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.

Clunking noise when accelerating...HELP!

Discussion in 'The Garage' started by jfewell, Aug 6, 2005.

  1. jfewell

    jfewell Newbie

    Joined:
    Aug 6, 2005
    Posts:
    1
    Likes Received:
    0
    Location:
    Northern California
    We just bought our Suburban today. When we pull up to a stop sign or stop at a red light then accelerate when it is time to drive, the vehicle makes a sort of clunking noise. So, accelerate, clunk, clunk, drive. :confused:
    It only happens after braking at a stop then taking off. If I were to start the car right now and drive away it would not make the noise. Only during driving after I have applied the brake then accelerated from a stop.
    Does anyone have a clue what that could be?

    It is driving my husband nuts! :doah:

    Thanks a bunch

    Jerod & Heather
     
  2. 85mudblazin

    85mudblazin 1/2 ton status

    Joined:
    Mar 26, 2004
    Posts:
    3,951
    Likes Received:
    0
    Location:
    Austin,TX
    Check your motor mounts, they may be old causing the whole drivetrain to rock and make the t-case hit the floor.
    Other then that it might be a u-joint in the driveshaft going bad.
     
  3. down4thakrown

    down4thakrown 1/2 ton status Premium Member GMOTM Winner

    Joined:
    Aug 5, 2003
    Posts:
    1,760
    Likes Received:
    75
    Location:
    flagstaff,az
    try checking the u joints. go under it and try to shake, spin, and move the drive shaft differant directions at both ends to see if there is any play in the joints.
     
  4. tomseviltwin

    tomseviltwin 1/2 ton status

    Joined:
    Dec 23, 2001
    Posts:
    2,065
    Likes Received:
    0
    Location:
    Utah
    Could be a bad flexplate. remove inspection cover on tranny and see if there is any "wobble" in the torque converter as it idles. It it is you need a new fp.
     
  5. big jimmy 91

    big jimmy 91 1/2 ton status

    Joined:
    Feb 21, 2004
    Posts:
    639
    Likes Received:
    0
    Location:
    Northwestern Ontario Canada
    My Jimmy does the same thing and it is the transfer case hitting the floor pan
    It is just worn out mounts I guess :dunno:
     
  6. jfewell

    jfewell Newbie

    Joined:
    Aug 6, 2005
    Posts:
    1
    Likes Received:
    0
    Location:
    Northern California
    Thank you all

    for such quick replies. :laugh: My husband is going to check out everything you all replied with.

    Appreciate it very much!!! :bow:

    Heather & Jerod
     
  7. perp

    perp 1/2 ton status

    Joined:
    Jul 14, 2005
    Posts:
    569
    Likes Received:
    0
    Location:
    Chandler AZ
    a bad carrier bearing in a 2peice drive line will do exactly that. if you have a 2 pc, that is. if you do, have the hubby lay on the ground next to the truck, and with foot HEAVY on brake, shift from drive to reverse and back a few times while running. you will see the driveline jump up an down if the Carrier is bad
     
  8. kit

    kit Registered Member

    Joined:
    Nov 30, 2005
    Posts:
    18
    Likes Received:
    0
    Location:
    Ann Arbor
    Rotational clunking?

    I've just gotten a fullsize 89 blazer that has, on occasion, a rotational clunking. At low speeds there is sometimes a clunking that seems related to speed. As I increase speed so does the clunking, until, at about 15 or 20 mph, it stops.
    I just havent a clue. My joints all seem fine and having opened the rear differential I know that it's an open differential with all of it's teeth intact.
    Is yours like that? If not, have you any thoughts?
    Thanks
     
  9. BIG*RED

    BIG*RED 1/2 ton status

    Joined:
    Mar 14, 2003
    Posts:
    1,094
    Likes Received:
    0

    Just another thought..how are your rear breaks? i assume they are still drum brakes..they could be worn, or the hardware worn, and they are hanging up, and the clunk is them "poping" back in place...Also i have seen a truck where the backing plates were so worn, (the brake shoes, wore a huge grove in them) and as the brakes were appiled and released, the shoes would pop in and out of these grooves..
    Just a thought
     
  10. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,577
    Likes Received:
    943
    Location:
    Massachussetts
    check and see

    Make sure its not in 4wd,or that the hubs are locked, if they are manual hubs..the CV joint on the front driveshaft often "clunks" when it or the splines on the slip yoke attatched to it get sloppy..my old K20 sounded like a bulldozer with worn tracks when taking off and backing up in 4wd thanks to worn splines on the front driveshaft..when its in 2wd with the hubs "unlocked",the noise should dissapear or lessen if its due to that..

    Some years had a "full time 4wd" transfer case,and some had automatic locking hubs..it would be a lot easier to give advice if we knew the year,and if its manual 4 spd,automatic,1/2 ton,etc..:crazy:
     
  11. K5Jimmy

    K5Jimmy 1/2 ton status

    Joined:
    Sep 21, 2000
    Posts:
    1,141
    Likes Received:
    0
    Location:
    Lake Dardanelle/Logan Co, Ark
    Also...if the sound is somewhat different than a "knock" such as the TC hitting the floor...check the fluid level in the transfer case...it may be a worn chain...the 241 in my 89 did that.....replacing the chain is annoying, but not that bad.....the TC mount may not look that bad just by visual inspection and if it goes long enough you'll crack the tailhousing or worse...
     

Share This Page