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Technical Wheel hop

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

  1. DAHEMIKOTA
    Joined: Aug 12, 2006
    Posts: 117

    DAHEMIKOTA
    ALLIANCE MEMBER
    from Tenn

    That is the same thing I did to my 69 Dodge truck that I raced at the drag strip. It had wheel hop and the only way to stop it was to jamb the brakes hard. Tried a bunch of alignment tricks and nothing worked. I took the bias ply tires off the front and installed a set of radials on the front. Never had the problem again.
     
  2. The Shift Wizard
    Joined: Jan 10, 2017
    Posts: 1,661

    The Shift Wizard
    ALLIANCE MEMBER

    So much has been checked out. The only other thing I can think of is if there is a twist in the 4 corners of the suspension. IE, what is the weight load to pavement of each tire?
     
  3. LKPar1270
    Joined: Oct 31, 2008
    Posts: 77

    LKPar1270
    Member

    These are the second set of tires I've had on it, first were bias ply, then 3 years ago I went to radials. Bounced like crazy with the bias plus, but still bouncing. I'm at my wits end. Thought balancing that brake drum would do the trick, but it only helped some. Im gonna build a tube shock setup with bigger shocks, something for a much heavier car. If that doesn't work I'm going to put disks on it. I would rather keep the drums just because they are what would have been used in the early 60s or late 50s, which is the period I wanted this to resemble. Anyone else using disks on their Traditional rods?

    Sent from my SM-T580 using The H.A.M.B. mobile app
     
    loudbang likes this.
  4. LKPar1270
    Joined: Oct 31, 2008
    Posts: 77

    LKPar1270
    Member

    Btw Shift Wizord, I've never checked the weight per wheel, but lifting from the center of either axel lifts both tires on that axel at the same time. Adding a passenger makes no noticable difference either

    Sent from my SM-T580 using The H.A.M.B. mobile app
     
  5. Blues4U
    Joined: Oct 1, 2015
    Posts: 4,281

    Blues4U
    Member
    from So Cal

    Go to the locqal motorcycle shop and get some front fork oil, i tis designed for suspension use. Hydraulic jack oil is probably the worst I could think of to use. Fork oil will have the necessary anti-foam additives to break up any foam and release it so it doesn't accumulate and make the shocks worthless. Plus it has anti-wear additives, and it will have lubricity additives to reduce stiction, and conditioners for the seals. And it comes in different viscosities, so try one, if it doesn't seem to have enough damping effect try a heavier viscosity. Jack oil? WTF???? Jacks move up , and then after a while they move down. Basic non-additized mineral oil would work for that.
     
    Stogy and loudbang like this.
  6. Dan Timberlake
    Joined: Apr 28, 2010
    Posts: 1,251

    Dan Timberlake
    Member

    Have you checked the static balance of the wheel tire assemblies when mounted on the car, with brake shoes temporily backed off, similar to what you did to find the out of balance brake drum?
     
  7. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 1,868

    2OLD2FAST
    Member
    from illinois

    May sound silly but your shocks may be doing there job but your frame isn't , focus on the top of the radiator while bouncing. look for side to side movement..
     
  8. LKPar1270
    Joined: Oct 31, 2008
    Posts: 77

    LKPar1270
    Member

    2old2fast, I haven't wanted to admit that that may be the problem, but I've thought about that a lot, you may be exactly right. I boxed the frame, welded in new front cross member and added a cross member to support the engine instead of just hanging from the frame. I also welded everything that had originally been riveted. Still, it's a pretty flat frame, and I'm sure it can easily flex.

    Sent from my SM-T580 using The H.A.M.B. mobile app
     
  9. lippy
    Joined: Sep 27, 2006
    Posts: 4,232

    lippy
    Member
    from Ks

    So maybe a chassis pre-load problem also? Lippy
     
  10. Do you have Nissan brake drums on the F1 hubs? If the redrilling was off, or if the drum didn't fit the hub you'd be getting some brake peddle feedback. Are you sure the wheels mate properly to the Nissan Drums? Did you consider later F150 Drums (no machining required)? Any front end pics?
     
  11. This made me laugh....damn near every part in a beam axle can cause Wheel Tramp.


    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[/QUOTE]
     
  12. LKPar1270
    Joined: Oct 31, 2008
    Posts: 77

    LKPar1270
    Member

    Roadside, everything on your list has been replaced or checked in the last couple of weeks. Axel was changed out with a verified good one with new 40 Ford style spindles. Runout was checked on the brake drums and was within specs. New kingpins were installed with the axel and new spindles. Tie rod and steering arm joints are all tight. Here's a picture of the front end, after axel and spindle upgrade but before I put the shocks back on. 20191105_074609.jpeg

    Sent from my SM-T580 using The H.A.M.B. mobile app
     
  13. Don't know if it's been mentioned but when mine wanted to wobble/bounce with radials, I removed all the front wheel balancing weights and poured tire balancing beads into the tires. Fixed it.
     
    clem and Stogy like this.
  14. -Brent-
    Joined: Nov 20, 2006
    Posts: 5,012

    -Brent-
    Member

    A pal of mine went through the list you've gone through. For a while, he just tolerated the vibration until it affected his radiator. He pulled the radiator to repair it and there he found that one of the U-bolts, fastening the front spring, was cracked/broken.

    He assumed it was an effect and not a cause. Fixed the radiator and continued on. First drive, the problem was gone.
     
    loudbang, clem and Stogy like this.
  15. Stephen Barrett
    Joined: Sep 24, 2019
    Posts: 726

    Stephen Barrett
    ALLIANCE MEMBER

    Actually had someone suggest balance beads to me last week. I haven't tried them yet but I plan on it. How much of a difference did it make for you?
     
    Stogy likes this.
  16. Stephen Barrett
    Joined: Sep 24, 2019
    Posts: 726

    Stephen Barrett
    ALLIANCE MEMBER

    Glad to here that I was going to do the same.
     
  17. Atwater Mike
    Joined: May 31, 2002
    Posts: 9,855

    Atwater Mike
    ALLIANCE MEMBER

    Glad that steering dampener got mentioned... :rolleyes: Bring a band aid to a shooting.
     
  18. Stogy
    Joined: Feb 10, 2007
    Posts: 14,397

    Stogy
    ALLIANCE MEMBER

    From 0-65 mph the bounce has been pacified, above 65 it gets shaky and I don't take it there if I can help it. I believe one of the front tires has quality issues and I have not replaced it...I don't have warranty on these tires and will drive them out as I don't spend much time above the smooth zone as the Highway speeds here don't accommodate higher...and I don't visit the superhighways often...65mph is good for the slow lane anyways.

    I have 3 ounces in each tire...I have not taken the weights off.
     
  19. Stephen Barrett
    Joined: Sep 24, 2019
    Posts: 726

    Stephen Barrett
    ALLIANCE MEMBER

    Cool! Definitely going to get some. If I could go 60-65 on the highway without rattling the fillings out of my teeth that would be great. I don't go on the highway much and I can go 50mph pretty comfortably but 65 on the highway would be nice.
     
    Stogy likes this.
  20. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 1,868

    2OLD2FAST
    Member
    from illinois

    Walking with a cane is better than not being able to walk at all.....
     
  21. Hudson31
    Joined: Feb 22, 2013
    Posts: 27

    Hudson31
    Member

    Sent from my iPhone using H.A.M.B.
     
  22. LKPar1270
    Joined: Oct 31, 2008
    Posts: 77

    LKPar1270
    Member

    20191108_150814.jpg




    Sent from my SM-T580 using The H.A.M.B. mobile app
     
    Last edited: Nov 10, 2019
  23. Stephen Barrett
    Joined: Sep 24, 2019
    Posts: 726

    Stephen Barrett
    ALLIANCE MEMBER

    I couldn't see the attachment but good advice. Thanks.
     
  24. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 1,868

    2OLD2FAST
    Member
    from illinois

    While the new cross member is a needed improvement ,if you really want to increase lateral / torsional rigidity, look at K members or X members....
     
    Last edited: Nov 10, 2019
  25. can you put a couple pictures of the frame, front suspension, radius rods, close-ups, side, etc.

    I see you have really deep drop radius rod mounts. is there any possibility that they are flexing? i am not a fan of the really deep drop mounts
     

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