for those who have replaced the steering box - PeachParts Mercedes-Benz Forum

JHZR2 · #1 03-31-2004, 09:09 AM

Hi,

My 83 300D has a bit of play in the steering box. Ive adjusted it to the point where the play at the center is about 12mm. That is just about where the spec says it should be.

I just made a 2500mi trip to FL and back. The steering was fine for the past month of use, but by the time I got down to FL, the car was wandering quite a bit.

I thought it was cross breezes in FL, and I think a lot of it was, but there still was too much wandering going on. A couple friends drove my car and commented on how funny the steering was, and they understood why I was wandering side to side when going down the road. Granted, these old systems are not like a steering rack setup, but still, a little play is ok; wandering and constant adjustment side to side isnt.

All tires are fine, most all of the front suspension components are new, and so Im thinking that at 222k, its time for replacement. Turning the wheel allows for a lot of movement of the input shaft, but no movement on the output end...

I saw one, sold by carsteering.com that had ended on ebay, no bids. It had free shipping, and the bid was $289. I think I will contact them to see if theyll put another one up, or give me that deal. But I need to know what Im getting into.

How tough is it to replace the steering box in a w123 car? Does the car need to be lifted so the wheels are off the ground? What is involved in removing the pitman arm and then getting it back on in the correct centered location?

Thanks very much!

JMH

MonsieurBon · #2 03-31-2004, 01:36 PM

Please let me know if this works to reduce the play! I am finding the "dead spot" to be INCREDIBLY annoying. I much prefer my old BMW, where it always drifts to the right, but at least it's responsive and predictable!

If this works to reduce play, I will replace my steering box.

So I can check this even when parked? just have someone turn the wheel from side to side and see if output corresponds with input?

Thanks!

JHZR2 · #3 03-31-2004, 01:51 PM

As far as I can tell, if you are to turn the steering wheel (and all the couplings are tight and not causing slop themselves), and the input shaft to the box turns, without any response, or at least some proportional response to the input, then the play is in the box.

I used to be able to turn about 22 mm from side to side, with only minor response in the wheels. Now that I tightened it, I get about 12mm of play, where there is no response. I think this is actually more annoying.

Since I got a good deal on the box, and I have a bit of time, Ill replace it. But Id love some hints/tips/advice from veterans first

JMH

MonsieurBon · #4 03-31-2004, 02:07 PM

My concerns would be how long the crisp steering would last. Can anyone who's replaced the box or driven one of these machines since new offer any experience regarding how long it takes for the steering to get sloppy?

dieseldiehard · #5 03-31-2004, 04:41 PM

If the box has worn internally any attempt to tighten up the response by adjusting the hex screw (CCW to tighten as I recall) will lead to dissapointment soon afterwards. This I was told and this I learned with my '83 300D. It really had a case of wander, maybe some people can live with it but I hated it, wind or no wind I like the car to stay put.
I found a low mileage used steering box at a wrecking yard, installed it and its been fine ever since. Adjustment hasn't been necessary for 6 years since, although that car only gets driven maybe 7500 miles per year, another of my W123's hasn't required any steering box adjustment for as long and maybe triple that many miles.
Normal wear of the steering box is so small that it takes a long time to become noticeable, but if you drive like a taxi service, wear will occur much sooner than if the car sees mostly highway service.
DDH

R Leo · #6 03-31-2004, 04:47 PM

Before dorking with the steering box, make sure that your idle arm bushings are in good shape. Marlene's steering was wonky, I replaced the idle arm bushings and it is an entirely different car to drive these days.

Marlene had about 1" of play and was difficult to keep between the white lines because the play was sort of binary...meaning that when in the area of play, nothing happened. When you deflected the wheel to the limit of the play and actually started to change the steering angle, she would do nothing until you applied some pressure; then you'd get more angle change than you really wanted. At speed, this made you overcorrect a lot.

Replacing the idle arm bushings didn't do away with the play at the wheel. What it did do was make the steering gradually react to changes in the position of the wheel rather than suddenly change direction.

This minute amount of predictibility makes all the difference in the world at highway speeds.

MonsieurBon · #7 03-31-2004, 06:06 PM

I had idler arm bushings, lower ball joints, and I think both lower control arms replaced, and something else I can't recall, and the play was decreased by about 50%, but it's still too much.

So let's hear what needs to be done to replace it!

Thanks!

JHZR2 · #8 03-31-2004, 06:33 PM

Thanks for the replies...

dieseldiehard: since you have some firsthand experience, can you give us a rundown of how to do it?

Thanks,

JMH

JHZR2 · #9 04-01-2004, 06:27 PM

Just bringing this one back up to the top so that hopefully someone, anyone can give me insight as to how to do it without ruining the pitman arm or its connected hardware, and/or the steering shaft... The service manual isnt the clearest, and there are a couple things I dont understand.

Thanks,

JMH