Death Wobble

[Lenny Bruce]

Good morning all! So I took my ‘30 Tudor for a slow ride around the block few times since I bought it. Last ride I was close to home driving down hill and here she goes…Death wobble! I jacked up the front end the king pins seem nice and tight as well as the other front end components. Steering is nice and responsive not much play but I did find the front wheel bearings are worn and one of the race was completely loose. The tires are horrible hence the short trip to test a few things. Can the wheel bearing’s and race cause the wobble or should I dig deeper in the front end?

[Patrick L.]

Anything that is loose or not adjusted correctly can cause it. That is, anything from the steering box all the way thru to the wheel bearings and anything in between.

[Rob Doe]

Check the toe in first. It is a primary source of wobble, and it is not difficult to do.

[WHN]

Fix the bearings and tires. Then go for another drive. Anything that is loose in your front end will contribute to a car shimming.

Enjoy.

[larrys40]

Look for loose hub races as well within the hub. Remove the front hub from the spindle and see if the outer race turns at all with your fingers . If it does the hub is enlarged and you will need a new one.
Lots of things to check but it is important to ensure that all components are tight and up to standards.
Here’s a quick list .

1. Spring not sagged , has gap between axle and bottom of spring
2. Steering at center check to see if there is more than and inch play at wheel.
Is pitman arm tight , if steering arm plugs are screwed in pst outer edge there is probably worn components, steering balls and internal cap and springs on the tied rod and drag link
3. Steering box itself , adjustment and/or worn
4. Make sure it has original style steel radius cap assembly, not rubber ball

5. Spring clamp bolts tight!!
6. Front brake issues ?
7. Check toe in after verifying all above and correcting
Set to in to 1/16 .


Top issues above that cause issues. Once resolved will be a different car.
Larry Shepard

[CatMan1]

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Originally Posted by Rob Doe

Check the toe in first. It is a primary source of wobble, and it is not difficult to do.

I second this! I bought the tool and got it aligned. It fixed it.....but for some reason it came back. Not as bad, but it did. Maybe I didn't tighten something back up?

[bruceincam]

Originally Posted by Rob Doe

Check the toe in first. It is a primary source of wobble, and it is not difficult to do.

And then buy new tires and fix the wheel bearings.

[Terry, NJ]

When the king pins and the spring bolt bushings seem tight, go to your steering balls. They're supposed to be 1.000" all around. Some are so flattened out it's hard to believe that they were ever balls. Chasing down "Death wobble" can be a frustrating experience!
Terry

[katy]

Originally Posted by larrys40

Look for loose hub races as well within the hub. Remove the front hub from the spindle and see if the outer race turns at all with your fingers . If it does the hub is enlarged and you will need a new one.
Lots of things to check but it is important to ensure that all components are tight and up to standards.
Here’s a quick list .

1. Spring not sagged , has gap between axle and bottom of spring
2. Steering at center check to see if there is more than and inch play at wheel.
Is pitman arm tight , if steering arm plugs are screwed in pst outer edge there is probably worn components, steering balls and internal cap and springs on the tied rod and drag link
3. Steering box itself , adjustment and/or worn
4. Make sure it has original style steel radius cap assembly, not rubber ball

5. Spring clamp bolts tight!!
6. Front brake issues ?
7. Check toe in after verifying all above and correcting
Set to in to 1/16 .

Top issues above that cause issues. Once resolved will be a different car.
Larry Shepard

Also check the front spring shackles.

[Patrick L.]

Yep, once the front end is nice and tight, set the toe-in to 1/32-1/16".

If a bearing fits loose in hub or over spindle, 2 small prick punches in line and spaced at 90* from each row [ 8 total] will tighten and center them. Thats an old Ford trick that I didn't agree with until the factory rep convinced me to do it. I was just a kid at the time and that trick worked. Many many new Fords came thru with that issue. Did it a number of times after that.

[Jim Brierley]

I've found the drag link and tie rod ends to be the most troublesome. Everything must be tight!

[Terry, NJ]

Originally Posted by Patrick L.

Yep, once the front end is nice and tight, set the toe-in to 1/32-1/16".

If a bearing fits loose in hub or over spindle, 2 small prick punches in line and spaced at 90* from each row [ 8 total] will tighten and center them. Thats an old Ford trick that I didn't agree with until the factory rep convinced me to do it. I was just a kid at the time and that trick worked. Many many new Fords came thru with that issue. Did it a number of times after that.

Patrick, That's called "Staking" in the machine trades. I taught an A & P how to do it and from then on, many a nose wheel of a C152 or C 172 got repaired that way rather than putting out $ 400+ for a new wheel . Never had a bad landing from it.
Terry

[Lenny Bruce]

Awesome thanks everyone I’ll get at it!

[Patrick L.]

Originally Posted by Terry, NJ

Patrick, That's called "Staking" in the machine trades. I taught an A & P how to do it and from then on, many a nose wheel of a C152 or C 172 got repaired that way rather than putting out $ 400+ for a new wheel . Never had a bad landing from it.
Terry

Yep !

Did it to a c150 a couple decades ago. Some folks were complaining about the shimmy, just told them to keep the weight off the nose.

"Never had a bad landing from it" Good. Keep the weight on the mains.

There are other times when it comes in handy. Some folks like to argue that its not a quality fix. I thought the same until our Ford rep convinced me otherwise.

[nkaminar]

There was a guy on the forum a while back with the same problem. It turned out to be a bad ball/fitting at the end of the radius arms, where it mounts to the bottom of the bell housing.

[J Franklin]

Don't forget to oil the spring and grease the shackles.

[Rob Doe]

Originally Posted by CatMan1

I second this! I bought the tool and got it aligned. It fixed it.....but for some reason it came back. Not as bad, but it did. Maybe I didn't tighten something back up?

CatMan1, remember to push the front of the wheels outward with your hands to remove any slack before using the tool to set the tow in. I saw a youtube video the other day, and caught a glimpse of an elderly gentleman that had two wooden blocks and a straight edge against the outside of the tires on each side of a Model A. He was checking the front wheel alignment. I used this technique to check the alignment of my sport biplane's main landing gear 20+ years ago.

Guys, there is a section regarding the front end geometry of an early auto, (Model A) in the Dyke's Encyclopedia of Automobiles and Gasoline Engines. My version is the 1948 release of this book. It explains front end wobble far better than I can type in. In fact, a copy of this book will open a whole new world of understanding to even the most experienced mechanics on a number of topics.

So much to learn...I need at least 5 more lifetimes...

[Rob Doe]

Originally Posted by bruceincam

And then buy new tires and fix the wheel bearings.

Yep, tires soon. Also found shock arms were loose and theiry setting was incorrect for the temperatures. (Bratton's sealed repro shocks) Tires are old, but no signs of failure, probably stiff as heck and out of balance. Out of balance can cause wobble due to front end geometry (inclination) as I recall. Our coupe does not have the death wobble, but does have wheel bounce and a slight wobble between 40-45mph. Above 45 it actually smooths out.

The car's tire and wheels are less than 1/8th inch when tested with a stationary pointer front to rear and 90 degrees, side to side. I put 5 oz of antifreeze in the tubes, but it has had little effect. As I said, tires and tubes soon.

[Rob Doe]

Originally Posted by nkaminar

There was a guy on the forum a while back with the same problem. It turned out to be a bad ball/fitting at the end of the radius arms, where it mounts to the bottom of the bell housing.

Good one Neil. I still need to drop the ball down and measure it.

[katy]

Originally Posted by Rob Doe

I put 5 oz of antifreeze in the tubes, but it has had little effect.

What's the anti-freeze supposed to do?