Play/Slack in Steering

My advice is to take it to a Freight liner shop and let them fix the problem. I agree that if you over tighten the screw on the side of the gear box, it could lock up on you and you would be doing more damage then good. Wondering could be many things such as worn out tie rods, uneven distribution of the weight on your coach. Tire pressure not right. Too much weight on the rear to make the front end light. Best to let professionals take care of the problem.

Yes, setting caster AND toe-in toward the high side of spec helps.

The feeling of loose steering (ie dead zone between left and right) at highway speeds is a symptom of not having enough +caster.

OK, my response:

Absolutely start by checking for play in all the other components BEFORE looking at the steering box.

Takes two people. With engine OFF, have your helper in the driver's seat. Have them turn the steering wheel through arcs left/right/left... Start with small arcs and increase until the right wheel just starts to turn. Look for any play from the right steering knuckle through tie rod ends, left knuckle, drag link, etc.

Next, while you are looking at the top of the steering box/bottom of the steering shaft, have your helper make very tiny arcs. There should be zero play in the steering shaft/U joints.


Once you have verified no play in the "rest of the steering components" it is time to look at the steering box itself. First question is what steering box to do you have. Some are adjustable, some like Sheppard boxes are NOT. To remove play from a Sheppard box, the box must be removed and blue-printed. There is a company in Washington state that specializes in this. If you have a Sheppard box, I can look for information on that company. Steering box adjustment is NOT something to be done lightly/incorrectly. Easy to do permanent damage if over tightened.

ScottG wrote:

Ductape wrote:
It would be a mistake to begin with adjustments to the gearbox before even checking front end and steering parts for wear.

I don't want this to sound wrong, but if you need a picture it's best to pay a good chassis shop to do this work.

Has the alignment been checked? That can cause wandering as well.

Add on devices won't fix this, just mask it.

Very true. no adjustment will cure suspension play or allignment issues.
Also, adjusting the box on the vehicle by tightening the screw down is very wrong and can lead to major destruction of the gear. If you do try this route then turn the wheels to one side and then make the adjustment. By design, the box has more play in the center than at lock. So if you tighten it too much at center it will bind at sharper turns and tear it up.

That's just backwards. By design the gear box is tighter in the center.

Richard

Ductape wrote:
It would be a mistake to begin with adjustments to the gearbox before even checking front end and steering parts for wear.

I don't want this to sound wrong, but if you need a picture it's best to pay a good chassis shop to do this work.

Has the alignment been checked? That can cause wandering as well.

Add on devices won't fix this, just mask it.

Very true. no adjustment will cure suspension play or allignment issues.
Also, adjusting the box on the vehicle by tightening the screw down is very wrong and can lead to major destruction of the gear. If you do try this route then turn the wheels to one side and then make the adjustment. By design, the box has more play in the center than at lock. So if you tighten it too much at center it will bind at sharper turns and tear it up.

It would be a mistake to begin with adjustments to the gearbox before even checking front end and steering parts for wear.

I don't want this to sound wrong, but if you need a picture it's best to pay a good chassis shop to do this work.

Has the alignment been checked? That can cause wandering as well.

Add on devices won't fix this, just mask it.

On our 1996 Freightliner the steering box has a screw with a locknut on the right side of the box (right side determined while sitting in drivers seat looking forward). It protrudes through the frame so you have to look on the inside of the frame to find it. Tighten (clockwise) very slightly 1/8 to 1/4 turn and test drive. Do not over tighten!
Good luck!

You really need to look at the stearing box. If it is adjustable there will be a screw locked in place by a large nut. Loosten the nut, using a large flat blade screwdriver turn till it stops, maybe a quarter turn or less. While holding the screw in position, tighten the nut. Test drive, readjust is necessary. There does need to be a bit of play to work correctly.