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NP208 Tailshaft seal Replacement???

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 78Blazer, Aug 9, 2002.

  1. 78Blazer

    78Blazer 1/2 ton status

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    I have to replae the tailshaft seal in my np208. I havent actually looked at it to see what I have to do yet. Im hopeing it is just as easy as pulling the old one and putting the new one in? Am I right?
     
  2. outlaw612

    outlaw612 1/2 ton status

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    Yep, just pull the old one out and tap the new one in.
     
  3. 95 Silverado

    95 Silverado 1/2 ton status

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    a word of advice, be sure the seal is actually what's leaking before you change it. I've had experience with 208's and 241's with slip yoke style tailshafts, there is a plug in the end of the tailshaft yoke which plugs the end of the splined tube of the yoke, this plug will leak oil out of the transfer case in behind the u-joint, I've seen several posts where guys change the seal only to have it continue to leak. if the seal is leaking the oil will usually be running down from the seal over the transfer case, when the yoke plug leaks it tends to spray the bottom of the cab floor with oil from the spinning driveshaft above the u-joint, it will also drip from the yoke when the vehicle is sitting and leave a spot on the ground. take a good look and see where the oil is leaking from before assuming it's the seal, it may save you some aggravation later.
     
  4. 78Blazer

    78Blazer 1/2 ton status

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    Well actually the leak looks more as you are describeing, The bottom of the truk has fluid all over it and it drips from the ujoint. But I am not sure I quite get what you are saying is the cause of this? What do I need to change look for etc... I have to drive this thing 120 miles tommorrow and would like to have it fixed before.

    Thanks
     
  5. bajaviking

    bajaviking 1/2 ton status

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    I know what you mean, I changed my damn seal twice before i found out it was the slip yoke that was leaking. By the way, do you know any easy fix for this or do I need to pull the plug and reseal it.
     
  6. 95 Silverado

    95 Silverado 1/2 ton status

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    with the drive shaft removed from the truck, clean the area around the u-joint on the front slip yoke, behind the u-joint you will find a flat steel plug which is driven in place to seal the end of the driveshaft yoke. the fluid leaks out around this plug. I've been told you can clean this with carb or brake cleaner around the plug edge and seal it with RTV. I have always removed the U-joint, removed the plug, cleaned both surfaces and used a sealer in the mounting groove and reinstalled the plug. if you don't distort it when you pop it out it can be reused. the RTV method may work but I don't know for how long.
     
  7. bigjbear

    bigjbear 1 ton status Staff Member Moderator

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    If you can't get the plug to seal a new Spicer slip yoke is less than $20. If you pull the shaft like 95 was saying you may want to replace the tailshaft seal while its out anyway. Also inspect the u-joint and slipyoke for ware.
     

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