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Technical Wheel hop

Discussion in 'Traditional Hot Rods' started by LKPar1270, Aug 25, 2019.

  1. LKPar1270
    Joined: Oct 31, 2008
    Posts: 77

    LKPar1270
    Member

    I need help! I've dealt with the left front tire dribbling at speeds between 55 and 59 ever since I got my Jaloy on the road, about 5 years ago. I've tried every thing I can think of to cure this. I've had my tires balanced, rebalance, and checked again, at different tire centers. I've swapped the tires around several times, swapped brake drums side to side, crossed my fingers, threw salt over my shoulder, and banged my head against the wall, all to no avail. I've checked brake drum runout, .017 on left, .018 on right, which seems excessive to me but the right side runs smooth, left side bounces. I checked wobble, .008 right and left measured just outside the bolt circle. Thought maybe the shock on the left was bad so took off both front shocks, no change in driveability or change the dribbling of the left tire. I had set the caster when building this at 5 degrees, changed it to 6 then 7 degrees with no noticable effect. One thing I can't, or at least don't know how to, change is the camber, I have 0 degrees on the left and -2 degrees on the right. I think this may account for the over steer I get, mostly on right hand corners, but dont know if this can contribute to the bounce. I'm running the original '29 Model A axle and springs, minus one leaf, and replaced the original cross member with a 1 1/2 inch drop one. Anyone have an idea of what I am missing here?
     
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  2. squirrel
    Joined: Sep 23, 2004
    Posts: 46,707

    squirrel
    Member

    did you try installing good shock absorbers?

    Camber is adjusted by bending the axle.
     
  3. 6sally6
    Joined: Feb 16, 2014
    Posts: 1,222

    6sally6
    Member

    Stiffer shock(s)? I guess you checked the car for "square" (measure from left front to right rear and compare to the other side) Front axle 'square'/90* to frame rails?
    Hope you git-it.
    6sally6
     
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  4. LKPar1270
    Joined: Oct 31, 2008
    Posts: 77

    LKPar1270
    Member

    I have Houdaille lever shocks on front, they work well. I took them off and adjusted them using a torque wrench so they have very close to the same action on compression and rebound. I dont completely roll them out as the cause, but taking them off did not change anything.
    I spent a lot of time when I started building this on getting the frame square and level. I am confident it is square.
     
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  5. VANDENPLAS
    Joined: Dec 14, 2009
    Posts: 2,570

    VANDENPLAS
    Member

    Sounds like a shock or spring issue
     
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  6. dirt t
    Joined: Mar 20, 2007
    Posts: 4,662

    dirt t
    ALLIANCE MEMBER
    from Kingman,AZ
    1. HAMB Old Farts' Club

    I'm not understanding dribbeling?
     
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  7. LKPar1270
    Joined: Oct 31, 2008
    Posts: 77

    LKPar1270
    Member

    Left tire bouncing
     
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  8. SR100
    Joined: Nov 26, 2013
    Posts: 805

    SR100
    Member

    Did you swap the shocks side-to-side to see if the issue moves too? (This is essentially the low-buck version of Squirrel's advice...)
     
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  9. Houdaille shocks are side specific. Maybe you have wrong shock on left side.
     
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  10. Is the tire perfectly round?May need to be shaved?
    Course that should show up at speeds before 55.
     
  11. F-ONE
    Joined: Mar 27, 2008
    Posts: 2,273

    F-ONE
    Member
    from Alabama

    Not to sound sarcastic but are you sure it's bouncing on just the left side?
    You may only see on the left because the left is .....the side you see as a driver.....

    Being a transverse spring it may have some attributes with a semi elliptical.
    Here is the trouble shoot for a F1 ... of course it's a semi elliptical suspension vs transverse but it may apply.

    Wheel Tramp...
    loose connecting rod ends
    loose drag link ends
    loose spring clips ( U bolts)
    broken spring tie bolts
    broken spring
    loose steering gear mountings
    wheel balance
    steering gear bind
    radial run-out
    lateral run-out
    spring sag
    loose or worn shock absorber
     
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  12. buffaloracer
    Joined: Aug 22, 2004
    Posts: 800

    buffaloracer
    Member
    from kansas

    I think it would be interesting to see what things look like when using a spin balancer on that wheel. I'm talking about the kind that spins the tire when it is still attached to the axle.
     
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  13. Stogy
    Joined: Feb 10, 2007
    Posts: 16,632

    Stogy
    ALLIANCE MEMBER

    Did you try balance beads...I'm running them on a What I suspect is a Coker Piecrust With Lead weights and it has bandaged most of the nastiness...

    How old are the tires...why...because at some point the belting in the bias was changed out to a belt that didn't get flat spots.
     
    Last edited: Nov 7, 2019
  14. Stogy
    Joined: Feb 10, 2007
    Posts: 16,632

    Stogy
    ALLIANCE MEMBER

    Those may be as rare as Tire Shavers these days.
     
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  15. Mr48chev
    Joined: Dec 28, 2007
    Posts: 27,341

    Mr48chev
    ALLIANCE MEMBER

    I've got two of them that I picked up over the past few years, the second because a strobe balancer came with it. LKpar1270 Have you had the tires spun while they were on the car?
    this one has adapters I never knew existed.
    [​IMG]

    Thing is when you have issues like that and you take the tires off and put them on the finest off the car spin balancer made with an operator that gets called on to teach others because is so good it still doesn't tell you if the brake drum / rotor is out of balance or even if the hub cap is out of balance if you have heavier hubcaps.
    It's still a process if elimination though. If you spin the tires on the car and it is glass smooth that eliminates the wheel/tire/ hub and drum from the equation and then you look at those things that F-1 listed and that looks like it is from experience and not a bit of guessing.
     
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  16. Stogy
    Joined: Feb 10, 2007
    Posts: 16,632

    Stogy
    ALLIANCE MEMBER

    You addressed the OP but No I have not and would take advantage of shaving and this form of vintage balance as I do believe that balancer you show would address the full dynamics of what you mention...The other caveat is you have to make all those goodies you have function but that is quite a neat Swapmeet Snag indeed.​
     
  17. LKPar1270
    Joined: Oct 31, 2008
    Posts: 77

    LKPar1270
    Member

    I guess it's time for me to eat a little crow. My wife seldom rides with me, and I cannot see that right tire. Talked her into riding along last night and she says the right side is doing the same as the left. The shocks are on the correct side, when I got the truck it had 4 of them, 3 worked well so I pumped the crud and water out of them, flushed them with fresh hydraulic fluid, put them on and filled them. Had tractor fluid so that's what I used. Today I'm gonna flush them and fill with Jack fluid, see if that does the trick, if not I'll go to a heavy fluid.
    Thanks for all the input, I'll let you know how it works out in a couple of days.
     
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  18. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 2,600

    2OLD2FAST
    Member
    from illinois

    I fought this on my tbucket a few years ago.....twice........first time it was an out of round REAR tire , yes , rear .......few years later it was a front shock that lost it's gas charge ....
     
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  19. Crow ain't that bad if you cook it with garlic and coconut.
     
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  20. jcforgives
    Joined: Sep 1, 2010
    Posts: 73

    jcforgives
    Member

    I had same problems I installed new rotors that I bought Wagner brand and that fix it


    Sent from my iPad using The H.A.M.B. mobile app
     
  21. Mr48chev
    Joined: Dec 28, 2007
    Posts: 27,341

    Mr48chev
    ALLIANCE MEMBER

    Actually I am damned good at making that unit function. I first learned when I was 15 in high school shop and used them at work in different shops for years and when I taught Auto Mechanics with much of the same equipment I had used in class years before even though the class was in a new larger shop at the newer school.
    Still it will tell you a lot just by spinning the wheel with the motor to see if something is or isn't out of balance. Eliminate the easy ones and then work on the hard ones.

    LKpar1270 If you slide your hand around the tread of the tire do you feel any areas that feel cupped out a bit that may be somewhat evenly spaced around the tire? That is often the tattle tale indicator of bad shocks or shocks that aren't working right. You see it a lot on tires on 4x4 trucks but I have seen it on car tires a number of times. You will probably have to feel it more than see it though.
     
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  22. Stogy
    Joined: Feb 10, 2007
    Posts: 16,632

    Stogy
    ALLIANCE MEMBER

    Perfect...Win, Win, wish you were closer I'd pay for that service in a heartbeat...Literally days ago I had a mechanic spin balance and re-weight the wheels accordingly and swap them side to side. I had Road Force balance done several years ago and added Balance Beads last year. So the Balance and Swap/Rotation this time with beads intact has made a noticeable difference but I have not been above 55mph yet.

    Technically I'm only supposed to run beads but at this point in time with 3 Ounces of beads per tire I believe the weights help. Note that one of my front tires has a slight out of round condition masked by the balance...and like you say with the Buick Drums, Caps and Trim rings how does it all work together...That why that machine would make a lot of sense.
     
  23. X-cpe
    Joined: Mar 9, 2018
    Posts: 983

    X-cpe

    No change in tramp with the shocks removed means the shocks can't control whatever is causing the tramp, not proof that they are good. More likely that they are totally ineffective. Have you tried checking the radial runout of the tire mounted on the hub and drum? Was the bolt pattern re-drilled, perhaps inaccurately? Have you tried lowering the air pressure in the front tires?
    One possibility from F-ONE's list is front spring U bolts not tight. You removed one leaf and installed an aftermarket lowering crossmember. An error stack may mean that, while the U bolts are tight, they may not be clamping the spring properly. If that is the case it may be exacerbating your oversteer problem. From your avatar, I suspect the over steer's main cause is that rear suspension is a little stiff for the weight it is carrying. The rule of thumb for a cross camber over .5* says that a car should pull to the side most positive, so if your car has a pull it should be to the left.
     
  24. Vic Walter
    Joined: Jan 21, 2018
    Posts: 91

    Vic Walter
    Member

    Basket balls bounce well as a factor of air pressure, less pressure less bounce. Is running a softer tire pressure a valid test ? Too low a pressure for to many miles will lead to a failure but a short test might make a difference. All tires will have some bounce, effective shocks will control most of it
     
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  25. christmas tree
    Joined: Dec 7, 2009
    Posts: 337

    christmas tree
    Member

    My roadster did it after running it several times in the quarter. Im puzzled. What happened, what changed. These numbers were as follows not a misprint. 5/8 tow in and 28 lb tire pressure no bounce straight as an arrow. Let it sit all winter and spring strip prep aired the ft tires up 45 lbs [tire gauge was bad I later found out] To the strip I went. Super tire bounce. Loaded it up and went home, then started checking reset tow in to 1/8 in DON,T let grand son read the tape when setting the tow in Lesson learned. Let the tires down to 28 lb air and at 100 you can take your hands off the steering wheel. New tire gauge. Too much tow in got by, to much tire pressure and too much tow in, VERY SHITTY combo. Check your numbers.
     
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  26. clem
    Joined: Dec 20, 2006
    Posts: 2,967

    clem
    Member

    For some tyres, could this cause a problem , putting them out of shape initially ?
     
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  27. clem
    Joined: Dec 20, 2006
    Posts: 2,967

    clem
    Member

    Does anyone know what type of tyres the OP is running ?
     
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  28. oldbanger71
    Joined: Nov 18, 2008
    Posts: 131

    oldbanger71
    Member

    Interesting.... curios what cure you have finaly.
     
  29. jcforgives
    Joined: Sep 1, 2010
    Posts: 73

    jcforgives
    Member

    I had a 34 panel truck hopping at 55 I put new Wagner brake rotors on it and that fix it
     
  30. I was thinking this same thing when I had a tire bouncing, but to tell the truth I fixed it by running higher pressure. That after new king pins, new tires, messing with toe-in adjustment did not fix it. Boy, I won't forget that!
     
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