of sudden stopped and shook his head. In my experience never a good sign. Turns out there is a bushing in the overdrive planetary gears, and the planetary gears had seized for some reason spinning the bushing and welding itself to the planetary gears. He couldn't even get the gears apart to see what had actually caused them to seize. He picked up the phone to order the parts I was going to need. Shortly thereafter he tells me for the parts I need it's going to cost $200, great I thought. So then he looks at the transmission and turns to me and says $1725 to fix it!!!!!!! Oh well, I guess it's only money right?? So needless to say it's getting rebuilt and he said he would have it done for me to pickup tomorrow. I talked to a couple of different shops and this guy is the only one who really seemed like he knew what the heck he was doing, so I went with him. In the end after pulling the transfer case 3 times and tearing it apart and putting it back in, it was the transmission. Hopefully if anyone else ever comes across the same scenario, they can save themselves the time and hassle and cut straight to the chase!

  2. #22

    Default Same noise on a . HELP!!!!!!!!!!!!

    Have a 2001 suburban transmission rebuild 60K miles ago. Have same noise problem when I let go of accelerator on highway speeds seems to come right from the center of the car. Sounds like grinding/gears not meshing together. But it is a 2WD not a 4WD so I don't have a transfer case. Mechanic took the rear diff apart saw no problems. What up? Anyone know on a 2WD what would do this!

  3. #23
    Jr. Apprentice CoolAirVw's Avatar
    Join Date
    Nov 2008
    Kansas City, MO


    For future reference you can tell no move caused by transfer case vs no move caused by transmission by one simple test.....

    Will it hold park on a hill.

    Park is before the transfercase. So if the transfer case is causing no move you will have no park as well, meaning it will roll downhill.

    If trans is causing no move the park will 99% of the time still work.

  4. #24


    Mine was the transmission not the transfer case as I stated before, but it never made any noise at highway speed. It was always from a stop that it did it. If I could get it moving ever there was no problem at all with keeping it going. I would definitely say that it is something in the transmission and get it fixed sooner before later, as it will be a lot less money to fix before it totally eats apart the inside of the transmission. Not cheap to get it rebuilt, but cheaper than replacing the whole thing. Good luck!

  5. #25

    Default Same grinding noise and problem.

    I have had the exact same noise and problem. It has been happening on and off for 1.5 months, of daily driving all speeds (including highway). For past month happening once or twice a week. It seemed to "stick on" (always there) yesterday and today. I wondered if it was the transfer case, and I did have a service 4wd light on for the past 4 days. I also have had an DTC Engine Overspeed error code had in the past. I will have to look up that number and post later.

    So- last evening to this morning:
    Yesterday I cycled through 2HI, 4HI and 4LO, 4x4AUTO while stopped in my driveway. Only moving a few inches for engagement, if at all. Wondered if it had any affect on the sound. Apparently none, though I was able to cycle through all four ranges (4 LO has not worked before) for the first time since I bought the truck used in Jan.

    During this investigation, I heard/felt a clunk from the front diff I would say. I could hear the 4wd actuator moving (separately) at the transfer case, but nothing up front. It (t-case-based acutator) would engage, but not stay engaged. I was assuming the dash switch was bad, since the motor was working.

    When I heard the clunk, it was stuck in 4LO. It took slight rock or two, reverse, neutral, cycling ranges to get back into 2HI. Whew! That was it couldn't stand it anymore.

    I drained the transfer case and filled with t-case fluid (I have a NGP246-NP8). (Not Dexron III). Should have checked for filings, but I forgot after having such a hard time filing without spilling much.

    Proceeded to front diff. Drained. Found small shavings on the magnet. Some inside as well that reattached to the magnet when I reinserted the magnet after cleaning. Cleaned again and reinserted. Torqued to 24 ft lbs. (As opposed to t-fer case plugs which get 35.)

    Filled front diff with Lucas Hypoid gear oil. Old stuff that came out looked like the epoxy mixture or the two JB Weld tube contents, when combined. Like shiny gray toothpaste.

    Decided to wait on the rear for another day or two.

    Test drove and things seemed smooth, except the noise was still there after accelerating 50+ (louder).

    This morning while chauferring my wife to work gear noise got really loud, had to stab gas pedal repeatedly to make it go away. On the final try, I heard another slam/clunk and lost all drive power. Pulled over the side of the road. PRNDL shifting seemed to work, and rpms seemed to respond to accelerator, but shifting into D or R or N brought on even louder grear noise (loudest so far by far) so I shut it down and called tow truck.

    I will provide updates forthcoming.

    Also interesting reading form another forum. It's exactly what I have- at coast and decel: http://fordtruckworld.tenmagazines.c....asp?id=546971
    Last edited by rfrankli; 04-08-2009 at 04:49 PM.

  6. #26


    BTW- Mine WILL hold park on a hill. Trying to get you a video and audio link soon. The video shows no movement of the drive train (rear at least, where I had the camera pointed, at the time.

  7. #27


    Pipng in now.. What T case is it

    99 tahoe 2 dr. 4x4 7.4 4L80-e NP246, SAS, dana 60 hp, sterling 10.5 rear, gibson headers, and alot of tricks of the trade !!!!!!IF YOU'RE NOT CHEATING YOUR NOT TRYING!!!!!!!!

  8. #28


    That to me does sound like the transfer case. It was pretty easy to remove and rebuild, (I did it on mine waaay too many times thinking that I had done something wrong) although it was definitely a 2 person thing to put it back in! But on the other hand, it could be the transmission just as easy. But with the ease of rebuilding the transfer case it is something you could easily do by yourself, once you get into it it should be pretty obvious if it's the transfer case or not.

  9. #29
    Jr. Mechanic
    Join Date
    Jul 2008
    Bluegrass Country


    Just for grins and giggles, pull the diff cover off. Your probably going to find the problem there. Those rear ends are week and are known to strip the gears. I've replaced three rear ends on 97-03 in the last 2 months for basically the same symptoms your discribing.

  10. #30


    Quote Originally Posted by azdrtdog View Post
    Pipng in now.. What T case is it
    np246- same as yours.

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