This question is being asked of all those who have successfully solved problems the old fashioned way, with facts and figures, trial and error - not opinions and guestimates . My question is ultimately about front end wobble at a specific range of speed, but before I get into the details of that statement, you need to know some of the specifics of this particular car - its overall history, and what has been done or attempted to resolve this issue thus far.............. So, here goes This tale of woe begins life as a 1934 5 window coupe, and although not really a "Barn Find" per say, but "WHAT A FIND" for me! It is now a 3 owner car, I bought it from the second owner(s) who bought it from the original owner in 1975 and it was being used as daily transportation for him till he sold it in 75; I also have the original 1934 Kansas ***le. The car has NO rust, has never been hit, never been modified (till its restoration) fender beads are intact and have no cracks. The engine is a rebuilt 1935 LB with inserts - in 2014, rebuilt trans - 2015, rebuilt rear end - 2005, steering - brakes - suspension are all rebuilt over its second owners restoration. The car was restored (1975-91) over a 15+ year period to Hershey judging standards and was shown successfully for many years. Recently it had the newer engine done with Eddie Meyer heads, 97 carbs by Max, and other more modern up dates that make it road worthy and very pleasing to the eye. Yep, its modified - but not really a street rod. Here is where things start getting interesting; I've done steering boxes for model A's, F-100 trucks, 55/57 Chevies & Corvettes, and this one seems to be adjusted correctly with little to no play. Steering components (balls are round) are all tight, tie rods & drag link all feel tight, king pins & bushings are all tight and the bearings are in the correct locations and are also loaded properly - the wish bone ball is good and tight also. The wheels I am using are the bent 40 spoke Kelsey design; stock width up front and 6:00x16 tires mounted, the rears are widened to 7" and have 7:00x16 tires mounted. Prior to mounting things together, we went to the trouble of spin balancing the tires individually and the wheels individually to look for any weight corrections that could be made by mounting heavy & light weights opposite each other to cancel out some of the imbalance. All the tires have been balanced and rechecked, I have also tried another set of tires from another car that do not wobble on it but do on this one. We have a newly paved section of highway next to my home that has a posted speed limit of 45 - the road is so nice that you could feel the tires roll over a mouse turd . The car tracks well and does not change lanes, but when you approach about 28/29 mph the front end starts to do the death wobble; it feels like it is a loose wheel and it feels like it is from the RF more than the LF, but swapping the wheels side to side does nothing, also using the other set of wheels & tires has the same symptoms. I had friends follow the car from both sides and watching the front tires with binoculars to see if there were any visible signs of wobble at the leading or trailing edges of the tires (not the footprint or contact area) but they could not identify any issues when I told them at what point the wobble starts to happen at speed. I am not at witts end, hardly, but at the beginning of this frustrating and very confusing situation I have been presented with. I have restored many Corvettes & 55/57 Chevies over my lifetime and several Model A's, this one is just another challenge, of sorts . I would appreciate any and all suggestions you might have to offer. Lastly - once my son can spend some time with me and explain the details of posting pictures on the HAMB, I'll be doing a nice article on this magnificent 5 window coupe I was lucky enough to find by accident - No, it wasn't a 'Barn find' - but "What a Find" for me! Thanks, Steve
How about some info on caster and toe settings and tire pressures. Did you do a search on here? There must be a hundred threads about "death wobble" . Look at threads by **** Spadora, he knew what he was talking about.
What changes were made to the front end between the time the car didn't wobble and the time that it started to wobble? Look there for the solution. Worn kingpins, worn tie rod ends can also contribute to this problem. Also check for excess castor (more than 7 or 8 degrees) as this can contribute to the problem as well. The "death wobble" is often "triggered" by hitting a small bump or other irregularity when conditions are "just right" so it might not be consistent as to speed when it begins. I think minor out-of-round tires/wheels and slightly out of balance condition can act as triggers as well. Anything that can set off an uncontrolled oscillation - which is what "death wobble" really is - can be the trigger. I struggled with this problem with my coupester for a long time and checked everything thoroughly but the wobble persisted though it was more rare as each contributing factor was fixed or improved. I still run a lot of caster - probably too much - but can't fix that without major changes. After fixing everything I could I broke down and bought a Pete & Jakes front end damper. That has eliminated the wobble totally...so far. My theory is that the damper dulls the effects of the various triggers so they aren't able to start the oscillation. Good luck!
I had the wobble until I checked toe and it was way too "in". Adjusted it (to about 1/8") and has been fine since. Hope this helps.
I would still be su****ious of that wishbone ball. You can try putting a big flat washer in there and tightening it up and see what happens. Bet it goes away.
I second AVater's comments about the toe-in adjustments. I introduced the death wobble on my 49 F1 truck by accident. My steering link was bent down. One day I decided i'd fix it so I put a floor jack under it and "jacked" it back into shape. When I did this I inadvertently increased the toe-in of the truck(the steering link is behind the wheels, when I straightened the link it pushed the rear of the tires outward increasing the toe-in). I didn't realize it at first and didn't put 2 and 2 together that I all of a sudden had the death wobble. I spent the next month rebuilding the spring shackles, replacing tie rods, etc all to no avail. Finally I read something about the toe-in settings so I took a tape measure out and did a quick down and dirty measurement. Sure enough, too much toe-in. I adjusted the toe and have never had a problem since. Take a tape out and make a measurement. Good luck Bobby
Subscribed for the fireworks to come. My advice is to check for loose components, caster, camber and toe in. Try some type of dynamic balancing product in the tires like beads or powder.
Hello, We all had our versions of speed wobbles in unbalanced wheels and tires (along with out of alignment front ends) in our own cars. But, for the slightest bump or hole in the road, the alignment/balance gets out of shape. At the drags, even the top racers with too much initial power sometimes have the “shakes.” This is a low speed, power wobble, a relative to the high speed wobble. KS Pittman at Lions in 1964 during an elimination race against Big John Mazmanian. Jnaki
I need to do this check myself to get rid of a death wobble. How do you measure the toe? I can't use a tape measure on the front end at spindle height in my avatar car due to bodywork etc. The wobble occurs from 46 to mid 50's MPH. I can accelerate through it, but that's an unacceptable solution.
Last year I went through this on a 32 3 window that I helped build. About 300 yards into the first test ride with the owner, we hit a bump and got the wobble at about 15-20 mph. We went back, made sure everything was tight and lined up, seemed fine the next time we took it out. He called me a few days later and said it happened again in a different place. It was frustrating, because we could never reproduce it in the same spot. I read all the articles I could find regarding death wobble, including **** Spadaro's posts on the HAMB. I started with squaring the axles to the ch***is centerline. They were off a little bit. I drove the car quite a bit, it seemed to have fixed it, but after about 50 miles, it happened again. We tried toe in, toe out and zero toe, none made any difference. We tried putting on different wheels with radial tires, it didn't change anything. People kept telling him that the dropped Ford axle was worn out, so he bought a new dropped forged axle. Guess what? No change. The steering box was replaced with a new one, with no avail. I got tired of throwing new parts at it. To make a long story short, it turned out to be a caster issue. We had set it up at what we thought was 7 degrees when we welded the wishbones in place, thinking that was the magic number. That, combined with a wishbone that was slightly tweaked ended up giving 9 degrees on one side and 11 on the other when the springs settled. I cut and re-welded the ends of the wishbones set at 4 degrees with a digital level. The wobble never came back. I wanted to change the caster earlier, but "experts" kept insisting that it was something else. I did eventually install a steering stabilizer because I had already bought it for a last ditch effort. I decided I needed to fix the issue first, rather than band aid it. Dave
Spin the tyres with a piece of chalk to make a line around the cir***ference. Measure at the front, then measure at the back. Sent from my iPad using The H.A.M.B. mobile app
I'm subscribing, just in case yall find it. But I have a question for the OP: You state something to the effect that you tried the wheels and tires off another car, and that although they didn't wobble on the other car, they did wobble on yours, if I understood this statement. Do the tires and wheels you're running wobble also?
Try snugging the tie rod ends up a bit. Both the ball's taper into the arm, and then the plug pushing on the spring inside the rod end. Then grease them really good. Have you checked the shocks? Were they rebuilt when the car was restored? Do they leak? Are the shackles still tight? Are the nuts on the bottom of the perches tight? Can't tell by looking, you'll have to pull the cotter pins and give them a turn with a wrench. But, any dry rust dust is a great indicator of movement.
The Jalopy Journal
