My dad's truck has a problem that is frustrating him to no end and hopefully someone here can help. The truckis a stock 1949 F-1 drives fine until you hit a bump or a pothole just right and then it will rip the steering wheel out of your hands and flop left to right violently until it comes to a stop. Then you can go on as if nothing happened and not knowing which bump or rut will set it off again. He is baffled because he has replaced the king pins, bushings, wheel bearings,shocks, springs, and shackles all with new parts and nothing changed. I forgot to ask about the alignment, but he is not the kind of person to overlook that. I do know the steering box has not been rebuilt, yet. I know he has tried adjusting it with no change in the problem.

I drove the truck once last year and I experienced the problem first hand, not fun. This truck is no show truck, but a great driver until this started happening. My father is very capable when it comes to cars, esp. old Fords, having completely restored a few frame off and driving them extensively, but this thing has him stumped. Has this happened to anyone else and what solved it?

I did do a sarch but could find nothing similar to this problem, tried "bump steer" and "shimmy" any other terms I should have been searching for?

Thanks

 

Could he have overlooked the bolts fastening the steering box to the frame? I had the exact problem and found out the three bolts were loose. I replaced them and tightened them down and never had the problem again. I know it sounds stupid but sometimes the simplest problems are over looked.

 

I had the same promlem as bobj49f2.The truck would wander all over the place. I found out one bolt was missing and the other two were loose. Replaced missng bolt and tightened the others. Drove fine after that.

Terry

 

Improper tow in will set up a shimmy. Check your tow in.

 

Toe-in is fine. We replaced the three bolts holding the steering box in, the old ones seemed fine, they were tight, but worth a shot. Unfortunately the truck will be undrivable for a bit longer since we found the radiator was leaking from the top tank, so we pulled that today. I will be back in Seattle by the time he gets it fixed, so no test drive for me. When he gets it back on the road I will report back. So if this doesn''t help, any other suggestions? Steering box itself?

 

check your lugnuts. Also, you can grab the pitman arm and steering shaft above the box and give it a wiggle. Any play would likely compound a problem on the road.

 

https://www.ford-trucks.com/forums/4...runking+monkey

 

My 48 f-1 stock
wandered when I hit bumps in the road
tow in was the big problem
also check your drag link springs and cups
I also put new skinny type tires on the front that made steering easier
Joe

 

We grabbed, pulled and checked everything today, nothing obvious. When this thing was on the road it drove fine, like any other F-1 on bias plies, it was just hitting some random pothole (and not always) that would send it into this violent shake. It really stinks to now have to fix the radiator just to see if what we did today helped at all.

 

You mentioned the toe-in being fine. Check it again, if it is within specs, add a little bit more toe-in. You can go quite a bit on these trucks (up to 1/4")

My truck ran and drove great but my tie rod was bent. I straightened it out and then teh truck had a terrible case of the dreaded Drunken Monkey. I reset the toe and haven't had a lick of problems ever since

Bobby

 

Most of the time shimmy is caused by bad alignment (toe-in off) or worn steering parts (tie rod ends, steering box, drag link parts, king pins, etc.) However, these old trucks also had very little caster built into the axle. If you can find no other worn parts, I'd invest in some axle shims and increase caster a little. That might help. As a last resort, you could try an aftermarket steering dampner. I had a 32 Ford with a straight axle years ago with the same problem and while the steering dampner was not a cure all it did help some.

 

TATE, might seem minor but, if tires are directional, could they be on wrong side? dry rot? air pressure? if not, recheck shims on kingpins.

 

I think we will check the toe-in again, you all have convinced me. The tires are bias ply white walls, fairly new. Thre truck does sit a bit higher in the back, but I thought that was pretty normal. I leave here today, a bit disappointed that I won't be around when it is back on the road. Thanks to you all for the help and suggestions.

 

Quick update for those that care. The truck is still not back on the road unfortunately. The leaking radiator is fixed and filled with Sierra anti-freeze, so far it is the only kind available new he has found that doesn't foam in the flatheads. So now the brakes are in need of rebuiding, so that is the next task for the old man before he can get it on the road again. Unfortunately I am now back in Seattle, a bit too far to lend a helping hand.

Thanks again for the help, I hope I can update soon and tell you that the wobble is gone.

 

Glad to hear you made some forward progress.

Good luck
Bobby