The Ford Barn

rob63mess · 04-18-2015, 04:24 PM

We were taking the roadster to dinner tonite and she was purring right along....I even commented to the wife how well it was running and how I was a mechanical genius and all

. We turned a corner and began to accelerate, we must have been going about 20 mph and the car began to wobble violently....I thought I has a flat tire for sure. I pulled into a parking lot and all tires were ok....the wheels were tight. I checked everything out and headed for home. It ran fine.... tried everything I could to try to duplicate the problem but it ran and acted great no matter what I did....any ideas?

Bob C · 04-18-2015, 04:27 PM

Do a search for Death Wobble. You need to check the
whole front suspension for loose or worn parts.

Bob

Walt Dupont--Me. · 04-18-2015, 04:42 PM

Tighten the tie rod and the drag like ends, when I first built 31 A, all new stuff, when I too corner on to another street, it went into that death wobble, I screwed the ends in until they bottoms and backed them out about one turn, I put many miles on in the last 19yr's and never had a wobble since. Also make sure you have enough caster. Walt

Goldhardt · 04-18-2015, 05:02 PM

Have someone turn the wheel back and forth with you underneath. You may find stuff moving that shouldn't be. That may at least get you started in the right direction. My buddy had the same thing happen to him. The shaft that the pitman arm attaches to was not secured where it passed through the frame. The nuts were only finger tight! His was a very minor fix. You may get lucky as well!

HoarseWhisperer · 04-18-2015, 05:11 PM

Any chance you have a worn after-market rubber ball modification on the radius ball?

Patrick L. · 04-18-2015, 05:17 PM

Sponsored Links (Register now to hide all advertisements)

Something in the front end is loose. Start at one end work your way completely through it, from wheel bearing adjustment all the way back through to the steering box adjustment and everything in between including radius rod.

RUNNERBUN · 04-18-2015, 06:47 PM

The death wobble can be caused by any of the following:
Loose and worn ball joints
Pitman arm loose on he sector shaft
Loose wheel bearings
Worn king pin and bushes (also check the cotter pin that fixes the king pin to the axle)
Castor (worn radius ball will effect your castor)
toe-in
wear in the steering worm and sector gears
or a combination of any of the above.

I have not experienced it in the A, but did have the problem in my Model T. It always happened at low speed at around 20 mph. Applying the breaks made it worse. If I felt it coming on I gave steering a quick hard pull to the right and left and the wobble would stop. Not suggesting this procedure as a permanent fix.
For your and everyone elses safety you need to fix the cause.

BILL WILLIAMSON · 04-18-2015, 08:59 PM

The MOST COMMON cause for SHIMMY, is too much slack in the STEERING GEARBOX!
Bill W.

Terry, NJ · 04-19-2015, 09:34 AM

It's best to go over the front end completely when the "Death Wobble" strikes. Jack up the driver's side and check the pitman arm and drag link ball for out of roundness. How loose are the wheels?loose Wheel bearings have been known to cause it too. How much slop is there in the king pin? Is there too much play in the steering wheel?Another giveaway is can you shake one wheel and have the other not move? The next thing is a little hard to find but It was a cause in my coupe. The spring shackle bushings! Mine were shot (both sides) and the whole front axle assy was shaking around. The is can be hard to find because when the car is at rest, the springs will feel solid, Note if the"eye' of the spring is touching the front axle. as Bill said, the steering box may need adjustment. There are four adjustments BUT they must be done in sequence and I don't recall what that sequence is.
Terry

BILL WILLIAMSON · 04-19-2015, 10:21 AM

OLDER Datsun & Toyota pickups were common or this, when they had a little too much worm & sector clearance, easily corrected by adjusting the screw & locknut! With steering in the straight ahead position, I'd just screw it down, SLIGHTLY firm with a screwdriver & back it OFF 1/8 turn. Regular old shimmy, the kind you have to stop, to get it under control, is usually caused by UNUSUAL undulations in road surface. Vermin's shimmy always happened in front of Bill Jones' house, it was caused by a loose rear drag link! He had ALL new parts, by the previous owner, BUT, the re-pro spring was TOO SHORT! The loading of the parts in the rear drag link end, Is also DIFERENT FROM ALL THE OTHER ENDS!! Some parts catalogs show this difference.
Bill W.
Bill W.

t farr · 04-19-2015, 03:28 PM

I had very bad death wobble and getting worse. We fixed all the mechanical problems and some that didn't matter. Seems I was trying to get the last bit of rubber off my tyres before I replaced them. Finally did that and not a sign of the wobble since. Silly Boy.

rocket1 · 04-19-2015, 04:09 PM

you should have knocked on wood when you made the remark about how well the car was running

grumpyoldsman · 04-19-2015, 04:19 PM

first thing never say its running .great because it wont for long. next time you go where you were run over the yellow line on the road you will think the frt end is falling out of the car , especially on a curve. most states have installed rumble strips in the middle of the road to keep drivers awake. the first tme I did it in my a I thought I was loosing a wheel.

04-18-2015, 04:24 PM	#1
rob63mess Senior Member Join Date: Dec 2010 Location: newark ohio Posts: 569	another issue...strange wobble We were taking the roadster to dinner tonite and she was purring right along....I even commented to the wife how well it was running and how I was a mechanical genius and all. We turned a corner and began to accelerate, we must have been going about 20 mph and the car began to wobble violently....I thought I has a flat tire for sure. I pulled into a parking lot and all tires were ok....the wheels were tight. I checked everything out and headed for home. It ran fine.... tried everything I could to try to duplicate the problem but it ran and acted great no matter what I did....any ideas?

04-18-2015, 04:27 PM	#2
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 8,741	Re: another issue...strange wobble Do a search for Death Wobble. You need to check the whole front suspension for loose or worn parts. Bob

04-18-2015, 04:42 PM	#3
Walt Dupont--Me. Senior Member Join Date: May 2010 Location: Gardiner Me. Posts: 4,200	Re: another issue...strange wobble Tighten the tie rod and the drag like ends, when I first built 31 A, all new stuff, when I too corner on to another street, it went into that death wobble, I screwed the ends in until they bottoms and backed them out about one turn, I put many miles on in the last 19yr's and never had a wobble since. Also make sure you have enough caster. Walt

04-18-2015, 05:02 PM	#4
Goldhardt Senior Member Join Date: May 2014 Location: Commercial Point, Ohio Posts: 239	Re: another issue...strange wobble Have someone turn the wheel back and forth with you underneath. You may find stuff moving that shouldn't be. That may at least get you started in the right direction. My buddy had the same thing happen to him. The shaft that the pitman arm attaches to was not secured where it passed through the frame. The nuts were only finger tight! His was a very minor fix. You may get lucky as well!

04-18-2015, 05:11 PM	#5
HoarseWhisperer Senior Member Join Date: May 2010 Location: Ontario, Canada Posts: 1,470	Re: another issue...strange wobble Any chance you have a worn after-market rubber ball modification on the radius ball? __________________ I know a lot of things; I just can't remember them all. 1928 CCPU 82-A 1931 Roadster 40-B Dlx (Canadian)

04-18-2015, 05:17 PM	#6
Patrick L. Senior Member Join Date: May 2010 Location: Largo Florida Posts: 7,225	Re: another issue...strange wobble Sponsored Links (Register now to hide all advertisements) Something in the front end is loose. Start at one end work your way completely through it, from wheel bearing adjustment all the way back through to the steering box adjustment and everything in between including radius rod.

04-18-2015, 06:47 PM	#7
RUNNERBUN Senior Member Join Date: Nov 2011 Location: Queensland Australia Posts: 640	Re: another issue...strange wobble The death wobble can be caused by any of the following: Loose and worn ball joints Pitman arm loose on he sector shaft Loose wheel bearings Worn king pin and bushes (also check the cotter pin that fixes the king pin to the axle) Castor (worn radius ball will effect your castor) toe-in wear in the steering worm and sector gears or a combination of any of the above. I have not experienced it in the A, but did have the problem in my Model T. It always happened at low speed at around 20 mph. Applying the breaks made it worse. If I felt it coming on I gave steering a quick hard pull to the right and left and the wobble would stop. Not suggesting this procedure as a permanent fix. For your and everyone elses safety you need to fix the cause. __________________ Adjust your points with gentle blows of a 2 pound hammer

04-18-2015, 08:59 PM	#8
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: another issue...strange wobble The MOST COMMON cause for SHIMMY, is too much slack in the STEERING GEARBOX! Bill W. __________________ "THE ASSISTANT GURU OF STUFF"

04-19-2015, 09:34 AM	#9
Terry, NJ Senior Member Join Date: May 2010 Location: Bucks Co, Pa Posts: 3,740	Re: another issue...strange wobble It's best to go over the front end completely when the "Death Wobble" strikes. Jack up the driver's side and check the pitman arm and drag link ball for out of roundness. How loose are the wheels?loose Wheel bearings have been known to cause it too. How much slop is there in the king pin? Is there too much play in the steering wheel?Another giveaway is can you shake one wheel and have the other not move? The next thing is a little hard to find but It was a cause in my coupe. The spring shackle bushings! Mine were shot (both sides) and the whole front axle assy was shaking around. The is can be hard to find because when the car is at rest, the springs will feel solid, Note if the"eye' of the spring is touching the front axle. as Bill said, the steering box may need adjustment. There are four adjustments BUT they must be done in sequence and I don't recall what that sequence is. Terry

04-19-2015, 10:21 AM	#10
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: another issue...strange wobble OLDER Datsun & Toyota pickups were common or this, when they had a little too much worm & sector clearance, easily corrected by adjusting the screw & locknut! With steering in the straight ahead position, I'd just screw it down, SLIGHTLY firm with a screwdriver & back it OFF 1/8 turn. Regular old shimmy, the kind you have to stop, to get it under control, is usually caused by UNUSUAL undulations in road surface. Vermin's shimmy always happened in front of Bill Jones' house, it was caused by a loose rear drag link! He had ALL new parts, by the previous owner, BUT, the re-pro spring was TOO SHORT! The loading of the parts in the rear drag link end, Is also DIFERENT FROM ALL THE OTHER ENDS!! Some parts catalogs show this difference. Bill W. Bill W. __________________ "THE ASSISTANT GURU OF STUFF"

04-19-2015, 03:28 PM	#11
t farr Member Join Date: Jun 2010 Location: Auckland New Zealand Posts: 32	Re: another issue...strange wobble I had very bad death wobble and getting worse. We fixed all the mechanical problems and some that didn't matter. Seems I was trying to get the last bit of rubber off my tyres before I replaced them. Finally did that and not a sign of the wobble since. Silly Boy.

04-19-2015, 04:09 PM	#12
rocket1 Senior Member Join Date: Mar 2014 Location: Midland Park,N.J. Posts: 1,108	Re: another issue...strange wobble you should have knocked on wood when you made the remark about how well the car was running

04-19-2015, 04:19 PM	#13
grumpyoldsman Senior Member Join Date: May 2010 Location: Erie Pa. Posts: 104	Re: another issue...strange wobble first thing never say its running .great because it wont for long. next time you go where you were run over the yellow line on the road you will think the frt end is falling out of the car , especially on a curve. most states have installed rumble strips in the middle of the road to keep drivers awake. the first tme I did it in my a I thought I was loosing a wheel.