I just bought an 85 300SD. Runs like a top, but the only thing I can see is there is about an inch of play in the stearing wheel. What is the cause? Is this easily remedied?

I am also curious as to the engine type in this car.

Thanks.

for the play in the _steering_ box, assuming that you've verified that the problem is not caused by a dangerously loose tie rod end. The steering box adjustment, though, requires a certain amount of care and experience, or a good shop manual, since there is a danger of overadjusting it and causing binding in the steering and on some brands even cracking the housing.

gotcha, i am not much on DIY, i just wanted to be informed when i took it in for alignment this morning. thanks.

In my opinion, an inch of play in the steering wheel of this vintage MB means the steering is in like-new condition. They are not rack and pinion - instead they have the old-school steering box.



Ken300D

__________________
--------------------------
1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

understood, but the play makes it kinda wallow around on the highway at speed, my buddy's SD does not have this play.

William,

My '85 300SD was the same way.

I did pretty much everything to get the front-end up to speed just to see how much of the play could be attributed to the box.

I had the box adjusted once at MBA by Donnie. As far as I know, he simply adjusted the same screw (or whatever it is) that you'll hear everyone talking about.

The affect of this was what felt like a tighter steering wheel...because it WAS tighter. But, there was still quite a bit of play.

I then had it adjusted by another MB indy closer to home that informed me that the CORRECT way to make the adjustment was to use MB's documented procedure which requires REMOVING the box and performing torque adjustments to certain things in the box.

He had modified the MB procedure and constructed a jig. After he did it, the *play* is almost NILL!
It certainly cost more to do this than making a quick adjustement, but this procedure WORKS.

He explained to me that adjusting the box the other way ONLY *tightens* the steering but does NOT remove the dead spot (play) in the box. So, there is an illusion of improvement. I'm certainly no expert on this so any rebuttable is certainly welcome.

btw....this indy I speak of says he personally trained Donnie on this procedure.

__________________
Chris
1985 300SD - 'Grace' (198K mi.)
2018 Honda Civic Sport
2018 Honda CRV LX
2010 Honda Fit Sport (RIP)
2013 Honda Accord Sport (Sold)
1996 Lexus LS400 (Retired)
1995 Ford Contour SE (Retired)
1976 Porsche 914 (Sold)
1972 Datsun 240Z (RIP)

Thank you Ck, i printed that to take to the mechanic that has been the only person to turn a wrench on this car since 1989.

Chris, I sure would like to know how it's done and what the jig looks like, as I have played and played with different settings to try and get that inch of dead spot out of my 81 SD to no avail. My 86 Euro SE (the boxes look the same both are 126's) has little or no play at all
making it eiser to drive on the narrow MT. roads where we live...........
William Rogers......

after talking to several mechanics, i learned that if you have to actually get inside the box they concider it a rebuild. they suggested that when the time comes to start at the tie rods and work backwards toward the gear box. i am getting an alignment and wuill find oput if the tie rods are ok.

william rogers: no idea what the jig looks like, sorry.

williamJ:

This is about as close as you can prolly get to being a rebuild w/o it actually BEING a rebuild. It's really more of an extensive calibration.
But, you're on track with working your way back. Since there's a chance that many of the front end bushings/mounts/rubber pieces need replacing ANYWAY...you may as well go ahead and get them changed out and see what's finally left in the steering box play.

For me, the option to pay to have a rebuilt box installed vs paying to have the calibration done was a no-brainer....much cheaper to fix it than replace it.

Chris
'85 300SD

Is the adjustment procedure documented in any manuals for the 123? I have a CD with manuals on it, would there be a description of the adjustment procedure avalable there? Although a re-manned box is expensive, is the actual job of pulling it out and replacing it straight-forward? I too have a fair amount of play that I'd like to remedy. I've been accumulating related parts in anticipation of the work, new idler arm, tie-rods, lower ball joints (uppers and the control are are new). My plan is to crawl around and see what else is replacable. Actually, the digrams in performance products catalog are pretty good and I may use them to help figure out which bushings and all should be replaced too.

I'm not sure if the procedure is in the manuals or not. I have a set of the CDs but haven't looked so it's possible that it is there.
I don't think the removal and install of the box is terribly difficult. I think it's more of a time consuming, dirty procedure; power steering fluid drainage, unhooking lines and linkages kinda thing...but doable to a good DIY'er nonetheless.
Like I've told others and you've prolly already heard too, replace everything else first that you can and then see what you end up with as far as slop in the steering box.
..and ja, the PP diagrams are pretty good. I make reference to them quite often!

Chris
'85 300SD

trying to find someone that knows how to "calibrate" the box is more difficult than finding a rebuilt one. i have called every merc garage in Charlotte none have ever heard of what i described and all of them have working on mercedes for "30 years".

__________________
85 300sd 210k

William,

If you'd like, I can contact the mechanic and ask him for more details regarding the MBZ procedure.

But like you say, even if you have the procedure, if the person who would be performing it has never done it, I'd feel more comfortable spending the money to install a rebuilt box.

Chris
'85 300SD

that would be great. thanks.

__________________
85 300sd 210k