steering box adjustment

82 500 SL with play in steering. The adjustment is complete, and it made a huge difference in handling. I could tell the problem was in the box because I had already renewed the idler arm bushing, ball joints, steering shock and tie rods and there was still too much play -- maybe 2-3 inches in the steering wheel. I had the front end supported on stands. When I grabbed the front wheels at 9 and 3 o'clock and shook back and forth, I could see a 1 to 1 movement in the pitman arm. thus the play was in the box, as the rest of the system was tight. Here is what I did to make the adjustment:

1. remove air cleaner
2. disconnect a/c hose running above left exhaust manifold and set aside (my a/c is not working; be careful with this if yours works. It could open up your system)
3. unfasten the 2 10mm nuts holding the EGR valve onto exhaust man. and lift the whole thing up a half inch
4. now you have clearance to remove the left exhaust heat shield
5. remove left side plug wires
6. due to very tight clearance, i had to jack up the engine about an inch. to do this I removed the 10mm socket head bolts from underneath the motor mounts, removed the 2 10mm fasteners at the top of the fan shroud, and jacked up the engine from the pan using a large block of wood to distribute the weight
7. after several, yes several days of soaking the adjusting screw with PB Blaster, it finally came loose. first, use a 19mm socket with a wobble extension to loosen the surrounding nut. then switch to a crowfoot 19mm to hold it in place while turning the adjusting screw out with a 6mm allen wrench. to do this, I used a 1/4" ratchet with extension and a 6mm wobble female hex socket on the end. I then cut off about a half inch of 6mm allen wrench to put into the socket and into the adjusting screw.
8. i adjusted the screw CCW a quarter-inch at a time and then checked whether I was binding or not. The correct adjustment was a full turn in this case.
9. put everything back together in reverse order.

My steering is now factory-spec 1" play. Between this adjustment and renewing the driveshaft center bearing / carrier, the car is more fun to drive.

Rich Mayer
82 500 SL

[kip Foss]

I'm sure with all you did that you replaced the steering column to steering box coupling. My slc had a lot of play and replacing this coupling made a world of difference. You can see the play by watching the end of the steering column while you rock the wheel back and forth.

Forgot to mention that. Yes, I did change it.

Rich Mayer
82 500 SL

[ctaylor738]

Nice wrench, Rich!

[RickM]

Rich, Thanks for the excellent instructions. I've been putting this job off for quite a while. However I found it to much easier than you describe

On my '85 380 SL all I had to remove was the exhaust manifold heat shield. I then used a breaker bar with extension, wobble/universal adapter and 19mm deep socket. I easily loosened the outside nut. The hex bolt moved along with it. After removing the socket I reached under the manifold with a 19mm open end wrench (approaching from the front of the engine). I positioned the wrench just enough to get hold of the outside nut...just enough to allow me to loosen the hex (allen) bolt without moving the outside nut. Using a ratchet, extension and hex head socket (no need to cut an allen wrench) I carefully loosened the allen bolt. Then I tightened the outside nut with the 19mm socket....worked like a charm. Also, the allen bolt loosened easily. Perhaps beacause my car has always been garaged. I didn't need to use PB Blaster..phew.

Below is the type of hex head socket I used. I've had a cheap set for many years and they come in handy quite often. Harbor Freight sells sets for about $7.

Thanks again...a 3/4 CCW turn got my steering back to perfect.

Rick, sounds like you had an easier time than I did. I wonder if the difference could be attirbuted to different engines and engine sizes...I have the 117.962 which can be pretty tough to work around. I have read that most other MBs are easier to make this adjustment, particularly the diesels. I just drove it again today on a road with curves and terrain. The difference is major.

Rich Mayer
82 500 SL

[RickM]

I'll bet you're right about the different engines. I also saw a non-AC car and the steering mechanism was just staring me in the face...lol

Your well thought out instructions seemed easier than previous examples. That's what inspired me. It's rare that the job turns out to be easier.

[Strife]

Originally Posted by diqmayer

3. unfasten the 2 10mm nuts holding the EGR valve onto exhaust man. and lift the whole thing up a half inch

Rich Mayer
82 500 SL

I have a question on this step. How "bad" is this particular step to do - rusty? Is there a gasket underneath? Must it be replaced? I ask from bad experiences in this area on other cars.

I'm asking for another reason unrelated - in addition to the play, my steering box leaks, so I'm removing the whole darned box and having it resealed/adjusted by an independent MB shop with the right tools, after which I'll replace the center link, rebuild the idler arm (did the tie rods already).

This step was not bad at all. There is no gasket that I saw. There was some very slight surface corrosion. I simply unbolted the piece, lifted it, did my thing, and bolted back on. No apparent leaking and the car is running as well as it did before the removal.

Rich Mayer
82 500 SL

[Captain Scott]

Hi Gang,

After changing the steering coupling in my 74 450SL with 212L, I still have am annoying amount of play in the wheel while driving. Maybe you all can guide me on what to check next.

When the car is cold and not running, the slightest movement of the steering wheel makes the exact same movement of the front wheels. Does this define a gear box adjustment issue like diqmayer documented? Or does it go to a worn gear box?

Scott

Hello,

I'm confused. Isn't a 1-to-1 relationship between the wheels and the steering wheel what you want? In my post, I had a 1-to-1 relationship between the wheels and the pitman arm YET much more movement (looseness?) in the steering wheel itself. Since the movement between the wheels and the pitman arm was proper, I concluded that the looseness had to be between the pitman arm and the steering wheel. Changing the coupling and adjusting the box took away the free play.

Rich Mayer
82 500 SL

[Captain Scott]

Sorry Dig for not being clear.

Yes! 1:1 is what I'm after. But I want it while the tires are spinning!! I have no play at the curb with the engine off. Does that mean the gears are NOT worn?? Once I start and pull away, I get the play. So it is either the box adjustment or the gearing is worn. I've just yet to get the tools and try to get at the outer nut/inside hex bolt try adjusting it. But for my, my PS pumps started to whine at idle while turning in the parking lots. Since I changed the filter and it didn't help, it may be time to exchange the pump itself...

S

Originally Posted by diqmayer

Hello,

I'm confused. Isn't a 1-to-1 relationship between the wheels and the steering wheel what you want? In my post, I had a 1-to-1 relationship between the wheels and the pitman arm YET much more movement (looseness?) in the steering wheel itself. Since the movement between the wheels and the pitman arm was proper, I concluded that the looseness had to be between the pitman arm and the steering wheel. Changing the coupling and adjusting the box took away the free play.

Rich Mayer
82 500 SL

[Tomit1]

well captain, I would say that if you get 1:1 with the steering wheel to tire movement, it means that the gearbox is OK, do not adjust it because it can make things worse.
I think (in order of highest probability) you need to check: front subframe mounts, idler arm bushings, lower ball joints or any ball joints in the steering linkages.

[nobby]

Sorry but I can't help but sympathize with you and your adjustment plight.
There ARE advantages to having a 2.8L
In regards to the EGR question, there should be a $6.00 gasket present.

thanks...I'll get the EGR gasket. If mine had it, it was deteriorated away.

RE: the steering play, what happens when the front end is suspended and you move one of the wheels? See if you can isolate the excess play that way.

Rich Mayer
82 500 SL