Steering Clunk Noise on Merc-Benz 1973 280SE4.5

I asked for a 60000 mile service on my 1973 280SE 4.5 MB. The MB dealer refused because they no longer have service techs familiar with old cars. I went back to them a week later stating that there was a clunking sound when I turn the steering from straight to either right or left. One time sound during the turn but louder in the right direction.The service manager said it could be the tie rods or ball joints and the I should bring it in. I did the next day but the service manager was on the road but I demonstrated the noice to another service tech. He drove it to the service area and five minutes later the car was back and the service man said the noise disappeared. Can putting the car on a lift clear the problem or did they something else so that they would not be required to service the 1973 car. I did not go with the car to the lift so I do not know what they did and they offered no info why the noise disappeared. My question is what did they do and is the steering clunk a dangerous condition even tho it is not present now.

[MartinUebermuth]

does the car drive straight ahead?
if you drive into a curve with more force does it slinger or buckle?
if you grab the wheel on top and force it in and out do you feel a play?
if not just grease the front joints and see what is.
Cheers Martin
I dont thnk that it is too hard but keep a look on the tie rod ends.
if your the thread of you tires is going to be unequal you need to look closer.
does your steering wheel has free play?
Cheers
Martin

[carnut]

This car was prone to the steering gear box loosening on the frame. Verify the 3 bolts holding the box to the frame are not loose. Left loose, the frame will crack! Do the front shock rubber bushings look in good shape? They can peel away over the years allowing the upper shock mounting to be loose causing a clunk. Look at the flex joint connecting the steering column to the steering gear box. It can deteriorate as well, causing a clunk as the wheel is turned.

[Tomguy]

I've seen some delays to answers but I think this takes the cake!

dpoch, if you're still around some 7 years and 1 month later, did you figure this out yet?

[nicknack280]

I have this issuie with steering clunk. It only clunks when i turn left to right when i'm stationary or driving very slow and turn the steering wheel.

I'll try greasing the joints, but I doubt that is the issue.

Should I try replacing the tie rod and ball joints first?

He mentioned,
"Flex Join Connecting the Steering column to the steering gear" is there a name to this part?

Originally Posted by carnut

This car was prone to the steering gear box loosening on the frame. Verify the 3 bolts holding the box to the frame are not loose. Left loose, the frame will crack! Do the front shock rubber bushings look in good shape? They can peel away over the years allowing the upper shock mounting to be loose causing a clunk. Look at the flex joint connecting the steering column to the steering gear box. It can deteriorate as well, causing a clunk as the wheel is turned.

[ejboyd5]

The post may be old, but the issue remains current, particularly with regard to the bolts mounting the steering box to the frame. While this was common knowledge in the day (M-B even released a technical bulletin on the subject), it is one of those things that new owners of these cars may not be aware.

[GGR]

As mentioned, these 4.5, and even worse on the 6.3s, are prone to have the chassis rail cracking. This is because the engine is very heavy and a lot of effort is put while turning the wheels when the car is stopped (maneuvering in a parking for example). Check if the three steering box bolts inside the wheel well are properly tightened. Then inspect the chassis rail for cracks around the bolts. Then, engine running, have someone turn the wheels lock to lock while you look at the steering box from the top in the engine bay. If you notice the box moving relative to the rail, you should inspect further.

If all the above is good, jack one front wheel up, grab it at 9 and 3 o'clock and rock it left to right. If you have play, have someone do it for you while you put your fingers on all the ball joints one after the other. You should be able to identify the one which has play. Repeat on the other side.

On the passenger side, the relay arm bushings can wear. In that case, you will feel the play at the bottom of the arm where it meets its holding bracket.

On the driver's side, the coupling bushings between the steering column and the steering box can also wear. Have someone move the steering wheel left to right, and watch from the top if the movement of the steering box relay arm matches the movement of the steering wheel. If not, you may have a bit of play in the steering box itself, or the coupling bushings are shot. On a W108, you may be able to reach the coupling and putting your fingers on it while someone is rocking the steering wheel will help you determine if it has some play.

You may also find some play while shaking the front wheels holding them at 12 and 6 o'clock. But that will more likely be a worn king pin.

[nicknack280]

Great advice. Can't wait to get home to inspect everything. I'll update you on my progress.

Thanks everyone