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  1. #1

    Default Steering wheel vibrations at highway speeds

    I took my '84 Thunderbird to get an alignment and all four wheels balanced last Monday afternoon but I'm still getting vibrations through the steering wheel at around 50mph. This is what I've done so far to try and remedy this issue:

    1. Installed a new vibration dampener (harmonic balancer).
    2. Had new U-joints installed on driveshaft and had it balanced.
    3. Installed new front struts.
    4. Had car aligned and all four wheels rebalanced.

    I've also jacked up the front the car to check for play in my tie rod ends and wheel bearings but there doesn't seem to be any issues with either of those items. The work I've done so far has greatly reduced the severity of the vibrations but they are still present and I feel I should be able to get this car to run smoothly at highway speeds. Are there any other items that could contribute to this issue that I need to check?

    Thanks!
    Dan

  2. #2
    Moderator wraithracing's Avatar
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    I would recommend rotating the tires and see what difference if any that makes. I have a "hop" that occurs around 50 MPH on my 2004 F250 PSD. Unfortunately due to the 35" tires that's just the nature of the beast. I have had the tires balanced and other than at 50 MPH they are nice and smooth, but something about that speed causes the slight hop to occur. Once I get past 50 or below 50 the hop goes away, just something I have learned to live with. My guess would be you have a tire or tires that still have some type of imbalance at that speed. Rotating the tires might move that to the rear where it might be less noticeable or more tolerant. Good Luck!
    ​Trey

    "I Don't build it hoping for your approval! I built it because it meets mine!"

    "I've spent most of my money on Mustangs, racing, and women... the rest I just wasted."

    Mustangs Past: Too many to remember!
    Current Mustangs:
    1969 Mach 1
    1979 Pace Car now 5.0/5 speed
    1982 GT Stalled RestoModification
    1984 SVO Still Waiting Restoration
    1986 GT Under going Wide Body Conversion Currently

    Current Capris:
    1981 Capri Roller
    1981 Capri Black Magic Roller Basket Case
    1982 Capri RS 5.0/4spd T-top Full Restoration Stalled in TX
    1984 Capri RS T-top Roller
    1983-84 Gloy Racing Trans Am/IMSA Body Parts

  3. #3
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    Rotate your tires one at a time to help pin point the problem. Usually its the tire or wheel on the front that shakes the steering wheel. Rotors would cause it to shake when the brakes are applied.

    Are you sure the tire tech really checked them out or just serviced them?

    My guess is a bad tire. Inspect them closely for out of round.
    Fox Body/3rd Gen MCA Gold Card Judge
    84 SVO 24K miles, 85 Mclaren Capri Vert. 84 GT Turbo Vert.
    88 Mclaren Mustang Vert 20K miles, 89 Mustang LX Sport Vert,
    03 Mach 1 7900 miles, 74 Mustang II, 69 Mustang, 67 Mustang, 14 Mustang CS/GT,
    15 F150 FTX Tuscany, 16 F250 Crewcab, 67 Tbird 47K miles

  4. #4

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    Agree with KevinK.

    Just went through this on my thunderbird. Radial run out all 4 tires. Made for a really rough ride.

    Get the car up in the air and spin the wheel and pay close attention to the tread. Mine was hopping.
    '84.5 GT vert / roller 5 liter 4v / t5
    '86 LX coupe / 331 / t5
    '86 F-150 - 5 liter / efi / aod
    '56 F-100 - 272 y-block / 3 on the tree

  5. #5

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    Block the front tires and put the rear axle up on jack stands. Drive the car at freeway speeds like this. Then rotate all four tires and repeat. This is the fastest way to eliminate a wheel/tire balancing problem and you can visually check for tire runout.
    Jack Hidley
    Maximum Motorsports Tech Support

  6. #6
    FEP Senior Member OX1's Avatar
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    Quote Originally Posted by KevinK View Post
    Rotate your tires one at a time to help pin point the problem. Usually its the tire or wheel on the front that shakes the steering wheel. Rotors would cause it to shake when the brakes are applied.

    Are you sure the tire tech really checked them out or just serviced them?

    My guess is a bad tire. Inspect them closely for out of round.

    A lot of brand new tires are out of round these days. many just slightly, but enough to make
    an annoying vibration, even if they balance out fine.

    Here is the brand new tire that came on my brand new 17 Fusion Sport.
    Jumps around quite a bit, but zero'd out balance-wise pretty easy. .

    http://luxjo.supermotors.net/FUSION%...114_211142.mp4

    Compare that to the almost perfect PS4S Michelin's I put on it and it 100% cleared up the vibration
    even the dealer could not fix with road force balancing.

    http://luxjo.supermotors.net/FUSION%...114_211519.mp4

    Here is a 305 NT01 road course tire. Not cheap, you would think they would be made pretty good. Sent that guy back.
    I made up a wood block I can hold on top of my balancer, to see variances better, I've had so many questionable tires
    in the past 10 years or so (I own 11 of my own vehicles and do most of the friends and families tires).


    http://luxjo.supermotors.net/MUSTANG...512_120218.mp4

    Here's a really bad one.
    Bought this 14K, 26' alum car trailer couple years back.



    Beautiful trailer, but Cinese rims/tires.
    Had to get 8 of them from the dealer, to get 4 good one's.

    http://luxjo.supermotors.net/26%20FO...902_132716.mp4

    I'm not sure what the rest of you do without your own machine's to diagnose this stuff. But I would not be surprised if
    you had a bad tire, even if they are brand new.
    86 Capri, 5.0, 5Spd, A9L QH/BE, 47 lb Inj PMAS 3" MAF, Single T44 Turbo, Front Mount IC, TW170,
    Stock Cam, Explr Intake/TB, 1.7 Rockers, CF dual friction clutch, 3" DP, 2.5" full Exh, 3.27, 11.932 @ 115.78
    84 LTD, 331-10:1, TW170/Exprl Intake, 47 lbs inj/80 mm LMAF, Full Duals, Quarterhorse, Vortech 7PSI, Lentech AOD, 5 lug Mk VII brakes/rear, Eibach Sway bars, Cobra HB (dads ride, but I fix it )

  7. #7

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    With the car on jack stands I checked for runout on all four tires and none of them appeared perfectly round. When I spun the tires all of them had had areas that would rub against the end of a stationary metal rod and then spin freely. I'm not sure what amount of runout is acceptable but to the naked eye it seems mine is beyond acceptable. I went ahead and rotated the wheels to see what would happen. When I pulled the wheels off the car I could tell the shop rebalanced them as the weights were new and were attached in slightly different locations. After I got the car back on the ground I took it for a drive and the vibration is actually worse now than it was before.

  8. #8
    FEP Senior Member OX1's Avatar
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    Quote Originally Posted by Bird of Prey View Post
    With the car on jack stands I checked for runout on all four tires and none of them appeared perfectly round. When I spun the tires all of them had had areas that would rub against the end of a stationary metal rod and then spin freely. I'm not sure what amount of runout is acceptable but to the naked eye it seems mine is beyond acceptable. I went ahead and rotated the wheels to see what would happen. When I pulled the wheels off the car I could tell the shop rebalanced them as the weights were new and were attached in slightly different locations. After I got the car back on the ground I took it for a drive and the vibration is actually worse now than it was before.
    I never really looked before, for a spec, but Bridgestone says 1/8th here.

    https://www.innovativebalancing.com/Balance&RunOut.pdf

    That would never be acceptable to me and if that is what they are uses for go-nogo these days,
    no wonder why it seems so many new tires have vibes.

    One other thing I forgot o mention is tires flat spot. High perf, low profile tires seem
    worse overall to me, but even the stock AS (nothing fancy) tires on our 17 escape flat spot overnight.
    Anyway, I would drive a good distance and get tires nice and hot before checking for runout.
    86 Capri, 5.0, 5Spd, A9L QH/BE, 47 lb Inj PMAS 3" MAF, Single T44 Turbo, Front Mount IC, TW170,
    Stock Cam, Explr Intake/TB, 1.7 Rockers, CF dual friction clutch, 3" DP, 2.5" full Exh, 3.27, 11.932 @ 115.78
    84 LTD, 331-10:1, TW170/Exprl Intake, 47 lbs inj/80 mm LMAF, Full Duals, Quarterhorse, Vortech 7PSI, Lentech AOD, 5 lug Mk VII brakes/rear, Eibach Sway bars, Cobra HB (dads ride, but I fix it )

  9. #9

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    I took the car on a coffee run yesterday morning before I put it on jack stands. That trip was around 15 miles with most of that distance driven between 50 - 60mph.

  10. #10

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    You need to drive the car on jack stands with different combinations of tires installed on the rear. Feel for vibration in the car. If none of the tires on the rear axle vibrate, then you know the problem isn't any of the tires and isn't in the driveline; the problem must therefore be in the front suspension. If all of the tires vibrate the same on the rear, then the problem is in the driveline.
    Jack Hidley
    Maximum Motorsports Tech Support

  11. #11

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    I'll add my 2cents...

    - Road Force Balancing catches a lot of tire run-out problems, as opposed to static or spin balance methods.

    - Ensure the lug are torqued in a star pattern with a manual torque-wrench. [I've had a vehicle very sensitive to this].

    - Check that your wheels are hub-centric, and that your rotors are hub-centric (if not hub-integral).

    - Ensure correct lug nuts for your wheels (unusual on modern wheels, as most are conical seat).

    I don't know what tires you are using, but I don't think a 15mi drive at 50-60MPH is going to bring a Z-Speed AA-Temp Rated tire up to temperature. I've had several tires that didn't ride or perform well until a couple of really good heat cycles.
    1985 GT 5.0 CFI / AOD
    All Original

  12. #12
    FEP Senior Member OX1's Avatar
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    Quote Originally Posted by TxMike64 View Post
    I'll add my 2cents...

    - Road Force Balancing catches a lot of tire run-out problems, as opposed to static or spin balance methods.

    - Ensure the lug are torqued in a star pattern with a manual torque-wrench. [I've had a vehicle very sensitive to this].

    - Check that your wheels are hub-centric, and that your rotors are hub-centric (if not hub-integral).

    - Ensure correct lug nuts for your wheels (unusual on modern wheels, as most are conical seat).

    I don't know what tires you are using, but I don't think a 15mi drive at 50-60MPH is going to bring a Z-Speed AA-Temp Rated tire up to temperature. I've had several tires that didn't ride or perform well until a couple of really good heat cycles.
    Just curious. Anyone besides Hunter make a road force balancer? I've considered upgrading, but those road force machines are huge and still going for over 3 grand, well used.
    86 Capri, 5.0, 5Spd, A9L QH/BE, 47 lb Inj PMAS 3" MAF, Single T44 Turbo, Front Mount IC, TW170,
    Stock Cam, Explr Intake/TB, 1.7 Rockers, CF dual friction clutch, 3" DP, 2.5" full Exh, 3.27, 11.932 @ 115.78
    84 LTD, 331-10:1, TW170/Exprl Intake, 47 lbs inj/80 mm LMAF, Full Duals, Quarterhorse, Vortech 7PSI, Lentech AOD, 5 lug Mk VII brakes/rear, Eibach Sway bars, Cobra HB (dads ride, but I fix it )

  13. #13

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    The second set of tires that went on my Capri, after the gatorbacks wore down to the cords ‘cause the money was tight at the time, were Pirelli’s. The dealer that put them on wouldn’t warrant them without putting them on the grinding machine. I thought that was silly as it was cutting the life of the tire in my mind. He said the tires would last longer that way. More likely it was the proper way to make sure the tires were more perfectly round and would cut down on complaints. You might check to see if your dealer has a grinding machine or find a dealer who does.
    W

    As always, "It ain't what you don't know that gets you, it's what you think you know that just ain't so."

  14. #14
    FEP Power Member mcb82gt's Avatar
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    Quote Originally Posted by WilliamCapri View Post
    The second set of tires that went on my Capri, after the gatorbacks wore down to the cords ‘cause the money was tight at the time, were Pirelli’s. The dealer that put them on wouldn’t warrant them without putting them on the grinding machine. I thought that was silly as it was cutting the life of the tire in my mind. He said the tires would last longer that way. More likely it was the proper way to make sure the tires were more perfectly round and would cut down on complaints. You might check to see if your dealer has a grinding machine or find a dealer who does.
    I never even heard of that. lol Learned something.
    Mike

    Now stang-less.

    88 Cougar 5.0

  15. #15
    Moderator wraithracing's Avatar
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    Years ago, your independent tire shops and some of the big names used to have tire truing/shaving machines specifically for fixing tire run out issues. Really cool to see how they worked and what a difference they made on "bad" tires. I guess as tire manufacturers quality improved, there was less need for the machines and obviously as the Big Box Tire stores have taken over for the smaller independent, they just warranty out tires now rather than true them up. Used to be able to get tires shaved down for Autocrossing/Road Racing on a local level, but that is almost impossible except for larger metro areas these days it seems or an area that racing is a big deal.
    ​Trey

    "I Don't build it hoping for your approval! I built it because it meets mine!"

    "I've spent most of my money on Mustangs, racing, and women... the rest I just wasted."

    Mustangs Past: Too many to remember!
    Current Mustangs:
    1969 Mach 1
    1979 Pace Car now 5.0/5 speed
    1982 GT Stalled RestoModification
    1984 SVO Still Waiting Restoration
    1986 GT Under going Wide Body Conversion Currently

    Current Capris:
    1981 Capri Roller
    1981 Capri Black Magic Roller Basket Case
    1982 Capri RS 5.0/4spd T-top Full Restoration Stalled in TX
    1984 Capri RS T-top Roller
    1983-84 Gloy Racing Trans Am/IMSA Body Parts

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