Steering Rack Test

[FIBAMAN]

My stealer claims that I need a new steering rack (>£2000 fitted) on my 01 C180 (36,700 miles). He says that they have detected play at the steering wheel on the offside. I can detect no play at all, whether the engine is running or switched off, the slightest movement of the steering wheel results in movement of the road wheels. Can anyone enlighten me as to a more objective test? The car drives and steers perfectly.

 

[television]

My stealer claims that I need a new steering rack (>£2000 fitted) on my 01 C180 (36,700 miles). He says that they have detected play at the steering wheel on the offside. I can detect no play at all, whether the engine is running or switched off, the slightest movement of the steering wheel results in movement of the road wheels. Can anyone enlighten me as to a more objective test? The car drives and steers perfectly.

If as you say there is no play, and the wheels move with the slightest movement
then ignore it, I cant ever recall any post of this nature before and it sounds impossible to me in 35k miles

 

[MIW615]

My stealer claims that I need a new steering rack (>£2000 fitted) on my 01 C180 (36,700 miles). He says that they have detected play at the steering wheel on the offside. I can detect no play at all, whether the engine is running or switched off, the slightest movement of the steering wheel results in movement of the road wheels. Can anyone enlighten me as to a more objective test? The car drives and steers perfectly.

I'm sure one of the more experienced Mercedes experts will chime in soon, however it doesn't sound right to me, especially at that mileage - also I would expect the nearside to show signs of wear before the offside - get a second opinion.

 

[FIBAMAN]

Thanks to all for the speedy reply, my feelings exactly as yours.
Car is going in today to an independant for mot (which was carried out by stealer during the service and was reason given for failure).

 

[MIW615]

Thanks to all for the speedy reply, my feelings exactly as yours.
Car is going in today to an independant for mot (which was carried out by stealer during the service and was reason given for failure).

Keep us posted on the outcome

 

[type49]

You will have to test for excessive play by having the wheels off the ground. By holding the wheel & "wobbling" it up & down checks for play in bearings (adjustable). Wobbling it side to side checks for play in steering/balljoints. If play is detected side to side, a second person is needed to hold ball joints etc to pinpoint exactly where it is coming from. A rack is not a common failure but it is not unheard of. Ask about a goodwill claim due to low mileage.

 

[wireman]

There are 3 places in the rack where slop/play can exist, at each end ball joint (inside the rubber belows), in the rack end support bushes (there may be only 1 end bush some racks use the pinion as one end suport) and at the pinion to rack interface.

It is not reccomended that the rack is repaired due to the percieved risk of it falling to bits afterwards.

The inner track rod ends are somewhat accessible and probably could be sorted with thr rack on a bench.
There are anti rattle spings inside the end ball joints which make it difficult to find slop here, check it on each side with weight on wheels and engine running.

For inner track rod end:- grip the belows gaiter so that your hand is holding both the rack and track rod then get and assitant to move the steering slightly (+/- an inch or two) about the rest position, if there is any play its there where you have trouble, check both sides.
For the support bush (engine not required):- lift and ratle the rack radialy any play requires the rack be stripped to replace the bush.
For the pinion (engine not required):- the assitant will feel lost motion when the steering is very slightly moved (about +/-1/4 inch max). There is always a little lost motion in all power steering systems this is the motion which opens and closes the hydraulic valves that provide the power into the rack hydraulic cylinder.

With the engine stopped and all quiet you may be able to hear any slack being taken up as the steering is shuffled about, if available a stethoscope can be helpfull for this.

The assistant must not move the steering through an apreciable angle whilst you are in contact with the rack or you may be trapped in a very powerful hydraulic mechanism, fingers could be lost if it goes wrong.

If you cant find any slop maybe the Bloke you took it to was trying it on, but do get a second opinion if you have any doubts after you have checked what you can (include fluid level in the checks).

An after thought
There is one more place that could have slop, the steering column has a rubber coupling at the rack end it may be faulty.

However I think that at the milage and age it is unlikly that there is any fault at all.

 

[FIBAMAN]

Wireman that is a very thorough and informative article and very much appreciated. I have just collected the car from my indie (he did any necessary work on my previous C180 WHICH WAS HEAVILY USED BY ME 203,000 miles in 8 years and still going strong for another family member) who has only flagged up 4 corroded brake pipes which require attention (the stealer only flagged up 1).
My confidence in the stealer has greatly diminished and I am starting to wonder what I payed for just to have a merc stamp in the record book.
Once again thanks to all, my heart is beating a little slower tonight. .

 

[st13phil]

<< snip >> [an independant] flagged up 4 corroded brake pipes which require attention (the stealer only flagged up 1). My confidence in the stealer has greatly diminished < snip >>

I'm not trying to justify the differences between the two MOT's but you must appreciate that some "faults" are at the discretion of the tester, so one tester may view wear or corrosion on a particular component as acceptable while another may view it as a fail. If you think the Main Dealer was pulling a fast one with the steering rack then report them to the VOSA who will then inspect your car themselves. But be prepared because they could find the same fault as the Main Dealer...

 

[jberks]

I too have had a car fail an MOT only to be passed by another station. They wanted over £300 to replace a perfectly functional power steering pump. As above, it is down to the personal opinion of the guy doing the test. In fact, most of the MOT is opinion rather than fact. I spoke to VOSA about mine and was basically told that as it's opinion, they can't do anything but advise to get a second opinion. I did and it passed.

 

[and11]

fail is a fail?

I bought a saab last year which already failed mot, i thought this went on computer record and the local mot station i use therefore look this up and deal with the failed areas before passing?

 

[Parrot of Doom]

The moral of the story is to always take your car to be MOT'd at a council MOT station. They have no incentive to find faults other than for safety, as they don't work on vehicles.

 

[st13phil]

The moral of the story is to always take your car to be MOT'd at a council MOT station. They have no incentive to find faults other than for safety, as they don't work on vehicles.

Very true and a policy many people I know stick to.