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.

A weak link? 4spd.-205 Coupler sleeve

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by mountainexplorer, Jun 10, 2002.

  1. mountainexplorer

    mountainexplorer 1/2 ton status

    Joined:
    Nov 14, 2001
    Posts:
    4,903
    Likes Received:
    0
    Location:
    Spokane, Wa./Ione, Wa
    My friend has broken (shattered) the 10 spline coupler sleeve that goes between his SM465 tranny and 205 T-case twice. He broke it first in March, the truck sat, then replaced it in late May, only to have the brand new just-installed sleeve shatter 3 days after.
    I would think a U-joint or something else would break before shattering a second coupler sleeve.

    What's the deal? Could it just be his "curse" that we say he has? Or is it possible the new sleeve was weak or defective?
     
  2. m j

    m j 1/2 ton status

    Joined:
    Dec 28, 2001
    Posts:
    4,606
    Likes Received:
    0
    usually the splines on the tranny are worn.
    how did/do they look on his tranny?
     
  3. mountainexplorer

    mountainexplorer 1/2 ton status

    Joined:
    Nov 14, 2001
    Posts:
    4,903
    Likes Received:
    0
    Location:
    Spokane, Wa./Ione, Wa
    Well, everything checked out when they replaced the coupler sleeve last time. Both output shaft of the tranny and input shaft of the transfer were in excellent shape. Just both times, the sleeve just literally shattered into pieces.
     
  4. m j

    m j 1/2 ton status

    Joined:
    Dec 28, 2001
    Posts:
    4,606
    Likes Received:
    0
    strange,
    on Pirates right now is some pics of the output shaft broken.
    bet that guy would have prefered the coupler to go.
     
  5. Diesel Dan

    Diesel Dan 1/2 ton status

    Joined:
    Feb 27, 2002
    Posts:
    798
    Likes Received:
    0
    Location:
    Warren, Ohio
    I broke two of those as well. 1 year apart, same mud hole. First year was running 40s, second year 44s. Only drivetrain part I actually broke, mine was from dumping the clutch at 4,000rpm+ while the tires had good traction. My new sleeve was less than 1 yr old so the dealer warrantied it.
     
  6. mountainexplorer

    mountainexplorer 1/2 ton status

    Joined:
    Nov 14, 2001
    Posts:
    4,903
    Likes Received:
    0
    Location:
    Spokane, Wa./Ione, Wa
    We're hoping the latest sleeve will be under warantee as well (its only been 2 weeks). The truck he's running has 39.5" Boggers and its a 1-ton Crew Cab, so it's pretty heavy.

    The 1st time he broke it he was on flat ground with the tires turned fairly hard to the right in 4wd, he went to take off foreward and "clunk", that was it.

    The 2nd time he was driving in one of the two mud pits we had at my place for Memorial Day Weekend. It bogged down, so he put it in reverse, spun all the tires and backed up 15 feet, took off foreward and went about 25 feet, then went to put it in reverse. His RPMs werent very high at all, but on the video, you see he barely lets the clutch out, the tires just barely start to move back, then "clunk".

    Pictures off the video are here: http://community.webshots.com/album/39887808jxzxFP
    at the bottom showing the pit he was in and still shots just seconds before he broke it.
     
  7. Blazer1970

    Blazer1970 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,600
    Likes Received:
    0
    Location:
    Old Mission, MI
    Now you know why they changed it to 32 spline. It only took them about 15 years!
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    I'm kinda wondering if GM didn't make these "sacrificial" and thus "weaker" than the input/output shafts, so that *it* wears out/breaks (hopefully) rather than the trans pieces. Would get expensive to keep breaking them though!
     
  9. m j

    m j 1/2 ton status

    Joined:
    Dec 28, 2001
    Posts:
    4,606
    Likes Received:
    0
    I have a coupler 465s with worn mainshafts, wish they made the coupler softer
     
  10. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    I'm going to have to check mine when I pull them, as I've got some slop which seems inherent in the 465/205, and I have a feling its either the splines on the shafts, or the coupler. I certainly hope its the coupler.

    Odd that in some trannies/t-cases the shaft splines are fine, and yet in other cases, the shaft splines are worn...

    Yet another reason someone needs to be making these things aftermarket.
     
  11. m j

    m j 1/2 ton status

    Joined:
    Dec 28, 2001
    Posts:
    4,606
    Likes Received:
    0
    one theory is lack of lube in the coupler.
    give it a shot af grease on reassembly, cant hurt?
     
  12. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    Yeah thats true, a little grease never hurt, good point.
     
  13. 70~K5

    70~K5 1/2 ton status

    Joined:
    Apr 13, 2002
    Posts:
    2,032
    Likes Received:
    0
    Location:
    sillycon valley
    My new PTO/ pump for my dump truck in the instructions said to lube the splines on the contection with antisieze once a year or more often.
     
  14. RedDwarf

    RedDwarf 1/2 ton status

    Joined:
    May 9, 2001
    Posts:
    816
    Likes Received:
    0
    Location:
    North Central Florida
    Cool I'll have to do that to mine.
     

Share This Page