Steering box slop / steering shimmy?

Northwood

Northwood

Lost in Iowa
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Sep 29, 2016
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Davenport, IA
With the drag link removed from the pitman arm, how much rotational slop is expected when turning the pitman arm? (Or vice versa, turning the steering shaft)

I can wiggle my pitman arm back and forth about 1/16th of an inch with no resistance before it starts to turn the steering shaft. Is this possibly the cause of my steering shimmy that's turned to death wobble twice over the last year?

For the record the steering was apart to replace the tie rod/drag link end at the pitman arm. I could feel, but not see slop, in what I thought was the joint during a dry steering test. Turns out it was in the steering box.

@Jerry Bransford @mrblaine
 
Northwood said:
I have not. Assuming you mean the allen head on top of the steering box? Was going to try that until the FSM made it sound like my steering box would implode.
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I'm curious on this topic too...am I correct to say you loosen the 5/8" bolt then take a 3/16" allen wrench in there and move it a quarter turn clockwise at a time, tighten the bolt up, then drive and see if it needs more adjustment?
 
EJD said:
I'm curious on this topic too...am I correct to say you loosen the 5/8" bolt then take a 3/16" allen wrench in there and move it a quarter turn clockwise at a time, tighten the bolt up, then drive and see if it needs more adjustment?
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Exactly correct,I had about an 11 to 1 slop in steering wheel movement.
I adjusted a little less than 2 rounds.
Make sure your steering does not bind and still wants to return to center after making a turn.
My death wobble is now gone.
 
Imapepper said:
Have you tightened the gear lash in steering box? Should be no slop
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Common myth, but oft repeated. Here is a way to help you understand why that is bad. The steering gear is just that, a gear and the lash is set just like the back lash on your axle gears. Helping yourself to a set of unknown tolerances by monkeying with something just for the sake of monkeying with it is not prudent.

This video shows some stuff to help you get an understanding of what is going on, why the lash matters, and why the on center lash adjustment won't fix the problem if the bore is worn.

For grins, search You Tube for steering gear lash adjustment and you'll find a plethora of assholes telling folks how to do it wrong. They don't understand either.
 
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mrblaine said:
Common myth, but oft repeated. Here is a way to help you understand why that is bad. The steering gear is just that, a gear and the lash is set just like the back lash on your axle gears. Helping yourself to a set of unknown tolerances by monkeying with something just for the sake of monkeying with it is not prudent.

This video shows some stuff to help you get an understanding of what is going on, why the lash matters, and why the on center lash adjustment won't fix the problem if the bore is worn.

For grins, search You Tube for steering gear lash adjustment and you'll find a plethora of assholes telling folks how to do it wrong. They don't understand either.
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So, when does that play become too much? And is the only solution a new steering box if 1/16th" movement at the end of the pitman arm is indeed too much? Good thing there aren't any reputable remanufactured boxes I've been able to locate, if that is my only solution.
 
Northwood said:
So, when does that play become too much? And is the only solution a new steering box if 1/16th" movement at the end of the pitman arm is indeed too much? Good thing there aren't any reputable remanufactured boxes I've been able to locate, if that is my only solution.
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1/16" of movement divided by the length of the pitman puts the lash at 11 thousandths at the sector gear. It would be unlikely to get much less than that. I'm okay with about 1/2 turn on the adjustment nut and screw. No more than that though and if you lose return to center, you have it too tight and it won't take long before the slop is back.
 
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mrblaine said:
1/16" of movement divided by the length of the pitman puts the lash at 11 thousandths at the sector gear. It would be unlikely to get much less than that. I'm okay with about 1/2 turn on the adjustment nut and screw. No more than that though and if you lose return to center, you have it too tight and it won't take long before the slop is back.
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Would it be safe to say that isn't my issue then, or is it worth trying the adjustment? I'm at a loss if this isn't my issue, because nothing else in the front end shows any movement. Everything but unit bearings is new within the last year and those are tight and quiet as could be...
 
mrblaine said:
1/16" of movement divided by the length of the pitman puts the lash at 11 thousandths at the sector gear. It would be unlikely to get much less than that. I'm okay with about 1/2 turn on the adjustment nut and screw. No more than that though and if you lose return to center, you have it too tight and it won't take long before the slop is back.
Click to expand...
So after 20 yrs of service my steering box should have only needed 1/2 round of adjustment? I'm sure a new box would work too, but why?
 
Northwood said:
Would it be safe to say that isn't my issue then, or is it worth trying the adjustment? I'm at a loss if this isn't my issue, because nothing else in the front end shows any movement. Everything but unit bearings is new within the last year and those are tight and quiet as could be...
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I looked back and don't see what the issue is exactly?
 
Northwood said:
Steering shimmy when hitting certain bumps. Has turned into full on death wobble twice.
Click to expand...

So it sounds like you're describing bump steer.

Two things:

1) Do you have a stock pitman arm or a dropped pitman arm?
2) When was the last time you aligned your TJ and set the toe-in?
 
Northwood said:
Steering shimmy when hitting certain bumps. Has turned into full on death wobble twice.
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Stock pitman arm, unless previous owner changed it, but it looks stock to me. Track bar and drag link are parallel. And I set the toe to between 1/8" and 1/16" in a couple months ago
 
If in doubt, take a photo of the pitman arm so we can tell if it's stock or not. I only say this because aftermarket pitman arms are known to cause bump steer, which is what you are describing.

I suppose it could be that you need a new steering gear box in general, but I actually don't know what the symptoms of a bad or failing steering gear box are.
 
Drizit said:
Usually they leak like crazy long before they fail.

—
There must have been a time
when we could have said no.
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Good to know! I dread the day it happens to mine. That Mercedes gearbox isn’t cheap!
 
Chris said:
Good to know! I dread the day it happens to mine. That Mercedes gearbox isn’t cheap!
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You can now get rebuild kits for em so you don't need to fork out all the money.

I modified my frame to accept to older style boxes, it's not acctualy that big a deal to do if you have a welder, and access to an older model part out.

—
There must have been a time
when we could have said no.
 
Chris said:
If in doubt, take a photo of the pitman arm so we can tell if it's stock or not. I only say this because aftermarket pitman arms are known to cause bump steer, which is what you are describing.

I suppose it could be that you need a new steering gear box in general, but I actually don't know what the symptoms of a bad or failing steering gear box are.
Click to expand...
20180312_065250.jpg

There she is, in all her glory
 
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