Gearbox adjustment or shaft connection problem?

msplant

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Apr 6, 2019
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Ashtabula Ohio
I just picked up my first TJ and there is a lot of play in the steering even before the gearbox is engaged, that is the play I want to fix. Admittedly I will be doing other front end fixes in the near future but I don’t think any of that would cause the play I’m experiencing.

I took it to a mechanic who just changed the steering gearbox, he said it was leaking but the play is still present.

So now there is a brand new gearbox and I have examined where the play is by following the shaft all the way to the top of the gearbox, it’s moving right at the connection but takes a few inches of steering movement to actually start to move petmin arm.

The mechanic is saying it’s everything after the petmin arm, U joints, tires, ball joints, etc. but my research on here makes me think he is looking in all the wrong places.

I just had my wife move the steering wheel with the Jeep off, and she was able to rotate the steering probably 3-4” to each side from center before it was “hard” - since the power steering is off she was right in the play area before the wheels engage.

The shaft has immediate response to the wheel turning, all the way along the shaft but right below where the bolt that holds it onto the steering box I can see it doesn’t move the ring above the box or the petmin arm, I’m assuming this play is in the box itself.

I’ll admit I am new to TJ and also new to mechanics but I’m a fairly logical guy and to me it doesn’t even seem to be the shaft, it looks like it’s the gears which I just replaced!! Now I’m going to try to adjust the gear box today but my concern is that my steering doesn’t return to center already, but I’m assuming this could be bad u-joints, ball joints, control arms causeing that but I don’t know.

Can you guys help me understand if it’s feasible that the lower shaft may not be engaging and therefore needs replaced? I’m wondering if the connection to the gearbox may be able to cause play? Can the lower shaft connection at the bottom be stripped or something?

It does appear someone put spacers on the springs, I’m guessing 1.25” based on my measurements and I’m running 31’s - I don’t really know much if anything else was done to accommodate for the lift, I just picked this Jeep up and don’t know much about it.

I have looked at a ton of articles on here and I expected the gear box to fix it. Any chance or way to test if it’s a bad replacement gearbox?? Need some help here!
 
First, regardless of how many folks tell you that the box can be adjusted, the reality is that should not be done except in very rare circumstances. If you have poor return to center that you didn't have before the box swap, chances are high that the box is worn.

The way you check to see if the box is the culprit, turn the steering wheel and see if the steering shaft rotates before the pitman arm moves. If it does, there is excessive play in the box.

Now, here is where the truth about why you should not generally adjust the box comes into play. Inside the steering gear is a piston (why the end of the box looks round). The piston moves front to back and has part of a gear on it. That gear engages a section of gear on top of the sector shaft that the pitman attaches to. If the bore is worn and they wear where they sit most of the time, it will show up when it moves front or back out of that worn area into the less worn parts and you lose return to center. The bore wears because the sector shaft sits beside the piston and continually pushes the piston over to the side of the bore it rides in. When you adjust it, the little screw moves the sector shaft up and down to tighten the lash between the two gear faces. Up is tighter, down is looser. You may get it tight on center and then it will be far too tight as the piston moves into the less worn areas of the bore.

If perchance your mechanic swapped in an A1 Cardone box, there is a high likelihood that it wasn't even rebuilt, just cleaned and painted.
 
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Thanks Mr Blaine!

I did watch the video on another thread and I get how the box works now, I appreciate the detail explanation you provided. The jeep did not return to center before I had him change the gearbox - not sure if that makes a difference.

I will admit it is bit smoother than before but the play is still present. I suppose I may need to take the box off again if it's bad so at that point I can move it to see if there is play in the box itself. I will check to see what he changed in, I assume it was Cardone as it was roughly $150.

With a minor lift and larger tires is there a preferred box I should use? I have seen them upwards of $1000!
 
Thanks Mr Blaine!

I did watch the video on another thread and I get how the box works now, I appreciate the detail explanation you provided. The jeep did not return to center before I had him change the gearbox - not sure if that makes a difference.

I will admit it is bit smoother than before but the play is still present. I suppose I may need to take the box off again if it's bad so at that point I can move it to see if there is play in the box itself. I will check to see what he changed in, I assume it was Cardone as it was roughly $150.

With a minor lift and larger tires is there a preferred box I should use? I have seen them upwards of $1000!
I have not found a good answer for what steering gear to use. The issue is there are no more new ones. All the standard bore TJ boxes are used and that is what is in the core bank. I won't install a reman box unless the owner is willing to pay me to R&R it if he doesn't like it since no one else will pay me to swap it either and I have no way to verify that they are good or bad before I swap it in and it gets driven. I will swap a new one in and out for free since I trust that a new one won't require that very often so I'm glad to be responsible for the success of the swap.
 
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Don’t rule out the shaft u joints above the gear either.
 
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Thanks Andy, I totally agree but most of the play right now is after the u joints in the shaft so it is hard to even see if the shaft will need replaced until I clean up the biggest slack. I'd love to get it perfectly tight but for now I think hitting the biggest play first makes sense. After that I will be able to get a better test on other components.

Can you just replace the u-joints in the shaft? I assumed I'd have to get a new shaft which would get me new bearings as well.
 
Not to my knowledge . I did a Borgersen , but a stock type unit seems tough for it's size .

Thanks Andy, I totally agree but most of the play right now is after the u joints in the shaft so it is hard to even see if the shaft will need replaced until I clean up the biggest slack. I'd love to get it perfectly tight but for now I think hitting the biggest play first makes sense. After that I will be able to get a better test on other components.

Can you just replace the u-joints in the shaft? I assumed I'd have to get a new shaft which would get me new bearings as well.
Not to my knowledge , the stock type replacements are available I think, and the Borgersen shaft is nice.

I hate excessive play in steering.
 
Update, I actually tightened the gear box adjustment screw and I am getting a much faster response to the pitman arm.

Still have a little and still not returning to center but I am reading a lot of varying info around that one. May need alignment, I just checked it roughly and it seems to be toe in about 1/4". Next I will be circling back to seeing about play in the shaft U joints and also after the pitman arm.
 
I had a loose pitman arm after a lift job , plus some other weird stuff.

Hang in there.
 
First, regardless of how many folks tell you that the box can be adjusted, the reality is that should not be done except in very rare circumstances. If you have poor return to center that you didn't have before the box swap, chances are high that the box is worn.

The way you check to see if the box is the culprit, turn the steering wheel and see if the steering shaft rotates before the pitman arm moves. If it does, there is excessive play in the box.

Now, here is where the truth about why you should not generally adjust the box comes into play. Inside the steering gear is a piston (why the end of the box looks round). The piston moves front to back and has part of a gear on it. That gear engages a section of gear on top of the sector shaft that the pitman attaches to. If the bore is worn and they wear where they sit most of the time, it will show up when it moves front or back out of that worn area into the less worn parts and you lose return to center. The bore wears because the sector shaft sits beside the piston and continually pushes the piston over to the side of the bore it rides in. When you adjust it, the little screw moves the sector shaft up and down to tighten the lash between the two gear faces. Up is tighter, down is looser. You may get it tight on center and then it will be far too tight as the piston moves into the less worn areas of the bore.

If perchance your mechanic swapped in an A1 Cardone box, there is a high likelihood that it wasn't even rebuilt, just cleaned and painted.

Does this apply to the Mercedes box too?