I ran into a simlar issue when running GM discs, turned out that with steel wheels and the gm brakes, I had too much unsprung weight on the front end. It caused bouncing in the front end. Changed to skinny wheels and never had a problem after.
what type of wheels.are they hub centric.were they mounted for balancing using the wheel center or stud holes.
The front wheels are weld rodlites. I don't think weight is the problem. I'm going to change tire pressures tomorrow and reset the toe in a bit. Put shocks on today and didn't change anything. The tie rod is in front.
Let's be sure we are talking about the same thing here. When you say "wheel hop" do you mean they are bouncing straight up and down like a basketball, or do you mean they violently shake from side to side, like a shopping cart caster wheel when they start wobbling ? If they are bouncing straight up and down it is because the shocks are not dampening out that bouncing, or the tires are out of round and start hopping. If they are wobbling side to side, that is death wobble, a whole different animal with other fixes. Before I took my 27 to the BP drags I went to an old school truck tire shop and had my front end spun on a balancer that does everything that rotates. They could have also shaved my tires to take off the high spots if they found that problem, but the didn't. The spin balancing made a WORLD of difference that I could feel in the steering wheel, and even at 90+ mph it was smooth. Here is the kind of balancer I am talking about. Also, post a few pictues of your buddies car so we can see what we are dealing with. Don
Don, Funny thing, my friend with the bucket has a wheel balancer just like yours in the picture. He just doesn't know how to use the balancer. I don't either. I called him a few minutes ago and told him to find some one who can. I haven't driven his car for a test, he does. He says wheel hop up and down. I'm going to drive it tomorrow. He may have wobble instead of hop and doesn't know the difference.
I'm thinking it is really death wobble as opposed to wheel bounce, that is the most common complaint. I just read your entire thread and noticed you say it is running GM discs, that could be a problem there. When we built my Son's T bucket I had a complete chrome front end that had GM discs on it, so I gave it to him to use. When we got the car running it had severe death wobble. I spoke to Mickey Luria at Turkey Run (the guy who owned Total Performance) and he said "You are not going to like those GM discs, they will make the front end death wobble because of too much rotating m***." We bought a set of lightweight Wilwoods and pulled the GM discs off, did a few other adjustments, and no more death wobble. Also, if your tie rod is behind the axle buy a SoCal steering stabilizer and install it. They sell for $40 or $80 in chrome, and I will never build another car without one. The difference is night and day. My 27 never had DW, but the stabilizer firmed up the front end to where I can go over RR tracks and potholes with not even a whisper of shake. All 4 of our cars are running them and my Sons have noticed a real difference in theirs too. Some people scoff and call them a bandaid, but I call them a great addition to any straight axle car. Don Here is the stabilizer on my 27.
The tie rod being in front of the axle is a poor design. Most bucket T's handle poorly with this design. The Ackermen theory is usually ignored and handling is not only poor on curves but also going straight on bumps. This theory is usually disputed by novices and I am sure there are some on this post that will deny this is the problem. The theory is the straight line from the king pin p***ing over the center of the tie rod end should end at the center of the rear end. Just take a string and hold it on the king pin and pull it tight at the center of the rear end. The string should go over the top of the center of tie rod. I talked to a lot bucket owners and rat rod owners and all of them with the tie rod in front of the axle have some kind of steering problem. Some reply that they have seen this step up on lots of cars and have built hundreds of cars with this set up and have never had a problem which will be the response to this post.
Its 4 years old with 60K miles on it. As for "bounce and shock absorbers".... no fenders, you can watch the wheel movement vs body movement at 80mph on the highway, the shocks are working. Take a car dolly, run the tires low and run them max and tell me which bounces higher. I played with the tire pressure up and down and this is what worked for this car. Wasnt asking for advice as my truck isn't bouncing and has the milage to show its working
I agree that its a poor design no turns as that is the whole concept of the theory, but PLEASE enlighten us on how it affects a straight line, even with straight up and down bumps.
I'd swap wheels and tires just to confirm or deny the most likely culprit. Posted from the TJJ App for iPhone & iPad
Quote:I agree that its a poor design no turns as that is the whole concept of the theory, but PLEASE enlighten us on how it affects a straight line, even with straight up and down bumps. I wondered about that one too. No question that in the perfect world it is better to put the tie rod behind, however, due to things like a suicide front end you are sometimes forced to put it out front because too much stuff is in the way, like springs, frame, headlights, etc. My 23 had it out front, and the ONLY issue was a slight scrubbing when turning sharply, like into a parking spot. Aside from that it went right down the road and handled well. Would I have preferred to have it behind ? Sure, but no matter how I looked at it the tie rod would never fit back there. Don
Front or rear makes no difference even on turns as long as you get the tie rod centers out far enough to still intersect that line. I'm curious to see the answer on how it affects it on a straight line.
Unless I am really forgetful, this shot is not of a wheel being balanced, just spun. I used a balancer like this in the 60's when I was still in a dealership and there was a plate like affair that clamped into the rim , it had several small knobs in the center that you held one after the other to rotate weights around the inside of the plate till there was no vibration in the wheel and tire . The device then had a reading as to how much weight and where to place it. I have never understood why it was felt better to balance tires off the car as they do today.
My friends tie rod is in front. Only problem with it is dogs, deer, hogs or whatever else is in the road. LOL The Ackerman theory is right on. I'm very familiar with it. Have changed tires both front and back. Still wondering though if my friend knows the difference in hop and wobble. Toe in or out can definitely make it wobble. Hop ,I don't know. Gonna play with tire pressures tomorrow plus change the toe in. My friend bought the bucket as a pretty rough project and is just trying to get it to drive properly so he can do some cosmetic work. Thanks to all who suggested help. It's all appreciated.
I read the responses in this thread and I have a question and an observation:Are you running radial tires on the front and bias plys on the rear? No one seems to have posed this question and I can say from personal experience that this can cause some really serious handling problems.I had this happen on a V-8 Pinto wagon I built some years ago.Put a set of bias ply snow tires on the rear for winter running and drove about 1/4 of a mile before turning around and heading back to the shop to remove them.Not only was I experiencing what felt like wheel hop but the swaying was literally uncontrollable.
Don't worry about how to use the balancer right now. But do jack the car up with the floor jack in the middle of the axle and use the motor part to spin the front tires one at a time. That will tell you if the vibration is in the wheels and hubs. Then you can go about figuring out how to fix it. If they spin up and the car doesn't shake you have a different problem not related to the wheels and hubs. If the balancer is a hunter it most likely has some adapters that fasten inside the rim of the wheel. Then there is a hub ***embly that fastens on the adapter. You work the rings on the hub with your fingers to get the right weight in the right location on the wheel. it's an absolute must that the adapter be tight on the rim and both arms are turned to tighten it . There are cases where the hub and adapter have taken off across the shop when they weren't installed right. The other style uses a strobe and a sensor that sticks to the bottom of the car with a magnet. if it is working right it is fantastic as you are spinning only the wheel and hub with no added pieces and the gauge on the strobe shows how much the wheel is out of balance and the flash of the strobe shows the wheel with the light spot to the top. The main thing right now is use the motor of the balancer to spin the wheels up to see if the vibration is in the wheels and or the hubs. don't stick anything on it just spin the tires up. Make sure there is no gravel in the tread as it tends to fly out at speed. If you decide to try using the balancer to balance the tires you are welcome to pm me and I'll pm my cell number back and I can walk you through it on the phone.
You said earlier that the toe in is correct. What is it set at ? Every car is different, some like toe in, some actually like toe out. Also, where on the tire are you measuring your toe in ? Don
Greetings I had the same problem with a lakes modified, using Chrysler rotors, steel wheels, bias ply 16" tires. The car was ***embled from a kit. What I experienced was hop on one left front wheel. 1) rebalanced tires; 2) replaced front tubes; 3) took front wheels off and reversed left to right and right to left; 4) replaced front bias ply tires; 5) took tires off wheels and was preparing to reverse tires to wheels when I noticed tie rim stamping different than other (called mfg and found that the rim was not manufactured for highway use); 6) replaced that wheel with a new and replaceent (much better); 7) also during this search, I became aware of hub vs lug centric wheels. I'd suggest determining the right method of balancing the wheel in question. Good luck with your search for a cure. Jack
Find a shop in your area with an old tire shaver. If they are bias ply they are out of round guaranteed.
Pictures'd be nice.... Have you checked the toe on the rearend? Could have been bent from the junkyard or warped it welding brackets on. How are you measuring toe? Bomb can around the cir***ferance and then marking with a scribe? Measuring tread to tread you might as well guess. I had a board with a nail in it for the longest time, if you don't have an actual tire scribe. Have you checked the rear housings squareness in relationship to the centerline of the ch***is? Just because the WB's only off an 1/8 doesn't mean the axles are anywhere close to parallel to one another. I'd start at the rear because they're bigger, have more traction, and the description coupled with the fact that normal fixes don't seem to have any effect makes me think it's possible the rear's are trying to push the fronts sideways till they hop. I'm going to watch what fixes this, don't just let this thread die.
My lightweight bias tire shod roadster had the same issue. Checked EVERYTHING. Running no panard bar. Had the front tires trued (shaved). Man what a difference that made! Cost me $85 bucks but it was money well spent. No more hop and can SAFELY drive above 70 MPH without the death grip.
i got a fairly new build model A with what seems to be the same problem it will death wobble every now and then specially after a set of tracks,, but it wheelhops the right side almost all the time at speeds over 50 i spinbalanced the fronts and it got better but didnt go away im bringing it to an alignment guy here who builds rods and seems to be the go to guy for straight axel front ends hes gonna check out everything and let me know whats going on
If you can't find a tire shaver in your area you might try clocking the tires on the rim. Break the bead and clock them a quarter turn on the rim. See if it gets better. Then try another quarter turn and so on until you see any improvement. Maybe try clocking them on the drum one lug at a time and see if you get any improvement. A lot of trouble I know and I don't put much faith in the outcome. I'd just try calling around and see if you can find someone to shave them. The last set of Bias ply tires I put on my roadster I just took them down to the shop that does my shaving and had him do it before I even tried them. Smooth as gl*** at 80+. Most of his shaving now comes from race cars.
Put some Coker tires on it, and index the the high spot on the tires with the low spot on the rest of the rotating ***embly, and see it that helps.
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