• Welcome to SVTPerformance!
ATTENTION!
You may experience intermittent issues while accessing the site over the next 60-90 minutes, as we perform maintenance and upgrades.

Vibrations at higher speeds. Any ideas?

Discussion in 'SVT Shelby GT500' started by builttodrive, May 5, 2021.

  1. builttodrive

    builttodrive Member Established Member

    Messages:
    514
    Joined:
    Oct 26, 2014
    Location:
    Sioux Falls, SD
    I get what appears to be a driveline vibration at about 100+ MPH and it get's worse and more violent the faster I go. Anything below 100 is perfectly smooth. It doesn't have anything to do with RPM and I have tried different gears including neutral and coasting and there is no change. I recently had my rear end gone through and axles inspected so I think I can rule that out. I have a Drive Shaft Shop 1 piece aluminum shaft that I have tried rotating 180 degrees and it may have made a slight difference but nothing big. I then took the driveshaft to my local driveline shop and they balanced the shaft. For wheels on the car I have American muscle 2010 GT500 style wheels with Michelin Pilot Super Sport tires and I have had the wheels checked for true and a trusted shop road force balanced them and didn't find anything of concern.

    The vibration gets worse with speed and has no effect on the steering wheel. The whole car seems to be affected and can be seen by vibrations in the dash or rear view mirror. It stays the same wether I'm accelerating or coasting anywhere above 100 or so MPH.
     
  2. me32

    me32 BEASTLY SHELBY GT500 TVS Moderator

    Messages:
    17,036
    Joined:
    Sep 6, 2005
    Location:
    CA,NorCal
    Check your suspension
     
  3. builttodrive

    builttodrive Member Established Member

    Messages:
    514
    Joined:
    Oct 26, 2014
    Location:
    Sioux Falls, SD
    What should I check? I have Griggs Racing suspension on the car that has KONI adjustable coilovers on it. It has a torque arm setup with watts link.
     
  4. me32

    me32 BEASTLY SHELBY GT500 TVS Moderator

    Messages:
    17,036
    Joined:
    Sep 6, 2005
    Location:
    CA,NorCal
    Check that everything is still tq to spec. A loose nut could cause vibrations at that speed. Check components for cracks or breaks, lube up any thing that is serviceable
     
  5. LuuisHernandez

    LuuisHernandez Active Member Established Member

    Messages:
    525
    Joined:
    Dec 15, 2015
    Location:
    California
    Loose lug nuts? Worth checking lol


    Sent from my iPhone using svtperformance.com
     
    me32 likes this.
  6. me32

    me32 BEASTLY SHELBY GT500 TVS Moderator

    Messages:
    17,036
    Joined:
    Sep 6, 2005
    Location:
    CA,NorCal
    Thinking about it. You having a griggs kit. Is the 1 pc driveshaft have the correct pinion angle? That will definitely give vibration. I know alot of griggs kits still use the factory 2pc.
     
  7. builttodrive

    builttodrive Member Established Member

    Messages:
    514
    Joined:
    Oct 26, 2014
    Location:
    Sioux Falls, SD
    I'll check into it again. I think I researched that before and I'm thinking with the style end the driveshaft has it isn't as influenced by the pinion angle as a Ujoint. I had all the rear suspension out here recently and everything looked good from what I could see there.
     
  8. HKusp

    HKusp Active Member Established Member

    Messages:
    333
    Joined:
    Apr 17, 2019
    Location:
    Perry Hall, Maryland
    I have heard that some of those Michelins will do it too. Is this the same issue that you brought up last year in March?
     
  9. buddha93

    buddha93 Well-Known Member Established Member

    Messages:
    2,564
    Joined:
    Oct 31, 2002
    Location:
    St. Louis
    Almost always tires. I know you said they're balanced, but I'd check again, make sure they didn't throw a weight or have the shop recheck.
     
  10. 13COBRA

    13COBRA Resident Ford Dealer Premium Member Established Member

    Messages:
    17,460
    Joined:
    Jun 4, 2012
    Location:
    Missouri
    Tires.
     
  11. OX1

    OX1 Active Member Established Member

    Messages:
    153
    Joined:
    Sep 23, 2015
    Location:
    New Jersey
    Agree. Tires not perfectly round, can still be balanced out many times, especially on a road force.
    What were the road force numbers?
     
    builttodrive likes this.
  12. cidsamuth

    cidsamuth Liberty Biberty Established Member

    Messages:
    839
    Joined:
    Aug 16, 2010
    Location:
    Virginia
    My first instinct was to yell, "Pinion angle!"

    Especially if the car has been lowered, but the one-piece driveshaft might do it too. Depending on power levels and suspension firmness (poly vs stock rubber), you will want somewhere between -1 degree and -3 degrees.
     
    me32 and builttodrive like this.
  13. Mojo88

    Mojo88 "Hammer" Time Established Member

    Messages:
    1,190
    Joined:
    Jan 30, 2017
    Location:
    RI
    I'm saying pinion angle, or tires.

    Can you easily swap a 2-piece driveshaft back in? Just to try it out?
     
    me32 and builttodrive like this.
  14. Catmonkey

    Catmonkey I Void Warranties! Premium Member Established Member

    Messages:
    3,784
    Joined:
    May 20, 2011
    Location:
    Louisiana
    I'd say CV joint, but your driveshaft shop should have detected that.
     
    me32 and builttodrive like this.
  15. gimmie11s

    gimmie11s Don’t be an idiot Established Member

    Messages:
    13,680
    Joined:
    Jun 1, 2004
    Location:
    so cal
    Front wheel bearings. Both went out in my 2007 GT500 and the car shook at speed and sounded like hell.
     
    me32 and builttodrive like this.
  16. builttodrive

    builttodrive Member Established Member

    Messages:
    514
    Joined:
    Oct 26, 2014
    Location:
    Sioux Falls, SD
    Yes same issue. I made some changes and checked some things as mentioned above but the vibration is still there. I heard of the Michelin "death Wobble" or whatever people called it but tires seem to balance decent and It's weird that I have to be going that fast before there is any issue but I'm not sure.
     
  17. builttodrive

    builttodrive Member Established Member

    Messages:
    514
    Joined:
    Oct 26, 2014
    Location:
    Sioux Falls, SD
    I know I went down the pinion angle road before and I can't remember exactly what I found out but I think the DSS driveshaft has more range than a Ujoint ended shaft. My suspension is a 3 link setup with a torque arm. The joints on the lowers are heim joints.
     
  18. builttodrive

    builttodrive Member Established Member

    Messages:
    514
    Joined:
    Oct 26, 2014
    Location:
    Sioux Falls, SD
    Unfortunately with the torque arm suspension it's a real pain swapping out driveshafts. Most of the rear suspension and exhaust has to be removed to get it out.
     
  19. me32

    me32 BEASTLY SHELBY GT500 TVS Moderator

    Messages:
    17,036
    Joined:
    Sep 6, 2005
    Location:
    CA,NorCal
    Thats funny. I had the same issue. Both sides were shot. I assumed it was when i was road coursing at thunderhill.
     
  20. Catmonkey

    Catmonkey I Void Warranties! Premium Member Established Member

    Messages:
    3,784
    Joined:
    May 20, 2011
    Location:
    Louisiana
    I'd put the rear axle on jack stands, remove the wheels and tires and bolt on the rotors and take it up to that speed. If it vibrates, you can rule out most of the possibilities. If it passes, add the rear tires to the mix (elevated off the pavement).
     

Share This Page