Steering Woes

[Michel]

I took my 690SEL for a drive yesterday from Prestons to St Marys and back.
One way was on the M7/M4 and then along Mamre Road to a colleague's house and back via Mamre road/Elizabeth drive and the back roads to my office.

This was my first drive since I had the steering box replaced with a good used one that had been 'kitted'.

I also had an electronic wheel alignement done and my tyres are not that old nor worn.

However, I was and still am experiencing a 'loseness' in the steering.
It appears to be 'notchy' an not smooth between left and right.
For example, on the M4 at 110km/h or so, you are in a straight line and want to change lanes, you tend to veer a lot towards the lane you are going to rather than be precise and the return is just as bad.

That problem is also there at any speed on motorways and normal roads.

This was like that before I changed the box and always thought it was the wear and tear in the stering that was causing it.
I also had the coupling replaced.

Any idea what the problem is?

 

[abl567]

Worn power steering pump?
The logic being the pump is not providing the pressure required to overcome the inertia in a direction change but enough pressure for the forces involved once the inertia is overcome?

 

[Styria]

That doesn't sound good, Michel. A test drive and some form of investigative procedure may be the order of the day. Regards Styria

 

[Michel]

That doesn't sound good, Michel. A test drive and some form of investigative procedure may be the order of the day. Regards Styria

Anytime Godfather.....

 

[Styria]

Well, vene, vidi, vici - to the uninitiated, what does it mean ? Any takers (apart from the 'educated dudes') ? He came, saw and conquered ! Well, not the last bit as Michel and I have diamatrically opposing views on his steering woes. He says one thing, I say something else.

I did drive the 'Red Terror' 690 SEL and apart from the steering having a somewhat heavy feel and possibly lacking proper power assistance, the front wheels stayed firm and felt securely planted, even when negotiating round abouts in an agressive manner. The car felt firm and safe, and it felt much more precise when comparing it with the previous set-up. Sure, in the centre position, there is a little 'free play' but with the kind of test driving I did, I was quite comfortable with it.

Perhaps on Sunday we could have a bit of a test session - you know, you drive this and that, and I drive that and this, and we shall compare, hopefully, fearless notes and arrive at unbiassed and expert decisions and opinions. Well, at this stage, that's my verdict, although I would look forward to getting other opinions as well. Regards Styria

 

[Michel]

I did drive the 'Red Terror' 690 SEL and apart from the steering having a somewhat heavy feel and possibly lacking proper power assistance, the front wheels stayed firm and felt securely planted, even when negotiating round abouts in an agressive manner. The car felt firm and safe, and it felt much more precise when comparing it with the previous set-up. Sure, in the centre position, there is a little 'free play' but with the kind of test driving I did, I was quite comfortable with it. Styria

Worn power steering pump?
The logic being the pump is not providing the pressure required to overcome the inertia in a direction change but enough pressure for the forces involved once the inertia is overcome?

Could that be the answer?

 

[BenzBoy]

If there is any doubt with safety items such as steering and brakes wouldn't it be wise to consult and pay an experienced, qualified Benz mechanic who has knowledge of a W116?
You may recall I looked at and rejected a red S3 which was being re-commissioned by having the brakes renewed? The slave cylinders were bored out/sleeved and replaced in the car so why did they subsequently fail? Because the person doing the job was experienced but not qualified - he bored them out on the bench and of course once they are bolted back in the metal is compressed and so they go out of round. A jig is required to hold them in place with the same tension as when they are in the car before they are bored.
I have just seen the same thing with a motor!! Line bored on the bench without tension on the block. Result? Cylinder bores out of round once back in place and an engine rebuild less that 5000 miles later.....
Regards,
Benz-Boy

 

[John S]

With the comment of 'notchy' my first thought was the cam in the steering box is adjusted a little too tight, with the "veer a lot" problem I would look at the rear wheel location set up - either worn rubbers or slight maladjustment. Slight variations can give a big difference in feel.

 

[Styria]

The brake and engine problems that BenzBoy refers to are quite telling examples what can happen when work is carried out by an experienced, but unqualified tradesperson.

Mind you it bears no relation to the problems, per se, that Michel is experiencing. The steering box was rebuilt by a highly qualified Steering Box expert that's been in business for more years than I care to remember and he is thoroughly familiar with Mercedes Steering Boxes. In fact, Mercedes mechanics take their boxes to him for rebuilding.

The simple fact is that these boxes are all now getting on in age, and chances of gettingt a perfect replacement box are practically nil. It's an age old problem that's been around for years now with no real perfect solution. Should we not remember S-Class who some while ago raided all 116 boxes at one of the wreckers in Johannesburg and they were all scrap - in other words, worn out. The box out of Michel's car had already been rebuilt at some stage (and an incorrect coupling fitted - all prior to his ownership), and not particularly well at that, and it was decreed that it would be best not to use it in its entirety. It just wasn't good enough. Regards Styria

 

[WGB]

Sorry to be pompous but as an ex-latin student - Veni, Vidi, Vici correctly means "I" came, "I" saw and "I" conquered.

The power steering problem is a little unsettling but some random thoughts.

1) The steering link may be rubbing on the back of the sump - make sure you have the correct length 6.9 specific drag link as well as the specific 6.9 pitman arm and idler arms. Anyone being replaced with a 4.5 part will cause problems.

2)Slipping drive belts will cause the same problem.

3) Air in the system

4) Crap in the system partially blocking a port or valve.

After that you get to the expensive bits like steering box or pump problems.

I would also be interested in genuine M-B power steering oil vs Transmission fluid as some of the pundits in teh States consider genuine M-B power steering oil decreases noise.

I also think the 6.9 steering is much heavier than a 450.

Bill

 

[TJ 450]

How are the lower control arm bushes?

Tim

 

[Michel]

How are the lower control arm bushes?

Tim

should be new

 

[TJ 450]

Oh right, I say that because my 450 had a similar characteristic.

It sounds like it must be the box/pump then.

Tim