SL 320 suspension question.

[Old Merc]

Re, 1997 SL 320 straight six 24v R129 : Simple question,is the front suspension lower ball joint replaceable? I`m getting two different answers,one is its a ball joint at £24.The other says its a complete arm at over £200 + a lot extra labour.
Any of you early SL experts familiar with this job and its procedure.

[mbtech01]

Please see attached image. You do have the option of replacing just the ball joint (no.62) but you will have to press it out of the lower control arm & the press the new one in as it's an interference fit. If you decide to remove the lower arm to carry out the repair pay close attention to the two large bolts passing through the inner bushes as they may be adjustable & are used to set up camber/caster angles. Don't quote me on this though as i honestly can't remember if they are or not but i'm sure someone will correct me if i'm wrong.
Hope this is of some help & good luck.

[r129sl]

My reading of the EPC is that it depends on whether your car has code 472 (ESP Electronic Stability Programme). Cars with that spec (I can't remember whether EPC was standard on the 320 by 1997 but you'll know) require a new control arm (part no. a1243303407 (left) and 3507 (right), £355 inc VAT each). Cars without have a different control arm (part no. a1243303007 and 3107) with the removable ball joint (part no. A1243330327).

Don't rely on me, I'm often wrong, but that is my reading of the Electronic Parts Catalogue: if you have ESP, you need to change the control arm.

Post your chassis no. and we can check more accurately.

[r129sl]

And the bolts which fit the control arm to the chassis are indeed eccentric to provide adjustment.

[solid61]

Did my bottom ball joints on my 97 sl 320 last year,if you are gonna DIY it you will need a very good spring compressor and a press to put the new joints in the lower arms. This is not an easy job and best left to an expert if you are unsure, i struggled with mine and didnt mark the bottom arm bolts so needed to get a full geometry check done on the car afterwards.One thing i will say is that after the new joints were fitted and the geometry checked and adjusted the difference was amazing.Funny thing is,there was no detectable play in the joints when tested on the car but when removed they were really bad and this was only a month after an MOT pass so definately worth replacing if in doubt.

[Old Merc]

Thanks for all the replies.Your comments on the job confirmed my reluctance to tackle this job myself.
I agree that this is a job for an expert as the resetting of the arms afterwards is essential.My local Mercedes specialist is going to replace both ball joints and adjust the geometry for £370.I think that is a very good price?
I`m glad to see the comment about handling after this type of job was done.My car has always felt "strange" so I`m looking forward to the new feel afterwards.

[r129sl]

New suspension transforms these cars. They eat front anti-roll bar bushes which are pennies to replace.

[solid61]

When i bought my sl,1997 320 sl 112k FSH it drove like it had cross ply tyres.As in it wandered all over the road and followed ruts and had a tendency to understeer quite badly,i have replaced,ball joints,tyres,anti roll bar links, idler arm,steering damper,only after all of these jobs did it drive what i consider to be right.The bggest change was after having the geometry done.All this work was done 10k ago and the roll bar bushes have started to clunk again so ill have to invest another tenner and replace them soon.

[Old Merc]

Update..Lower ball joints,steering idler,center damper all replaced and geometry reset.Your comments are confirmed about handling,it felt like a different car just driving home.It cost £600!!but I consider it money well spent.By the way,Mercedes Indy John Griffiths of Reading did the job,good blokes.

[solid61]

Old Merc said:

Update..Lower ball joints,steering idler,center damper all replaced and geometry reset.Your comments are confirmed about handling,it felt like a different car just driving home.It cost £600!!but I consider it money well spent.By the way,Mercedes Indy John Griffiths of Reading did the job,good blokes.

Pleased to hear it ,money well spent,these cars really need to be properly set up and £600 is pretty good value for the work done.

[m996tt]

Hi,
My car is a 1999 model 280sl . And the car has ESP. I ordered a set
of Lemforder control arms from ECP but I noticed when I took the arms
off that the ball joint ends are slightly different

Can anyone tell me if the earlier design control arms are interchangeable with
the newer model.

[PositronicRay]

I've heard there not although I don't know for sure.

Lemforder don't do the later style arms MB only, they do have different part numbers.

[m996tt]

I have ended up ordering a Febi Bilstein Control arm, they do both part nos.

I have spoke to the supplier and have been assured it is the one for cars with ESP.
So hopefully good to go