New poster frequent lurker. I have a 51 f1 and thanks to many of your posts I have been able to resolve a few issues with the truck. I have new one I believe with the suspension or steering. This truck was stored in my wife's Grandma's shed on the farm in the Midwest. We have owned the truck for ten years or so and we finally had it shipped to us in Central Oregon last Summer. I have a shop manual and have been doing a lot of research on the truck. I have found it to be quite interesting. Anyway, the truck is getting driven more now than it ever has and I just want to make sure it is safe. The other day my daughter and I went for a drive and once the tires got warmed up I didn't notice too much thump, thump on the pavement. Then out of the blue we were just about home and as we reached a speed of about 45mph the thing started shuddering like crazy. I slowed and came to a stop and half expected to see one of the wheels coming off the axle. Nothing noticeably wrong with the truck so we got back in an made it home. There is some play in the steering wheel and I assume the box is shot. Would the steering box being worn out cause this type of shuddering? I did tighten the front left motor mount bolt as I noticed it was loose prior to the drive. Could that have be the culprit? As you can tell I am not a mechanic and pretty green when it comes to the makeup of these machines. I am learning as I go. Any help would be greatly appreciated.

 

Sounds like a front end shimmy....usually caused by worn out parts. Tie rod ends, drag link, king pins, steering box, even spring bushings can contribute. Most likely a combination of several. Tell us more about your truck and what you have done to it so far. Post pictures if you have them. Oh, and welcome!

 

I agree with Tinman52, I had the same problem and ended up replacing ,or rebuilding all items mentioned, and beleive me they all were past due. in the end it turned out to be caused by an out of balance (brand new) brake drum. somtimes ya just have to take it step by step, and ask questions. i enjoyed every step of the way. good luck (jimmy)

 

How old are the tires? Are they biias ply or radial? Before you check out the steering, see if they are just old hard tires, which it sounds like from your description of flat-spotting. But it can't hurt to check out the whole suspension and steering system as well as the brakes.

 

O.k. here goes. New brakes, master cylinder, wheel bearings, wiring harness for 6 volt, passenger side door lock mechanism, driver side latch work to eliminate handle sag, exhaust, radiator, and hoses (should have done water pumps when I had it apart but didn't). New shocks have new mirrors but can't for the life of me get the old pins out of door hinges will need some help with them any ideas would be great. Luckily I have a bunch of cardboard cause it leaks oil like any old truck. I have and oil pan gasket with real seals to install but I am a little nervous I don't want to screw it up and end up spending more to have something else done. I haven't found a gasket yet in reproduction for the "clean out" in the bottom of the pan. The six inch in diameter cover in witch the drain plug screw into. Thanks for you replies I am starting to gain a little confidence with this thing. Oh the tires are old in years but not old in service. Grandpa, who owned the truck prior to me, put some six ply bias tires on which explains the thump thump after it has been sitting for awhile.

 

The dreaded "death wobble" and you lived to tell about it!

Actually its pretty common and as the guys said, everything connected to the front end is worn. Maybe just a little bit, but put all those little bits together and its enuf to cause the shakes. Welcome.

Scott (tinman52), it was great to finally meet you the other day. That's the best part of this hobby/obsession!

 

Also, check the "toe in" on the alignment - only thing not mentioned so far.

 

old ford steering boxes can be adjusted . theres a set screw in the box with a jam nut on it . loosen the jam nut and tighten the screw till the steering begins to bind up , then back off and tighten it down . the rest of it is as they have said just worn out parts , or maybe the truck has old radials with slipped belts ????

 

Go look at your wheels and see if you can tell if one of them lost a wheel weight that was placed there when they were balanced. It could have very easily flown off the wheel which would have instantly made it start shuddering like that. Ten bucks says that's your problem. Look for a clean place where a weight used to be.

 

55 f350 Is the jam nut on the exhaust manifold side of the box? All I see is is what looks like the head of a bolt in the middle of a square shaped cover. Do I remove that to gain access to the set screw?

 

It's not a bolt, it's actually a nut with a slotted set screw in the center. Make sure your wheels are straight. Hold the set screw while backing off the nut....then turn in the set screw till it starts to tighten. Don't over tighten or the steering will bind. Hold the set screw and re-tighten the lock nut. You may have to fiddle with it till you get the right feel.

 

The setscrew on the box sets the end play of the sector shaft. It won't cure slop between the worm and sector, or bad bearings on the worm. If you over tighten it will destroy the sector bearing pretty quick.

 

It sounds like a tire issue to me. They might not have too many miles on them but if th epoor old bias plies were sitting for a long time they could have developed a "set" or some flat spots. Like you noticed it might get a bit better after they warm up and become more pliable but they might still have flat spots. As you drive around and make corners the flat spots won't be in sync anymore and it may feel smoother, occasionally two or more of the flat spots may get in sync with one anther and try to bounce you out of the cab.

If it is the "death wobble" I'd check all the front end components for excessive wear and check the toe-in settings. The "death wobble" is when your driving approx 35-45 MPH and you hit a small bump and the front end starts to shimmy real bad...like the tires are bouncing back and forth and up and down and nothing you can do makes it better....sometimes you have to come to a complete stop to make it quit.

So, all that being said, when the truck does its shudder thing, can you mainly feel it in the steering wheel or in the seat of your pants?

OH, I almost forgot....welcome to the board
Bobby

 

Bobby,

I feel it in the seat of my pants. Scared the life out of my daughter. We did come to a complete stop and it seemed to go away for the time being. Thanks for the welcome.

 

Since you can feel it more in the seat of your pants than you can in the steering wheel I would say you're not fighting the "death wobble" and are probably just suffering from old bias ply tires.

I recently got rid of some 30 year old bias plies on my truck in favor of some radials. WOW! what a difference. I can now drive where I want to and not where the truck wants to.....lol

Look the tires over, one of them might have developed a bubble or something.

Bobby