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.

transfer case or rearend??

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Wallyb, Jan 15, 2001.

  1. Wallyb

    Wallyb Registered Member

    Joined:
    Jan 15, 2001
    Posts:
    24
    Likes Received:
    0
    Location:
    Southwest Minnesota
    I need some input, please. My problem is when I'm slowing down to a stop I can hear a clunk sound. At first I thought it came from the rearend, but then the next time I thought it came from the transfer case?? There is no high wirling noise coming from the rearend, so would that mean it's my t-case?? Please, help me. Imput much appreciated!!

    P.S. I replace the u-joints already, but didn't fix the problem!

    <P ID="edit"><FONT SIZE=-1>Edited by Wallyb on 01/15/01 04:51 PM (server time).</FONT></P>
     
  2. mudddog91

    mudddog91 1/2 ton status

    Joined:
    Dec 28, 2000
    Posts:
    471
    Likes Received:
    0
    Location:
    north carolina
    WHAT ARE YOU WORKING ON?
     
  3. mudhog

    mudhog THEGAME Staff Member Super Moderator

    Joined:
    Nov 6, 2000
    Posts:
    17,899
    Likes Received:
    2
    Location:
    portland oregon
    have you checked the tranny mount?

    s.smith 77blazer lookin 4 mud
     
  4. Wallyb

    Wallyb Registered Member

    Joined:
    Jan 15, 2001
    Posts:
    24
    Likes Received:
    0
    Location:
    Southwest Minnesota
    I'm working on my 1990 Full size blazer, 350 TBI, 700r4 tranny, with a 241 transfer case, 10 bolt 3:73 gears. The tranny was rebuilt about a year ago.
     
  5. DMK

    DMK 1/2 ton status

    Joined:
    Feb 20, 2000
    Posts:
    757
    Likes Received:
    0
    Location:
    CINCINNATI, OH
    My 89 blazer did the cluning noise on stopping for a while. Des yours also do it when leaving a light? Mine did. There was no whirring noise, at least not right away. Rearend did go out. How many miles do you have?
     
  6. DMK

    DMK 1/2 ton status

    Joined:
    Feb 20, 2000
    Posts:
    757
    Likes Received:
    0
    Location:
    CINCINNATI, OH
    My 89 blazer did the clunking noise on stopping for a while. Does yours also do it when leaving a light? Mine did. There was no whirring noise, at least not right away. Rearend did go out. How many miles do you have?
     
  7. BillyBob

    BillyBob 1/2 ton status

    Joined:
    Feb 23, 2000
    Posts:
    557
    Likes Received:
    1
    Location:
    Dumont, NJ
    Mine does the clunking noise when I'm stopping at a light. I believe it's my transmission shifting into the granny gear, since that's the only time a 700R will shift to that gear normally. In my case, it's usually a thunk followed by a major slowdown.. kinda like stopping by downshifting without using the brakes (I think that's called compression braking). In any case, I dunno if it's anything to worry about. But if it's really bugging you, get it checked out.
    [​IMG]

    <A target="_blank" HREF=http://billybob.coloradok5.com>http://billybob.coloradok5.com</A>
    It's all fun 'n games, till someone gets stuck.
     
  8. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,068
    Likes Received:
    479
    Location:
    Grand Rapids area
    The clunk may be from the transmission. Many 700's from the mid 80's had a 2nd to 1st downshift clunk. When you are slowing down, downshift manually and see if that triggers the thunk. It may also prevent it. Many 700's received a "fix" for the thunk from the dealers, but then they usually thunked when the shifter was left in 3, but not when it was left in D. That is what mine does, anyway. Has it done this ever since the tranny was rebuilt? Usually the clunk from a rearend occurs when you get on or let off the gas, or when you drop it into gear. A worn rear end can clunk from loose spiders or R&P without making a whining noise. The whining usually comes from bad bearings or a chewed up R&P.

    <font color=blue>Powered by a Goodwrench 4-bolt longblock [​IMG]
    240hp...for now.</font color=blue>
     
  9. Wallyb

    Wallyb Registered Member

    Joined:
    Jan 15, 2001
    Posts:
    24
    Likes Received:
    0
    Location:
    Southwest Minnesota
    the clunk only comes when I'm slowing down to a stop or to turn. Also, when I have it in od instead of D, then you don't hear it. It's got to be the rearend right??

    Thanks everyone!
     
  10. PattBlue

    PattBlue Registered Member

    Joined:
    May 3, 2000
    Posts:
    82
    Likes Received:
    0
    Location:
    N.W. Pennsylvania
    I asked this same question about a year ago. I have the same K5..with the same everything. Mine has a bout 82,000 miles now. Anyway When I came to a stop and then let off the brakes I could hear and FEEL a CLUCK, THUNK..whatever you call it. I asked numerous people, I was worried cause it sounded like the body was going to fall off. Well I started with the U-Joints then I did the rear brakes and finally asked the GM Dealer Mechanics. They said there is a GM service bulletin for this. They want you to pull the drive-shaft and put GREASE inside the front yoke. I guess it hits the transfercase lip and CLUNK!! Of course GM calls it "SPECIAL PURPOSE LUBRICANT" but its grease. It stops it for a bout 4 months and it starts again. Hope this helps..good luck!!
     
  11. Wallyb

    Wallyb Registered Member

    Joined:
    Jan 15, 2001
    Posts:
    24
    Likes Received:
    0
    Location:
    Southwest Minnesota
    thanks for the responses, good info! Lubing the yoke probably helps the clunking noise, but I hear it and feel it in the rear only when I'm slowing down to a stop, not when I'm stopped already. I hear it when it downshifts right before stopping. Why when in OD it doesn't do it?? any ideas??
     
  12. RADMAN

    RADMAN Registered Member

    Joined:
    Feb 23, 2000
    Posts:
    12
    Likes Received:
    0
    Location:
    TEXAS
    Mine does the same damn thing and it's making me crazy. It doesn't do it at every stop. I've got a 89' Jimmy with 4" lift. I had a drive line shop put a new longer driveline and heavy duty u-joints in it so it's running back in a stock position on the output shaft. As soon as I let pressure off of the brakes, it pops or clunks like the trans.is slipping or shifting. Why it's not down shifting untill then, I don't know. The only thing that's not new is the 700R, but it has had some work due to the overdrive kicking in and out when against a 5mph wind. Go to www.nhtsa.dot.gov/cars/problems/tsb/servicemmy1.cfm and you can investigate all related recalls and problems with any vehicle. Anyone else had the same problem? Let us know, maybe we can figure this mystery out.

    TAKE HER TOP OFF, AND ROLL HER IN THE MUD!!!!
    89'JIMMY
     
  13. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,068
    Likes Received:
    479
    Location:
    Grand Rapids area
    Wallaby, er, Wallyb, (j/k)

    You have just answered your own question. When you put the tranny in OD, there is no problem, but when you put it in D (3rd), there is a clunk. The only thing different between the two scenarios is the transmission and that is where it is coming from. It is just like I posted above. The clunk occurs when it downshifts into 1st gear, which only happens when you are slowing down to a stop or to turn a corner (unless you have modified your tranny, but that's a whole different topic). I believe that there is a fix for it. It would have to involve some modification to either the valve body or the seperator plate.

    From what I've heard, it isn't hurting anything too much, but I don't know that to be true. To get around it, you can always drive around in OD.

    <font color=blue>Powered by a Goodwrench 4-bolt longblock [​IMG]
    240hp...for now.</font color=blue>
     

Share This Page