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NP208 Transfer Case Problem, Any Ideas?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by ford_assassin, Nov 8, 2003.

  1. ford_assassin

    ford_assassin 1/2 ton status

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    Hey guys, I am new to K5 and this is my first post.

    This is about my '86 K5 Blazer 4x4 (full size). The truck is my daily driver so I gotta get it fixed pretty quick, but most of the shops around here want $500 just to find out the problem. If I had a few ideas about want the problem is I might just fix it myself.

    Anyway here's some background. I bought the truck 3 months ago, the tranny was rebuilt/beefed/updated/transgo shift kit installed. According to the shop receipt I have it was done 6000 miles ago, but over a year has past so the warranty is expired. Plus the tranny shop that did the work is 600 miles away.

    The truck and tranny have been working flawlessly since I bought it. Here's the problem. Today I was driving to work and after 10 mins of driving I start hearing a grinding noise over my radio. So, I start to make a turn onto a side street so I could pull over. As I slowed down to make the turn the tranny suddenly shifts down and when I complete the turn its like the tranny is no longer there when I went to apply the gas. I make a complete stop and try every gear, including reverse......nothing. Then when trying to place it in PARK it just grinds when trying to move the shifter. If the motor is off I can place the tranny in PARK, but the truck can still be pushed forward as if in neutral. I get it towed home and take my wife's Caprice to work.




    Now comes the weird part......


    I went outside after getting home from work (9 hours later) to check things out and to try and figure out if its the tranny or the transfer case.

    Well.....I wanted to hear the grinding noise again so I fired it up and put it in reverse thinking it wouldn't do anything. Much to my suprise it engauged reverse and everyother gear too. Plus the grind I got when putting in "PARK" is gone too.

    I want to be excited, but I am still worried about it. I drove it long enough to get to operating temp, and its shifting and driving like nothing ever happened. I am worried it will leave me pushing it again if I try the 20 min drive to work. Just to be sure, I checked the fluid level on the stick is nice and pink and doesn't smell burnt at all.

    While playing with the transfer case and trying to shift into "N" on the T-case shifter I get alot of grinding, I can't even make it into "4L". This leads me to believe the transfer case is to blame.

    This Blazer is my first 4x4, so this whole thing is new to me. I always thought that the transfer case was "direct drive", but I guess it turns out there is a pump and planetary gear set in it too. To the best of my knowing, the transfer case has never been rebuilt and the truck has at least 100K miles on it.

    I am totally stumped. I am not a tranny/transfer case guy by any means, so I need your help.


    Any and all suggestions are welcomed and thanked in advance.
     
  2. skratch

    skratch 1/2 ton status

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    Re: 208 Transfer Case Problem, Any Ideas?

    I'm definatly not an expert but it sound like the transfer case to me. I'd suggest draining it or at least checking the fluid to see how much metal content is there. That would as least get you going in the right direction.

    If I'm right it sounds like the trasfer slipped some how and so when the truck was stopped with the engine still running you could shift tranny gears but nothing was happening in the transfer case. When you went to put it in park the gears were still spinning in the tranny which caused the grinding. They won't stop unless their connected to the driveshafts and the brakes are holding them, then the only thing spining would be the torque converter.

    If it's the transfer case, they aren't too hard to swap and I'm sure you could find several in your area from others on the board, and most likely some help with the swap. I'm in Ohio so the three I have won't do you too much good.
     
  3. ford_assassin

    ford_assassin 1/2 ton status

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    Re: 208 Transfer Case Problem, Any Ideas?

    Thanks for the reply.

    A few people have IM me and suggested the problem might be the fork(s) or fork pads. Would that make sense?
     
  4. skratch

    skratch 1/2 ton status

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    Re: 208 Transfer Case Problem, Any Ideas?

    Yes, actually that makes sense. I had a similar problem with my first 208, then I blew the input slines out of it.
    It sound like it's shifting into neutral on it's own, which would most likely be a problem with the forks if I remember right from having mine rebuilt.
    There not too hard to deal with, I'd recommend rebuilding it own your own first (if you feel up to it) just to get the experience.

    Good luck and keep us informed on how it goes. /forums/images/graemlins/thumb.gif
     
  5. ford_assassin

    ford_assassin 1/2 ton status

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    Well I took a risk and drove it yesterday to work....no problems driving to work. Coming back was another story.

    Twice when the tranny shifted down for a light, then it would "fall out" of 2H. The only way I could get it to work again is by shutting the engine off, and moving the T-case shifter down to the "4L" position and then back to "2H". At least I figured out what to do when it does it, but it really sucks in traffic.

    I really hope its just the fork pads, I'll know later this week I guess.
     
  6. slimlynn1

    slimlynn1 1/2 ton status

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    Sounds like the fork pads to me. Mine does the same thing. I have another one ready to go in that I changed the pads on. It's not that hard to do.
     
  7. Steve_87K5

    Steve_87K5 1/2 ton status

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    I agree. My old 208 did the same thing. The fork pad is plastic and if the adjustment of the shifter is off a little, it rubs a little, until the pad is worn thru.

    Another symptom of the 208 being in "neutral" is a bad planetary. The planet gears are on small individual shafts on the carrier. If the oil (ATF in a 208) level gets low enough, these gears overheat in low range, and can seize on their shafts, and become dislodged from the carrier.
    The 208 will have zero engagement, and the truck will not move in hi or lo.

    Get thee a big socket so you can check the
    oil level. IIRC its 32 mm.
     
  8. ford_assassin

    ford_assassin 1/2 ton status

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    Well guys, I found a decent shop that a friend recommended. It was a 45 min drive to get to him, but I think it was worth it.

    It turns out that that there were more than just one problem. The pads on the fork weren't the problem....because the fork was eaten up. Not only that but the front input shaft carrier bearing assembley was toast too. He thinks that my MPG might improve with that being fixed since with the extra resistance was kinda working against itself.

    The guy is totally cool though. He originally quoted me $150 part AND labor to yank the T-Case and replace the pads. He got the shifter fork from the dealer ($80) and the whole front bearing assembley from a donor NP208C that cracked its case. He is only charging $40 for it. He is not charging me any extra labor for the extra work. So I am only looking at $270 and I am back in business.

    It gets better. Because the dealer was slow in delivering the fork, he didn't get it finished today. So, he is coming in tommorrow to finish it (Saturday) so I can have it for work on Sunday.

    To say the least I am VERY impressed with this man. I am into drag racing and I am always looking for a decent and trustworthy builder for my Th400's....I think I found him.
     
  9. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    [ QUOTE ]
    Well guys, I found a decent shop that a friend recommended. It was a 45 min drive to get to him, but I think it was worth it.

    It turns out that that there were more than just one problem. The pads on the fork weren't the problem....because the fork was eaten up. Not only that but the front input shaft carrier bearing assembley was toast too. He thinks that my MPG might improve with that being fixed since with the extra resistance was kinda working against itself.

    The guy is totally cool though. He originally quoted me $150 part AND labor to yank the T-Case and replace the pads. He got the shifter fork from the dealer ($80) and the whole front bearing assembley from a donor NP208C that cracked its case. He is only charging $40 for it. He is not charging me any extra labor for the extra work. So I am only looking at $270 and I am back in business.

    It gets better. Because the dealer was slow in delivering the fork, he didn't get it finished today. So, he is coming in tommorrow to finish it (Saturday) so I can have it for work on Sunday.

    To say the least I am VERY impressed with this man. I am into drag racing and I am always looking for a decent and trustworthy builder....I think I found him.

    [/ QUOTE ]

    What shop did you take it to?
     
  10. ford_assassin

    ford_assassin 1/2 ton status

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    Automatic Transmission Specialists
    Visalia, Ca.
    (559) 732-3320

    /forums/images/graemlins/thumb.gif
     
  11. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    [ QUOTE ]
    Automatic Transmission Specialists
    Visalia, Ca.
    (559) 732-3320

    /forums/images/graemlins/thumb.gif

    [/ QUOTE ]

    /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif
     

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