Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Specified idler preload on np205??

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by fortcollinsram, Mar 28, 2007.

  1. fortcollinsram

    fortcollinsram 1/2 ton status

    Joined:
    Nov 8, 2001
    Posts:
    2,261
    Likes Received:
    0
    Location:
    Fort Collins, CO
    I am hunting down a wicked vibration that I have traced to my 205... What is the specified idler bearing preload/endplay on 205's?


    Thanks
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,980
    Likes Received:
    189
    Location:
    Roy WA
    I can't help you out right now, hope you don't mind me posing a question to you.

    Do you have the 205 apart or is it still in the truck.

    If it's in the truck, any chance you could look at the rear output with the engine running, trans/t-case in neutral, and see if you get any vertical movement?

    I should be able to check my '91 manual tomorrow for any assembly specs GM may have used for you, if you like.
     
  3. fortcollinsram

    fortcollinsram 1/2 ton status

    Joined:
    Nov 8, 2001
    Posts:
    2,261
    Likes Received:
    0
    Location:
    Fort Collins, CO
    yeah there rear output has a little movement...enough to concern me at least. The t-case is still in the truck but I am gonna take it out and pull it apart and look at everything and reseal it. If you could get the idler end-play spec. that would be awesome...

    Chris
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,980
    Likes Received:
    189
    Location:
    Roy WA
    Unfortunately it looks like by 1991 GM was already just replacing parts.

    Only numbers in the manual are (all ft lb numbers):
    Adapter to trans bolts (auto trans) 24
    Adapter to t-case bolts (auto) 24
    Mounting to Transfer case bolts (auto) 24
    T-case to transmission bolts (manual) 24
    Propeller shaft yoke nut (NP241) 110
    Propeller shaft yoke nut (NP205) 150
    Drain plugs 35
    Pump retainer housing bolts (NP241) 30
    Shift lever pivot bolts (205) 100
    T-case adapter mounting bolts 35
    T-case adapter mounting nuts 33

    I think an earlier manual might be a better bet, if someone is willing.
     
  5. BadBob

    BadBob 1/2 ton status

    Joined:
    Aug 14, 2005
    Posts:
    158
    Likes Received:
    0
    Location:
    Lyndon, KS
    It's not in my 74, 77, or 82 manuals either.
     
  6. tarussell

    tarussell 1/2 ton status

    Joined:
    Dec 28, 2002
    Posts:
    1,354
    Likes Received:
    0
    Location:
    Bagdad , FL
    I don't have any written spec's either but I can tall Ya' that you want to get a slight pre-load on the two opposed tappered roller bearings that are in the idler gear section. Try and get a similar pre-load as you would doing a set of full floating wheel bearings. No binding what so ever but no slack with a slight pre-load. Don't forget to keep all parts thouroughly lubed up while setting the pre-load.

    Tom
     
  7. MEK5

    MEK5 1/2 ton status

    Joined:
    Jan 21, 2006
    Posts:
    244
    Likes Received:
    0
    Location:
    Maine
    The specs. are .000-.002 endplay on those bearings,I always shoot for .000 with new bearings because they will loosen up.Your not really putting any preload on them just NO endplay but gear spins freely by hand.If you get them too tight your transfer will growl and run hot.
    You need to get the shim setup fiqured out before you put it back together,most times you can use the original shimming but not always.
    If your buying just the idler bearings and not a complete kit get Timken bearings/races
     

Share This Page