SLK ride "vagueness"??

[nine468]

Hi folks. Ive not been round these parts for some time, as the car has been performing great..
The car, 51 plate 320 SLK , is my better halfs.
I jumped in it the other day + drove it for a while.
Only to find it seems a tad "vague" + floaty. It feels like some of the suspension bushes have become worn.?? Its not as "tight" as it should be....
Is there a common wear point on the SLK,s.?? ie front wishbones , rear bushes etc etc etc ..???
If so which bushes are the "usual culprits".???
I have access to a VERY good supply of tools + a 2 post ramp , so doing the work is no probs, i just need a pointer in the right dirrection, regarding worn bits..
Any help would be apreciated....Ta.

 

[Rory]

Check the tyre pressures.

...before you start ripping things apart though, are you sure it's not just a relative thing compared to the other cars in your list?

I have a C270 Avantgarde and it sounds just as you described - it's never felt "planted". If you usually drive a 3 Series then they're just in a different league.

 

[nine468]

Hi Rory.
I shouldve mentioned that the tyre pressures were the first thing i checked....30psi front + 33psi rears, as per the handbook...
Ive driven the car recently + over grids + manhole covers it seems to be very unsettled + just not "planted" as i would expect it to be...
Yes my other cars ARE very FOCUSED...
Especially the Porsche 968CS, as that is a Track "toy"...

I have driven the SLK many times in the past, weve had it for about 3 years..+ Ive never realy found it vague . Its only recently its "gone off"...
I hope it is that im used to my other cars, + that way i wonmt have to get "greasy" again...

 

[Uncle Benz]

Tyre pressures, as already said, followed by steering damper. Take it off at one end and it should feel like a 'bullworker'. If it flops back and forth its finished. Leads to floaty and vague steering - makes the car horrible.

 

[nine468]

Yep.
Replaced the steering damper about 8 months ago...

Any more suggestions.???

 

[Uncle Benz]

How many miles has it covered?

 

[nine468]

Approx 65K... Mostly motorway....

 

[antijam]

What wheel/tyre combination do you have fitted? Presumably these haven't been changed since you last drove the car?

My SLK320 has I feel, been rather over-tyred with Pirelli P-Zero's of 225/40–18 ZR on the front and 245/40-18 ZRs at the rear. At speed the grip is phenomenal and the precision is very good, but pottering around town it is very 'unsettled' - as you describe.
I've put this down to the 'tramlining' inevitable from tyres of low aspect ratio and pronounced directional tread pattern, since I haven't found any slackness in any of the suspension components.

Perhaps your car has similar characteristics that you had forgotten after driving rather 'tauter' machinery?

 

[Graham Lee]

Interesting point regarding the tyre sizes and tramlining at low speed.
My 99 SLK is fitted with 17" AMG wheels, 225/45/R17 on the front and 245/40/R17 on the rear. They look great on the car, hoverever the tyres will require replacement next year and I was thinking of replacing the wheels with 16" to give me a better ride. Tyres would be 205/55/R16 on the front and 225/50/R16 on the rear. This I believe is the standard size for the 99 SLK. Any views would be greatly received and where is the best place to purchase these wheels? MB cost, I believe is £150, second hand ? plus refirbishment. Thanks.

 

[antijam]

I'm thinking along the same lines myself, Graham. Apart from the tramlining resulting from the low profile tyres, the ride as you imply is quite harsh.

Also parking next to even low kerbs is fraught with danger, since any contact results either in damage to the rim or to the tyre sidewall - thereby writing off an expensive piece of rubber!

Whilst the 'big wheel' look is aesthetically popular these days, the extra steering precision offered by the stiffer low profile is really only felt to advantage on the track or at illegal speeds on a B road dash - and the recirculating ball steering of the old SLK doesn't make this as much fun as it might be.

Reverting to standard 16" rims ought to make for a more practical and comfortable drive if we're prepared to sacrifice the 'big wheel/rubber band' look....

 

[antijam]

[QUOTE...Tyres would be 205/55/R16 on the front and 225/50/R16 on the rear. This I believe is the standard size for the 99 SLK. Any views would be greatly received and where is the best place to purchase these wheels? MB cost, I believe is £150, second hand ? plus refirbishment. Thanks.[/QUOTE]

Here's a start.... http://cgi.ebay.co.uk/MERCEDES-SLK-...4&_trkparms=72:1301|66:2|65:12|39:1|240:1318-

now all we need is three more........ :-(

 

[Graham Lee]

Thanks for the interest, have spotted this on ebay.
Does anyone know the best place to purchase a 2nd hand set of wheels?

 

[nine468]

Hi chaps.
The car is a standard factory car, with 16" wheels. It has Goodyear GSD F1 tyres all round . They have been on for around 10K miles + have lots of tread left...
I still think the car has become "vague". It seems to skip/"lurch" when driven over smallish potholes .
Just not as ide expect from a Mercedes...
Ill just have to get it on the ramp + do some pocking around with a pry bar + check out the bushes...
I just thought there might be a common weakness that rears its head after a certain time...Like most cars have....

How well do the front wishbones last.???
Are they prone to wearing out joints.??
What about rear bushes ,,,??? etc etc etc ...?????