1973 f-250 Explorer Camper Special 2wd.
The problem is huge oversteering. That being said, I believe the original problem was with the rag joint.
Now that i have replaced the radius arm bushings, complete tie rod assembly, drag link, rag joint, power steering gear box, and had an alignment done, it wants to steer itself.
When I turn the wheel in either direction it wants to go all the way by itself.
Thought it might be the rebuilt gear box I got but have put on another one and it does the same thing..
It has no wobble and steers straight till I turn the wheel, then I have to hold it back to keep it from turning all the way.
Anyone ever have this problem. Could I have installed something wrong?

 

Not an expert, but I believe I read another user's thread just a few days ago that had the exact same issue. I'll see if I can find it.

 

Any help is appreciated

 

Frozen kingpins is the first thing I would check.
Disconnect the tie rods at the wheels, front wheels off the ground and try turning each wheel left & right. If they are hard to turn the kingpins are frozen and need to be replaced.
My 81 F100 with kingpins were frozen and on the test drive almost ended up in a ditch as the wheel did not return back to center. It also had some bad bushings but the frozen kingpins was a biggie.

When the alignment was done did they give you a print out of the before & after specs? Caster being off could also be a cause as that helps return the wheels back to straight.
Dave ----

 

Thanks for the info.
Forgot to mention the alignment guys said I need Kingpins before alignment could be done.
I got them replaced and alignment was done. Only some "Toe" need to be adjusted.
Could a bad steering column be a cause? It's the only thing I can think of at this time.
Not to many places will work on the older stuff. Anyone know of someone in WNC that is good for these trucks?

 

Resurrecting this post, curious if the OP ever found resolution?

I have a '73 F250 2WD Camper Special. I recently rebuilt the motor, rebuilt the entire front end, just had it aligned and it is down right dangerous at freeway speeds. I can be best describe as unstable, as if the truck is being blown all over the road. Unfortunately, I've done so much work, it's tough to put my finger on any one item.
Items done
New king pins and bushings
New tie rods
New springs
New shocks
New red head gear box
New rag joint and new bearings on the steering column
New radius arm bushings

I've raised the truck and wiggled the tires and there is absolutely no play. The rods are snug. Couple nights ago I rechecked my wheel bearing nuts and radius arm nuts. The truck seemed to drive ok with my old tires (33" on 16.5" rims). I just paid a pretty penny for new tires and rims (265/75/16) with an alignment and truck drives absolutely horrible above 45 and down right scary to keep control of at 60 mph....like death wobbles.

I've owned this truck for about ten years was sitting in the garage for about the last three waiting for me to put together. I used to own a '79 F100 and rebuilt the front end on it, years ago. One slight difference I've noticed is there is a "hard" sway bar that bolts between the radius arms. I recall having to use a bit of force to get it to fit and I'm wondering if I should pull it out or at least fiddle with moving it a bit in the slots?? My other thought is to take it in ask the place that performed the alignment to check it again (or bring somewhere else). I'm not sure if the new tires are simply amplifying the condition?

Toe is 0.09* on the left and 0.07* on the right for a total toe of 0.16*. I'm not entirely certain how that translates to the 1/8-1/16" I'm wondering if more toe in would help? Obviously, I changed a lot of variables, thoughts on first place to start? I haven't been able to find anything mechanically obvious that would make it so difficult to track straight down the road.

Thanks in advance for your time and helpful thoughts.

 

I had one to do this to me once, Before I could figure it out it just about Killed me. Running along @ 45 MPH and instantly done a 360 in the Middle of a 4 Lane. It was a Dragging Caliper that finally Locked up. I had to Cough for 2 days to get all the Vinyl out of my A$$.

 

Well, I don't know about the OP (very curious what happened as well!) but you ruled out my only suggestion when you said new tires.
The only time I've ever experienced this same thing as the OP's (but nowhere near as bad as yours) was when I bought two new tires and put them on the rear of my Bronco and kept the two best old ones for the front. Yikes! Over-steer city.

I drove it to work one day only, and the next day bought two more new tires to match. No more problem.

Going to have to think about yours. Thanks for the thorough description. Should help...

Paul

 

Has anyone ever put together a chart to equate the new "degree" toe settings to the old "inch" toe settings (with different tire sizes)?
I know we've figured it out individually a few times over on classicbroncos with the guys that remembered their high-school geometry, but I'm not up on those skills.

Be nice if we had a PDF or Word doc we could reference when needed.

Paul

 

1Ton might be own to something if the front Tires were wore in with the worn Parts..........

 

The Scrub would be Different own the Tires compared to what they were broke in with.

 

What about air pressures in all this thinking?
Check yours to see that they're not necessarily pumped up to the max.

Paul

 

.16 is less than 1/16 of an inch over 1/8" (.125"). 3/16 would be .1875". I would not think a little over 1/32nd over spec should effect the steering with the symptoms you're having. What were the castor and camber #s when the alignment was set? Could also be to much preload on the new kingpins.
Mark.

 

Does it actually want to keep steering or does it just not want to return to center ?

If everything is in good condition my first thought is caster.

 

Thanks for the responses guys. Yeah, I sat down last night after posting and did some trig to understand how he degree measurements agreed with the inch spec. It's somewhat easy if one has a calculator with trig functions.

So, here were some rough toe in numbers...I'm assuming the toe measurement in inches is from roughly edge of tire to edge of tire, inner wall, front. From my understanding the 265/75's are around 31". If I roughly overestimate to 32", that puts my radius at 16", TAN theta (the angle) = toe/radius, doing some math, toe = radius*TAN theta, and assuming an angle of 0.1 degrees, 16" * TAN (0.1) = 0.028. A 1/32 runs in at 0.031, so I'm close to two times that number to be at 1/16" total- all rough numbers, but in the ball park. So, I'm thinking it could use more toe in, but it isn't terribly out. I was told the new rims have no offset whereas I believe the old stock 16.5's had some, just not sure how much, which way, and the overall impact going to 0.0 offset.

So here goes with the rest, my guess is that it won't post laid the way I intend:

LEFT , RIGHT

CAMBER 0.5* , 1.1*
CASTER 1.2* , 2.4*

It is odd how the passenger side is almost twice as much as the driver side, but going by the shop's color coding of "in" versus "out" of tolerance, looks like these values are OK?

Back in the day when I had my '79, I do recall bringing the truck to an RV shop to have the I-beams bent into alignment. Granted, I was trying get my old truck to steer near perfect (I realize a near impossibility with these old trucks- they drive like old trucks). At this point, I'd just be comfortable going 55 MPG without wagging all over the lane.

I'll definitely check the tire air pressure.

It's going to be a few weeks before I can work on the truck again, been busy swapping power trains for my father in law's hybrid civic- not fun at all.

Thanks again for the suggestions guys as I've put a lot of blood, sweat, tears, AND MONEY, into this old truck and to have it drive horrible is just all wrong ;(

Thanks to all the veterans out there, happy Memorial Day weekend!