Thanks for all of your input.

I found the spec that does indeed says that about 1 inch of play at the wheel is normal. The connecting plates before the box look OK.

So let's say I was willing to just replace the box with a new or properly rebuilt unit. Would that fix it, and for how long?

$537 on fastlane + labor (how many hours?) at indy shop doesn't seem like too much to me for normal, responsive, and safe steering.

Aaron

Try locating a really good used one. Much better value.

Haasman

Hello - I was wondering how I can tell if my 'upper
control arms blown out'? Driving the car fast down narrow lanes is very interesting as the car steering is so imprecise!
steve

The way to check any front end components is by employing the four P's; push, pull, pry and prod.

The steering box is definitely one of the few achilles heels found on the 123 cars. I had an extra box at one point and did exploratory surgery.

It's been awhile since I did this so I no longer have a clear picture in my head, but basically there are a couple of places that could be adjusted with shim stock cut into a circle. Earlier boxes provided adjustment via threaded pieces, but you would have to use shim stock on these.

I even considered making a sideline business of adjusting and selling on an exchange basis. If I did that it would justify whatever die set I would have to make to cleanly cut shim stock for this use.

Have a great day,

I've been trying to find the answer to this question...lets see if anyone where knows :)

I have a 1981 300SD w126 with overly sloppy steering (its excessive by spec.)
I have a TIGHT steering box out of a 1979 240D (w123)

These look like they MIGHT be interchangeable but possibly not exactly the same. Innards the same? Any ideas?

Part numbers on fastlane are different but....

A pic out of the one from the 240D

Wheel bearings? Seriously though, by spec these need to be adjusted with a dial-in guage. Most people don't use one and apparently they are much more likely to be too loose than too tight.

It is probably the steering box, they all wear with age. I think rebuilt ones run about $600 +/-.

Hello,
You will need to swap the drop arm to make it work, it may not be as *light* as the W126 box, but in my book, that is a bonus.
Hope that helps.
BTW, check ALL the other stuff before condemning the steering box, like the idler arm bushes etc.

.

Replace the steering damper as well.

Yeah I just cannot have this car down for more than a day and if the steering box is bad when I open it up, it seems needless to put it back in while I wait for parts (and also why order the parts if I don't need them anyway?)

The car has 277k miles on it so that box is probably getting there..

Everything externally on it is tight and not even damp with fluid...the box is good other than that terrible dead spot in the middle (the sides are rather tight in comparison)

By not as light you mean just less power assist?

You are the first person to answer directly btw...its been a long haul trying to find out the info I need :D Thank you!

wandering why the MBZ steering box is so cheesy?
 

What happens is owners do not have the 'play' adjusted out when it develops and this excessive play causes the sector shaft gear to wear unevenly-more in the very center of 'straight ahead'. Tightening the adjusting screw to where the 'unworn' areas 'just off-center' are beginning to drag still leaves play when 'on-center'. Over-tightening in trying to remove the 'on-center' play results in excessive drag and gear damage in the 'just off-center' areas and rapid failure.

If the play cannot be sufficiently removed with adjustment, either replacement of the box or rebuilding the box with new gears is required.

Hello,
From what I have been told by the *German tech* that was here in the 1980s to run the MB techs training school, the cars with the Zero Offset front axle geometry, ie W116,123 and 126, place very high loads on the steering boxes and this causes the *premature* wear, like every 100,000miles, you need a new box, but the older W114,115 and 107 front axle DOES NOT do this, so it may be just possible to find a box from a low mileage W107 that is in good shape.
Yes, by *light* I mean the assist will be or at least should be less on a W123 that will have the bigger reaction pistons(smaller reaction pistons=more assist).
Hope that is of some help and does not cause too many sleepless nights agonizing over MB steering boxes :D