Gizmo52

Hey everyone. This one has had me biting my nails lately. I recently did my upper and lower ball joints, inner and outters tie rods, upper control arm bushings, center link and idler arm. And now the truck has bumpsteer and tends to wander all over the place. The only two things I could think it would be is the steering shaft or the steering box. I haven't got my sway bar on yet becoud I have to fab up the sway links But that shouldn't change the bump steer and I know the alignment is spot on.

What do you think it could be? Maybe add a steering stabilizer? I'm running 305-65-17 at 60 psi aslo. If its the steering shaft I was going to modify mine with a second gen shaft. I also tightened up the adjustment on the top of the steering box that tightens up the play. Its not to the point of binding or locking up but could it be too tight still? The steering wheel also has some play in it.

​​​Thanks again for the help guys!​​​​

NJTman

I was told by a world class power steering guru that...

The preload adjustment on the box should never be messed with, unless the box is on a test bench, set by factory service manual standards

I'm not a guru, so, take that statement however you wish.

How do you know the steering geometry is spot on ? Was the truck aligned on a state of the art alignment machine, or a piece of string from tire to tire.? My 4x4 toe adjustment was a mere couple degrees off, and it was all over the,place

I find that when I don't go about doing something in a methodical series of steps, and I try to do everything all at once, it is difficult to,pinpoint what I did wrong in the process

gyman98

Well if it didn't do it before you did all the work and now it does, it's something you did. My guess would be alignment is off. Or maybe something isn't fitting quite right or something didn't get tightened?

Gizmo52

All is tight. The alignment was done on an alignment rack not by string but I will get it checked again just to be sure. The steering shaft does have some play and I can try to loosen the box adjustment a little. But all I can think it would be is that if the alignment is good than maybe the problem was there before just not as noticeable because the steering was worn out? And no it did not do it before.

patdaly

What year truck are we talking about?

NJTman

Caster
Camber
Toe
Wheel bearing play
tire pressures (too soft or too hard)
tire condition
Steering gear pre-load being adjusted incorrectly
Steering shaft play
worn springs
Worn shocks

Gizmo52

Its a 1990 d250 with the getrag. Bearings were ok Shocks ok all alignment specs ok I'll try to loosen the perload on the steering box and I know my steering shaft has some play tires are new and psi is at 60

NJTman

What does the tire rating say ? D rated or E rated?
Max psi imprinted on the side of the tire?

850 lb engine sitting over a 4500 lb axle should have E rated tires at 80 psi. At least that's what I would be doing

patdaly

My apologies, I keep forgetting there are 2WD versions of these things.

Alignment in spec. can mean quite a variance in how it drives, did they happen to actually give you a sheet where each thing is set?

I am with NJT, I don't run less than 65 PSI on E rated tires, I don't usually run them at the full 80, but even with the stiff sidewalls of my Coopers, they don't like less than 65.

NJTman

Each tire has its own sidewall stiffness and the reason I running at 80 psi is because over the years I found that the tires wear properly. If I run them anything less than 80 then what happens is is the outsides of both tires start to wear in the front. The actual tire pressure required is based upon the tire you buy the stiffness of the sidewall and your observations as to how they wear. My Toyota pickup is small and I can't run the tires at full pressure because the center of the tire wears out. The Dodge on the other hand it's so heavy that I can't run them anything less than 80 otherwise they wear out on the side walls edges. It's up to the OP to determine what is true tire pressure is required

My rear tires on the other hand I run anywhere between 70 and 75 PSI. During the winter when I put 500 pounds of weight behind the rear wheels pressure really should be run at 80 psi. As soon as it snows I drop it down to about 70 to get a little more grip

My experience with low pressure in tires or tires that are not designed for a vehicle such as D rated tend to be very squirmy on the road

Gizmo52

Well I put my sway bar on last night finally and it seemed to help a little. I like the way it road at 45 psi but I can feel the handling difference at 60 It just feels like I'm hitting a wall when o hit a pothole. But I'll bump it up to 80 and see how it feels. Also here is the pic of the alignment sheet

mknittle

Maybe not enough caster. I don't mess with 2wds much but that seems like there should be more.

u2slow

Agreed. Think you have a caster issue.

Make sure the upper control arm bushings are in good shape, and you adjust caster with the attaching bolts... they have a cam action. Dialing one out and the other in to max-out the caster in one direction. Vice-versa to max it out the other way. I forget which way is 'right' but but you'll find out in a hurry with a test drive.

Adjusting both cam bolts evenly affects the camber mostly.

Gizmo52

Just an update everyone. I have gotten my sway bar installed and it helps with the bump steer a lot but the truck is still wandering. Tire pressure is at 60 psi. And I have wheel spacers coming because my Tires now rub the sway bar. But I have not had time to get the alignment checked or adjusted. Any other thoughts? And I checked everything in the front end and its all tight.

u2slow

When stuff acts funny like you describe, I go back to basics.

Measure the toe as best you can with a tape measure. (compare measurements between front tires fore and aft.)

Use a level to find out how plumb your wheels are. If neither of those seem out of whack, you probably need more caster.

Also, what offset wheels do you have? Do they have more or less offset than stock? If adding the spacers fixes the wandering, that may be the issue.