If you can't cure it with tire pressure; maybe time to try tube shocks; I read somewhere on here that they have better control on beam axle oscillation than lever shocks. True or not? I don't know.
I have had two vehicles that experienced front wheel "hop". The first was because the tire was out of balance and the second was because my wonderful Coker tires were out of round. After having them trimmed and made round, the "hop" disappeared.
Been away from here for a few months, you guys have given me lots of good ideas here, but alas none have cured my problem. I've tried the air pressure suggestion, from 22 to 40 lbs, smooth ride with the low pressure but with no change in the bounce. I put w90 in the shocks, made a slight change in where the bounce began and ended by one mile per hour higher, so I went to tube shocks, again a change in where the bounce occurred, again another mile per hour higher. I now think it is the brake drums, they are redrilled 2000 Nissan Pathfinder brakes. I drilled them using my milling machine and a rotary table. I don't use DRO, so I suppose I could have missed the mark by a few thousandths, and these drums are pretty big. Right now I am putting new, '40 style spindles and axle on, and I will check the accuracy of my re-drilled drums before I put it back together, replacing them if I screwed up on them. By the way, I'm using F1 hubs, which have larger inner bearing races, if I go to '40 ford bearings, will the inner bearing outer race ( did I say the right?) fit my F1 hubs?
I have the same thing on my t-bucket, right front only and starts about 63 mph. I've changed air pressure, swapped tires side to side, took all four rims/tires off and switched to four different ones, added removed leaves in both front and rear springs, rechecked wheel bearing load, put those harmonic springs around the drums, just about anything you can think of. It doesn't do it running over a bumpy road at lower speeds, can't get it to replicate at lower speeds at all, only in that mid 60's speed and only on the right side, does it with 2 people in the car too, so it's not a weight balance thing. Drives me crazy !
A 14116 bearing will fit the F-1 bearing race and the '40 Ford style spindle. You should grind a radius on the inner edge of the bearing to seat properly on the spindle.
Thanks for the bearing info, gonna see if there's a pair of them in this town this morning Sent from my SM-T580 using The H.A.M.B. mobile app
Got new bearings today, ground the radius in and mounted one hub, no seal, and just light oil on the bearings and only enough preload to take up any slack. Then mounted one brake drum friction surface sticking out. I then measured runout. .004 inches, not bad. I then spun the drum and marked the point where it stopped, did this 10 times. Stopping points were pretty random. Next I set up the other durm the same way. .0065 inches runout, still not bad. Then I did the spin test. It stopped every time in an arc of only about 15 degrees! I taped a fender washer on at the light spot just outside the hub. Same test with similar results. Two more spin tests with progressively better results, but still after 3 washers it was stopping in about a 90 degree arc. 4 washers now, and I'm finally getting a random pattern. So, has anyone ballanced a brake drum? My plan right now is to drill and tap for a #10 machine screw and mount these 4 washers on the inside of the drum. Better ideas?
I'd weld the washer's on and then make a light pass on the brake lathe to make sure everything was still running true.
I prefer not to weld on the drums. Only talking about a couple of ounces here, and I'll loctite the machine screw in, cut it off almost flush and brad the nub, it'll never come out.
An on the car spin balance would be the best bet, IMO. Just trying to find someone with the equipment to do it would be a bigger P. I. T. A! I don't see any reason the way you want to do it wouldn't work, seems logical to me. But then again... I don't know that much.
i have seen a problem like you have on a truck once years ago. the bushing was worn on the steering box bottom where the steering arm is atached to the box. it caused the drag link to shake , causing the wheels to shake . just a thought.
You have to fix it all, Tire pressure, balance, shave to round, check and straighten the rims,. add a steering stabilizer to the tie rod, adjust or rebuild the steering box to remove play, change all the rod ends, tie rod replace and ream the spindle bushings/and new kingpins, replace the wheel bearings as shown with tapered roller bearings, and tube shocks. So that's your checklist. JW
I did change out the old Houdaille shocks for new tube shocks with little change. I'm betting that brake drum out of balance is the problem. I'll know as soon as I get new outer wheel bearings, probably Wednesday.
JW, missed your post. Tires are round, and balanced (have had checked 3 times since I put them on by different tire suppliers), was using steering stabilizer, steering box is tight as are tie rod ends (modern style, not the adjustable Model A ends). I have now replaced the axle and put new '40 Ford style spindles on with new bearings ( old bearings were good, but because I went to the '40 spindles had to get new inner bearings, so also am replacing the outer bearings), and of coarse new king pins and bushings though the pins on the old axle were still tight. Have had new tube shocks on it for the last 2 months. FYI, the steering box and tie rod ends were not a concern, steering is very good on this old Jalopy, I haven't had 'death wobble' since I changed from the old stock push pull steering to a '67 Chevy PU steering box with cross steering.
I had a wheel hop issue with my t-bucket...drove me crazy...had tires re-balanced several times...no change...finally one went flat and I had to buy a new tube...found one tire had the wrong size tube (too big) and the tube was folding on itself in different locations throwing off the balance....replaced the tube with new proper size and never had another issue....now also running micro beads.
Finally got the front end together. Test drive with no shocks and still have some bounce, but markedly better, but... think wandered allover the road and now I had over steer in both directions. I had set the toe to 1/8 inch, so back to the shop and increased the toe to 1/4 inch. Back out on the road and still wandering. Back to the shop and add another 1/8 inch toe. Back on the road and the wandering is pretty much gone. Back at the shop and put the knee action shocks on (i really want to use these if i can because i like the look). Bounce still isn't gone but better yet. I have lowered the tire pressure from 33 to 27, will give that a try tomorrow. Sent from my SM-T580 using The H.A.M.B. mobile app
BTW, when I put the shocks on, I noticed the bracket holding the Panhard bar was at a bit of an angle, grabbed it and it was loose. Turning the steering wheel moved the body back and forth over the axle about an inch! Gonna fire that idiot that put it back on with the new axle. With that tight the oversteer is gone. I suspect I dont need all that toe either. Sent from my SM-T580 using The H.A.M.B. mobile app
Some success here. I dropped the tire pressure from 33 to 27, bouncing is almost gone, most noticable in a corner when the weight is unloaded from either front wheel. May try 25 lbs tomorrow. I also took out some of the caster I had put in trying to cure the `death shake` I had before I went to cross steering. I haven't taken out any of that 3/8th inches of toe I worked in before I found that panhard bar loose. Steering seems a little loose, too much toe in? Sent from my SM-T580 using The H.A.M.B. mobile app
I'm arriving a little late to the party but have you tried a different set of tires? I built a '27 T roadster for my oldest a few years back and had a similar issue. After trying everything under the sun, I put on an old set of tires that I had run on my coupe and 'Ta Da". Instant fix. Now I use the old tires for mock up only. I can't tell you why but it worked.
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