88 Country Squire makes loud humming noise at highway speed

Discussion in 'General Automotive Tech' started by DynamoSquire, Dec 22, 2017.

  1. DynamoSquire

    DynamoSquire New Member

    Joined:
    Dec 22, 2017
    Messages:
    3
    Likes Received:
    4
    Trophy Points:
    3
    Wagon Garage:
    1
    My 1988 Ford Country Squire recently started making a loud hum from the rear of the car when accelerating over 65 miles an hour. The noise only happens when holding the accelerator, and will stop roughly 2 seconds after releasing it. The noise only happens when holding the pedal, so I can roll down a hill at say 75 miles an hour and only pressing the gas pedal will make the noise appear.

    I suspect its something with the transmission but am not sure.

    Engine is a fuel injected 87 5.0 with a 4 - speed ford AOD
     
  2. 63Fowagon

    63Fowagon Well-Known Member

    Joined:
    Sep 22, 2014
    Messages:
    213
    Likes Received:
    43
    Trophy Points:
    45
    Wagon Garage:
    1
    Location:
    Toronto, Ohio
    Check your rear differential oil . Sounds like a rear end noise . Rear axle noise when coasting not under load of accelerator .
     
  3. Silvertwinkiehobo

    Silvertwinkiehobo "Everything that breaks starts with 'F.'"

    Joined:
    Apr 21, 2014
    Messages:
    14,928
    Likes Received:
    2,950
    Trophy Points:
    710
    Location:
    New Braunfels, TX
    Yes, check your diff level, and check for evidence of fluid leakage.
     
  4. Grizz

    Grizz Are we there yet???

    Joined:
    Mar 4, 2016
    Messages:
    2,410
    Likes Received:
    982
    Trophy Points:
    398
    Wagon Garage:
    1
    Location:
    Nashville, TN
    U-joints? Jiggle the drive shaft?
     
  5. Silvertwinkiehobo

    Silvertwinkiehobo "Everything that breaks starts with 'F.'"

    Joined:
    Apr 21, 2014
    Messages:
    14,928
    Likes Received:
    2,950
    Trophy Points:
    710
    Location:
    New Braunfels, TX
    U-joints make noise all the time. The fluid level and fluid condition both need to be looked at, and whether there is slop and damage to the internals.
     
  6. DynamoSquire

    DynamoSquire New Member

    Joined:
    Dec 22, 2017
    Messages:
    3
    Likes Received:
    4
    Trophy Points:
    3
    Wagon Garage:
    1
    U joints are decent shape from what I can tell. Got a chance to go under the car today and the there's some minor leakage around rear differential cover, so I suspect it might be fluid (or rather lack there of) issue. Going to get a new gasket/change the fluid out after the holiday and see if that fixes it.
     
  7. Silvertwinkiehobo

    Silvertwinkiehobo "Everything that breaks starts with 'F.'"

    Joined:
    Apr 21, 2014
    Messages:
    14,928
    Likes Received:
    2,950
    Trophy Points:
    710
    Location:
    New Braunfels, TX
    When you do it, there's an area under the ring gear that collects metal bits if the gear teeth begin to chip. And check to see if the cover has a magnet on the inside; clean it if it does, to see if there are chips or shavings on it.
     
    Grizz likes this.
  8. Grizz

    Grizz Are we there yet???

    Joined:
    Mar 4, 2016
    Messages:
    2,410
    Likes Received:
    982
    Trophy Points:
    398
    Wagon Garage:
    1
    Location:
    Nashville, TN
    This was one of the first things I did. There wasn’t any noise, maybe some minor leaking but there was a chrome replacement cover at the shop that just so happened to fit. Get a chrome one! I think the cover and bolts can be bought fairly cheap
     
  9. KevinVarnes

    KevinVarnes Well-Known Member

    Joined:
    Apr 11, 2010
    Messages:
    3,028
    Likes Received:
    310
    Trophy Points:
    195
    Wagon Garage:
    1
    Location:
    Grand Rapids, MI
    Check to make sure there isn't a trail of fluid from the pinion back to the bottom rear of the diff. That would indicate a pinion seal. Either way it sounds like a good time to refresh the fluid. Make sure you add limited slip additive if you have a Trak-Lok rearend.
     
  10. Paladin62

    Paladin62 Well-Known Member

    Joined:
    Dec 15, 2016
    Messages:
    323
    Likes Received:
    213
    Trophy Points:
    101
    Wagon Garage:
    2
    Location:
    Texas
    I have a vibration coming from the drivetrain. No u joint noises, but a eremitic vibration that get more intense over 60 mph.
    I'm thinking rear end. My unit is non posi and I was going to get an Eton unit to replace it but now I think I'll need the ring and pinion gear too.
     
  11. Silvertwinkiehobo

    Silvertwinkiehobo "Everything that breaks starts with 'F.'"

    Joined:
    Apr 21, 2014
    Messages:
    14,928
    Likes Received:
    2,950
    Trophy Points:
    710
    Location:
    New Braunfels, TX
    Before you hop on that bandwagon, get the axle off the ground, give the whole unit a going over. You can also start the car, run it up to 60 mph in high gear, see if you see anything, like a driveshaft, slip yoke or pinion problem.
     
  12. OldFox

    OldFox Curmudgeon

    Joined:
    Feb 20, 2013
    Messages:
    1,318
    Likes Received:
    338
    Trophy Points:
    195
    Location:
    West Tn
    Also check the driveshaft for any evidence that you've thrown one of the balance weights.
     
  13. annap01gt

    annap01gt Blue Safari

    Joined:
    Feb 6, 2013
    Messages:
    1,933
    Likes Received:
    693
    Trophy Points:
    271
    Location:
    Sw Florida and still above water
    Dynamosauire: As others have already discussed it seems most likely mechanical but suggest, if you can do this safely, to rotate wheels from back to front to totally eliminate any balance/ tread separation possibilities.
     
  14. Paladin62

    Paladin62 Well-Known Member

    Joined:
    Dec 15, 2016
    Messages:
    323
    Likes Received:
    213
    Trophy Points:
    101
    Wagon Garage:
    2
    Location:
    Texas
    I was on the highway the other day...vibration was a bit worse, then all of a sudden...the wagon started to shake all over...
    I coasted to the shoulder and inspected underneath...everything looked ok...I was able to creep off the highway then called AAA to take me home.
    Turns out one of the end caps of the U joint at the pinion came off!!! So proud of "Sarge" as they say in the Army, "no man left behind". He didn't leave me stranded on the highway.
    I replaced the U joint, but the pinion seal is leaking now (go figure!) . That's gonna push the rear end project to the front of the line. Gonna purchase and have installed a posi-tract unit. Not sure yet which one to get...I don't need a "high HP unit"...just want to be able to pull the boat up the ramp safely.
    Any recommendations?
     
  15. Paladin62

    Paladin62 Well-Known Member

    Joined:
    Dec 15, 2016
    Messages:
    323
    Likes Received:
    213
    Trophy Points:
    101
    Wagon Garage:
    2
    Location:
    Texas
    OK. I replaced the U=joint...OMG!!! it drives like a new car!!
    I am looking for a 700R4 to replace the 350 Turbo. I also found a shop near Houston that will install the posi unit for $1,150. So, that's the plan...
     

Share This Page