Hot Rods issue to cause a death Wobble

I,m working on this issue myself reach 50 mph and hang on ... sounds weirded but could it be a loose or not tighten properly wheel bearing Gene in Mn

 

What car are you working on, what's the steering and front suspension setup? Do you have photos of your setup so people can help you troubleshoot?

 

Sure it could. Or maybe not.

 

You pretty much should go over everything and make sure that everything is tight and right.
After all you don’t want to be the lose nut…

 

Assuming all tires are same size, switch , front to back. Try again.

Ben

 

Do a HAMB search for "death wobble"...the subject has been covered many times.

 

Yes or No Maybe
When Asking for solutions it is important to include any and all facts about the events and history of this problem.
Details matter

 

Many things can contribute to death wobble, and the entire front steering setup needs to be looked at for correct toe in and wear of components. As was mentioned, you really need to give us info on what front suspension system you have to help determine direction.

 

Camber or the lack of can be an influence also.

 

Did a Hamb search as you mentioned Yup you are right many many inquiries my car Model A, beam axle w. new new components checked and rechecked,steering box, new tires on
smoothy rimes
One thing I noticed working in a tire shop is how may new times are not round
One other thing I am running very large tires and wheels on the back Could that be contribute Gene

 

Check caster.

 

What’s the caster, what toe in, did you use real rod ends or heims, what steering, any panhard, what shocks, radials or bias? As you can see, we don’t have your information.

 

check toe in-out... putting way bigger tires on the rear might have wiped out all the caster.. then you will need to either shim the whish bone or split it ... zero caster with toe issue will cause the wobble

 

My experience with "death wobble", and virtually everything I've seen/read is that it occurs at speeds well below 50 mph...more like 15-30 mph when you hit an uneven bump in the road, causing a vibration so violent that it rips the steering wheel out of your hands.
What you are encountering sounds more like a severe vibration (bad tire, bent rim) that shows up at 50 mph.

If it happens every time you hit 50 mph its not a death wobble...they only happen occasionally.

 

This topic has been beat to death on here! But, first, make sure your tires are round and balanced, one of the biggest causes! Then make sure all your suspension is tight, then check your alignment! I assume you have a straight axle? If all of this checks out, change your castor a degree or two!





Bones

 

You have shocks on the front?

 

Hello,

In our 327 powered 1940 Ford Sedan Delivery, it was a definite project car when we bought it. My wife and I were so happy that we initially overlooked a lot of problems in driving, handling and braking. But, after we got the sedan delivery home to our little apartment, we looked for what could cause the shaking at freeway speeds. It got worse as we got up to 60-70, so yes, it was 45-50 all the way home in the slow lane, then off of the freeway as soon as possible to drive on the side roads. Now, it was not as noticeable. ha!

But, once home, my wife took it for a drive down PCH for a test. She got about 20 miles and had to turn around. The road bumps were bad enough, but now, it was shaking at around 50. It stopped, but the pedal was long. And when she went around corners, it was strange in tire grip, etc. they were off brand tires, not the big name brands.

So, I tried my best to get the front end parts that looked worn out replaced and repaired if needed. It got a little better, but still not the best. It took a while, but finally, the scope was beyond my means. Luckily, our friend who had a shop about 30 miles away had always handled our wheel balance and alignment with some accessory front end work if necessary, on our 58 Impala and 65 El Camino. Yes, it was a drive to get from Long Beach to the Culver City/Westwood neighborhood.

I even replaced the old lever arm shocks thinking the new vertical shocks were better. They were, but it was not the problem. The new shop had all of the latest wheel mounting, balancing and front end alignment mechanics and machines. But, the tire shaving place was down the street.

I remember back when I was going to college and then I needed a new set of tires after several years, his recommendation was to get the tires shaved first, then the short drive to his alignment shop to get the full treatment. He had done our 58 Impala many times from the time my brother owned it and it was my high school racer/cruiser. It was not the suspension replacement, as it was fairly new. So, he did his thing after insisting we get our 4 tires shaved first.

People thought we were crazy when I told them of the story of the rubber that lay on the ground below the tire shaving machine. 4 new Firestones, then 4 Inglewood Posatraction tires and a set of Goodyears, as the years progressed. The time between the set of new tires shaved was a lot longer than when my brother just had his 51 olds balanced and aligned with his first set of tires. After his second set, we met our friend with the wheel shop and the tire shaving procedure.

When he got finished with all of our cars, we were totally impressed at whatever speed the Impala, the El Camino and the 327 powered 40 Ford Sedan Delivery could drive and corner, without any drifting and shakes. On the freeway home, it was as if I was gripping the road, but the ride was straight and smooth. I normally drive about the same speed as others and it is part of going with the flow. One selected lane and that was it for the long haul. No lane changing back and forth. It was all about the road ahead and what to expect. We had been driving on these freeways since they were developed and open for everyone.

What the tire shaving guy had done was to have our tires shaved to correct roundness. It left a ton of black rubber on the floor. But, as the wheel spun after finishing, the pinpoint shaver did not carve any more off of the tread. When he put on the next tire, as he manually spun the tire, the tire rolled about ½ way around and stopped at the shaver blade as a bump was on the “round” tire.

He manually backed it up and began the tire spinning again, with a little shaping starting and as the tire spun, more came off of the bump and finally, it started shaving the rest of the tire for a few spins. Now, the tire was round and needed balancing on the rim.

Jnaki

At first sight when he did that same process to our new firestones, it definitely was disheartening, but a necessity to get the so called round tires… correctly round shaped tires, as they should have been from the dealer or manufacturer.

When all four tires were shaved and now “round,” the rest of the wheel spinning for balance and once attached to the car, aligned to the specifics.

Our wheel and alignment guy said the tube shocks were a better alternative to the lever shocks. But, that his repairing, replacing the suspension parts all combined to get rid of the shakes at 50 or above. That included the tire shaving as a main part of the whole process. It was something that had to be done, first.

He also did one last check by spinning on the on the car old tire spinning, portable, moveable machine leaning against the tire on the car. As he spun the front wheels, no noticeable shakes or shimmy was noted. He did not have to make any other front end adjustments and the 40 Ford Sedan Delivery rode so nicely home that it almost was like no hands steering on the straight freeway surfaces.

Now, no shimmy or shakes beyond 50 +. When we were on the Coast Highway, the open road was made for long distance highway speeds. It was enjoyable to have a set of tires and a car all in line for a pleasurable drive at any speed. Shave tires, balance to specifics, repair or replace suspension parts and align the front end is the preferred method to get the 50+ mph shakes to go away. Try it, you will definitely like it.

Note:

There are a lot of folks that look at a tire and say it is round. They do not go through the tire shaving process. So, that is their choice. But, with all of the hot rod suspension maladies, one needs to take into account, new replacement suspension parts are necessary and also a great person who can shave, balance and align your hot rod. Start with the tires, tire shaving, and suspension. YRMV

If you are one of those that cannot do all of the suspension parts replacements, have a pro shop do the work. But, on later model cars, check everything first and most likely, it is the “out of round” tires that look normal, handle at low speeds and work like crap above 45-50 mph.

 

whats beat to death is people telling others it's beat to death... not all situations are the same, and some like to tell theirs...@hotrodjack33 did a nice post with another view... hard to fix stuff on the internet... but throwing things to check sure is helpful

 

Death wobble is usually with a straight axle! And there is a procedure to find the problem! Having many straight axles on the ranch and maintaining a fleet of straight axles for 33 years , plus many friends that have them, I have had quite a bit of experience with the problem!
I have “ fixed “ many “ unfixable” problems over my fifty plus years of dealing with this problem!
I am just sharing my experiences, people can take or leave the info! Makes no difference to me!



Bones

 

Had similar low speed wobble on the 27, after all the typical “ fixes “ found out it had a bent spindle, hard to see from above, easy to see in a pit.

 

In a word, yes.

 

Yes, it has.

But perhaps never as elegantly as this:
https://www.jalopyjournal.com/forum/threads/stell-got-my-deth-wobbel.470139/

Cheers,
Harv

 

Stock steering setup?

 

You would have to have some extremely tall rear tires to "wipe out all the caster".
On a 103" wheel base Model A it takes a tire diameter increase of 4" to change the caster by around 1.1 degrees.
Just for shits and giggles, that would be about an 18" increase in diameter to lose 5 degrees of caster......

 

Thanks for doing the math, and debunking one of the silly claims repeated often on the internet.

Our of curiosity I ran more numbers. Changing from say a 26" tall rear tire to a 31" tall tire on a Model A would net a 1.4° reduction in caster. If you also went to a 4" shorter front tire at the same time, you'd get a 2.5° change.

 

Want to thank all of you with my issue of the wild shake and the lack of the info required to help with getting the answer from me. With all the answers I think you hit it right...
1929 Model A Coupe fenderless SBC 350 TH - Chrome Solid Axle Drop Beam- 7 inch Rear/ Vega steering box Mostly built by a 80 yr old guy that being me...Drum in the back and disk in the front All new parts

Cause of the wobble Front and back tires sizes ( too different in dia) & height

front Radial 165 R 15 86S F-560
Rear Radial 235/75R 15 Back tire way too tall and dia

Gene in Mn