Technical Need help/suggestions - '34 Ford front end trouble

Hello y’all…I need a few corrective suggestions on my ’34 Ford hot rod.

Here’s what she’s got: Dropped front axle, tube shocks, drum brakes, stock ’34 steering box-rebuilt a few years back by Josh Mills, toe out set at 1/8”.


Now, here’s the problem. Sometimes, hitting a pothole, or crossing railroad tracks, the front end goes into ’convulsions’…the wheels start flopping from side to side and it shakes the whole car. The only way to stop it is to slow the car speed down until they get back under control and then it rolls/drives fine.


I’m sure I’m not the only person this has ever happened to, so I’m pickin some brains here…what have you tried and what has fixed it?...or. heck, what would you do?


Thanks for any serious answer…

 

Should be 1/16 to 3/32" toe in. Eighth inch toe out is asking for trouble.

 

Are your steering arms cast as part of the spindle, or bolt on?My Model A did the same thing. It was the Speedway steering arms, the bolts holding them to the spindles had loosened off, in spite of Loctite. I corrected it by replacing them with So-Cal's which are through fastening (Allen bolt & stover nut), as opposed to Speedway which uses a "blind" hole. Not putting down or plugging anyone's goods, just sayin'.

 

I had death wobble on my rpu. Too much toe in. Adjusted to 1/4” in and immediately fixed it. Previously was closer to 1/2” in when I had the death wobble.

 

Make sure theres no play in the front end....king pins,rod ends,spring shackles.Check the front hubs for loose bearings.You may need a pan hard rod,or a solid spring perch on the drivers side.They fight bump steer.

 

Well ideal toe in is based on tread contact patch and wheel off set. I know that's controversial but,,, toe out is not. You have also not mentioned how much Caster you have and that's a larger contributor to your issue. My advice is go to a good alignment shop and have them give it a once over. These are not things you can do right with a tape measure and a protractor. Key board advice is generally only good to get you doing something but seldom what it takes to correct what is often a simple issue in the right hands.

 

After over 10 years of fighting the "death wobble" on my '32, IU finally found the FIX.
First of all, my set-up was similar to yours. TCI dropped axle, Mustang box with drag link to the spindle.
After probably 20 times on an alignment machine, the best set-up was:
6 degrees pos. caster
1/16 tow OUT (learned the "tow out trick" from the T Bucket guys).

These settings ALMOST got rid of the death wobble...but every once in a while....

The "fix" that solved the problem was adding a SoCal Steering Dampner! Not only did it completely eliminate the death wobble (2 years now) it also got rid of that annoying "bump steer" you get with drag link to spindle steering.

Incidentally, with 1/16 tow out, you end up "chasing" the steering somewhat so I backed it off to 1/32 tow out and still no problems.

Hope this helps

 

I didn't get into camber and spindle inclination because us "solid axle guys" are stuck with what we got. It's "built in" to whatever axle we are running. Admittedly spindle inclination VS tread patch can be addressed with rim offsets and tire widths but the only real adjustments we have is caster and tow in/out.

 

I'm not here to argue Jack, but i have never heard of a car deliberately set up with toe out. really, the t bucket guys do that?

 

A panhard bar cured the last one I worked on.

 

All the parts must be tight and in good condition. Its' imperative the tires be balanced. Caster is important. I used a Welder's Series flat crossmember in mine, set at 7 degrees. I tried using a tape measure to set my toe in at 1/16th and just could not get it close enough so I took it to work and had the guys put it on the rack.....they set it for me. Every once in a while at a certain speed, mine will oscillate a little. I attribute it to an out of round wheel on the right front that also has a bit of run-out. Even with dyna beads it will occasionally wobble [35 mph] but if I speed up or slow down it pulls out of it.
I have a new set of wheels that I'm sure will cure that last little wobble. Dyna beads really helped mine.

 

Not here to argue either. Just pointing out what worked for me.

When I first encountered the death wobble, (which is so violent it rips the steering wheel out of your hands) I searched the internet for ANYTHING that would help. Found mostly just 4X4 info but I did find that some T Bucket guys with those skinny Hallcraft & Dayton wire wheels would use tow out to "calm down" their front end. I was desperate so I tried a little tow out....and son of a bitch, it worked.

Keep in mind this was a brand new complete TCI frontend with no worn out parts...and even changed the brass bushing kingpins to the bearing type (which made it worse).

I know, tow-out doesn't make any sense...it goes against everything we were taught about front end geometry. But unless you have experienced a death wobble shaking your car so violently you can't control it, you'll try anything.

 

When thinking about Toe Out all that comes to mind is the Plowing effect that has to be happening and that under a load it just can't shake so it appears to be working. But then I'm with you, if it works "it works". The fact that someone else's also works and it's done different does that matter? Is there such a thing as works better?

 

I have fixed death wobble on about a dozen 4x4 rigs, with toe OUT.

 

Yes, that works both on front wheel drive vehicles and 4x4s too, but not on rear wheel drive cars. I figure his 34 would be rwd, hahaha
The torque applied to the front tires on both 4x4 and fwd cars tends to pull the tires " toe in" under load, therefore they usually have a slight toe out setup. I learned that the hard way when I had my 56 Chevy at an alignment shop and they usually did VWs and Audis... drove like sh*t. I set it at 1/8" toe in and it was perfect. That also happened to a 40 Ford, and a buddy´s Camaro. They were at the same shop

 

Measure the wheelbase on both sides of the car to be sure it's the same

 

Is the death wobble a new problem that showed up? If it’s new problem what did you recently change? What part is now worn past it’s useful life?

Toe adjustment and scrub radius do go hand in hand.

 

4x4 with the transfer case disengaged is RWD.

I have used this on early Fords, too.

 

Shackle angle can get you in trouble to 45 degrees seams to work best. Shackles at 90 degrees without a panhard bar will allow the axle to move side to side in relationship to the car on a cross spring.

 

I have always set the caster at 7° and 1/16" toe out, I have never experienced any problems. HRP

 

Thanks to all for the suggestions. I'm saving them in a file so I will have them when I try to resolve this. Just to answer a couple of questions- It's not a 'new' problem. It has acted this way ever since I dropped the axle and split the 'bones. I'm running wire wheels and radials. Life keeps me away from the board at times, but I thank you all !!!

 

Had a similar issue one time that was solved by a number of little things. The last thing on the list was a good tip that I never would have thought to do. Make sure that both cross taper pins (the tapered bolts that hold the king pins in place) are fully inserted (or close anyway). I hammer them in with a drift then tighten the nut, instead of tightening the nut to pull them in with the risk of snapping the pin... I thought mine were already tight, but I sunk them further and it did make a difference.