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.
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?
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
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
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.
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?
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..
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
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?
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]
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. Sent from my SM-T580 using The H.A.M.B. mobile app
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.
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.
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?
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.
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.
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....
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
Haven't been on here in quite a while, nor worked much on the Jalopy either. I have fixed the bounce problem though. After putting the 3rd pair of Nissan brakes on and the bounce was no better, maybe even a little worse, I decided to try running with no brake drums. Walla! No more bounce. I've decided the problem must have been those big Nissan brakes were just too much rotating mass for 90 year old, light weight mono spring suspension. I put disk brakes on, still no hop, and took it to 100 mph with no hop. Didn't want disks 'cause it doesn't fit the traditional hot rod I originally went for, but it's safer to drive.
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