RT4WD 30+ MPH Gear whine

XdmonXXdmonX Band Wagon
in Engine & Drivetrain
Searched the site but didn't really find any info on my issue, I have a 1991 RT4WD that when I get above 30 MPH I get a high gear type whine, ive already flushed gear oil in both rear diff and transmission and its really hard to pinoint the whine. looking here to see if anyone's had a similar issue before I throw parts at it. Thank you for your help.

Comments

  • SiWagonSiWagon Council Member
    Try shifting out of 4wD mode to see if whine goes away.
  • XdmonXXdmonX Band Wagon
    SiWagon wrote: »
    Try shifting out of 4wD mode to see if whine goes away.

    tried both in and out of 4WD. also doesn't do it right away takes about 10 miles of driving.
  • XdmonXXdmonX Band Wagon
    Anyone have any ideas?
  • 90 RT4WD (Cody)90 RT4WD (Cody) Senior Wagonist
    Try your speedo cable, mine Was going bad, it sounded like a wine that was coming from the tranny, but the cable was just going bad on the end that connected to the top of the tranny. Try disconnecting the cable from the top of the tranny, and drive.

    It would take about 5-10 miles to start making noise as well.

    This would at least rule something out.

    Your issue sounded just like what mine was doing.
    Hope this helps!
  • XdmonXXdmonX Band Wagon
    I'll try that! Thanks!
  • ChaifeChaife Instagram grand master
    (Cody) is right. Try lubing your speedo cable at least. At the back of the cluster where the cable attaches to the gauge.
    Just blast some WD-40 down in the cable's housing. also lube the cluster's little "wheel assembly".
    This happen to my '87 RT wagon last year.. I chased the problem for about a week.

    does it squeak or howl no matter which forward gear you are in?
  • 1988rt1988rt Senior Wagonist
    Chaife wrote: »
    (Cody) is right. Try lubing your speedo cable at least. At the back of the cluster where the cable attaches to the gauge.
    Just blast some WD-40 down in the cable's housing. also lube the cluster's little "wheel assembly".
    This happen to my '87 RT wagon last year.. I chased the problem for about a week.

    does it squeak or howl no matter which forward gear you are in?
    I did lithium grease on mine and it went completely quiet, it was not whining it sounded like i had a mouse wheel in my cluster the faster i went the faster the mouse ran lol
  • luis808luis808 Wagonist
    I had a similar issue. Mine was bad wheel bearings though. When I made a hard turn it would go away. It only happened over 35 too. Just something to check out if the speedo cable is not the issue.
  • XdmonXXdmonX Band Wagon
    Yeah it does it in each gear, If I go above 30. It's a squeal/whine like a transmission would make when our of gear oil. I'll try that as well.
  • XdmonXXdmonX Band Wagon
    luis808 wrote: »
    I had a similar issue. Mine was bad wheel bearings though. When I made a hard turn it would go away. It only happened over 35 too. Just something to check out if the speedo cable is not the issue.
    It could be but the noise will not start until I drive about 10 miles then I'll start hearing it. And once I start slowing and get hit 30mph, It completely stops.
  • marcuskarsmarcuskars Band Wagon
    My 91 RT is doing this exact same thing. I just havent had time to tear into it yet. Mine doesnt start till I drive a certain amount of miles as well... Did you try the speedo cable? Was that the issue?
  • XdmonXXdmonX Band Wagon
    marcuskars wrote: »
    My 91 RT is doing this exact same thing. I just havent had time to tear into it yet. Mine doesnt start till I drive a certain amount of miles as well... Did you try the speedo cable? Was that the issue?
    Doesn't seem to be the speedo cable. Took it out today and drive and it's still there. Still looking though!
  • XdmonXXdmonX Band Wagon
    Speedo and wheel bearing ruled out, also doesnt seem to be coming from the transmission, possibly rear diff?
  • XdmonXXdmonX Band Wagon
    Could something in the VC cause a whine like this?
  • 90 RT4WD (Cody)90 RT4WD (Cody) Senior Wagonist
    Maybe change the oil in the rear diff? just to rule that out too.
  • marcuskarsmarcuskars Band Wagon
    Did you ever figure out what it was?
  • XdmonXXdmonX Band Wagon
    90 RT4WD (Cody) wrote: »
    Maybe change the oil in the rear diff? just to rule that out too.
    Did that as well and no difference.
  • XdmonXXdmonX Band Wagon
    I'm thinking VC but I recently hydro locked my wagon so I'm waiting for my new motor to come in and then I will get back to trying to pin point the noise.
  • SiWagonSiWagon Council Member
    Does that mean your engine is out?You should open the
    left side transfer cover(next to where the rear center axle attaches to the tranny.A cover w/ 5 bolts) to check the brg & Thrust shim adjustment.
    Also open & check the Driven gear assembly (A heavy piece that concise center axle flange ,6 bolt cvr,brg,& transfer gear)where the rear center axle attaches to the tranny.) to check the brg & backlash.
    This could be a early sign of the brg going bad.My brg exploded.I couldn't even find the brg except for the outer brg. race.The transfer area seems to be a weak point for the 4WD Wgn.I've seen a many 4WD trannies going bad this way.
  • marcuskarsmarcuskars Band Wagon
    So I found out that my whine was coming from my carrier bearings on the drive line. There is 2 of them on both sides of the viscous coupler. They being a pain to source!
  • 90 RT4WD (Cody)90 RT4WD (Cody) Senior Wagonist
    Try calling like SKF or Timken bearings and give them the number on the bearing.

    This may help ?
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