SL-Class (R231) 2013 on: Discussion on the SL550

SL/R231: Lower control arm replacement, how to.

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old May 28, 2023 | 08:22 AM
  #1  
ToeKneee's Avatar
Thread Starter
Member
Liked
Loved
Community Favorite
 
Joined: Jun 2021
Posts: 96
Likes: 44
R231 SL500
Lower control arm replacement, how to.

Whilst at a charity event in the UK I took advantage of having my SL checked over by PCS (Prestige Car Services, a well respected independent Mercedes garage near Portsmouth) for free and they gave it a clean bill of health apart from the lower left control arm had some movement and needed changing. So I checked the price of the part from my local dealer and also some ebay shops and the price would be £307 for the part. I had already checked on WIS about fitting it and it didn’t seem too hard a job although PCS did say that they often broke ball joint splitters when doing the job. I checked on ASRA which stated that the job should take just over an hour so I decided to do the job myself…….
I arrived at my mate’s workshop at midday and tried to get the car on the two poster lift. I knew that the car was too low for the standard pads to fit under but PCS had advised me to lift the back up at the jacking point and slide the front lift pad under, then remove the jack and slide under the rear pad then do the same the other side and voila, the car was up in the air.
So the order of business is to take off the wheel, then both front engine covers, remove the control arm, refit then covers back on, wheel on and off we go. Once the covers were off I realised it would be easier for me if the rear wheel arch cover was also removed for access so that came off too. First nut to come off was holding the drop link onto the arm, then the nut and bolt holding the spring carrier was removed, then the ball joint nut and it split with ease, fortunately, and finally the nut and bolt holding the control arm to the car and the arm dropped off nicely. Quick check with the new arm to ensure it was identical (something I always do to be sure) and I was onto refitting. Firstly ball joint into its hole then manoeuvre the arm up through the spring holder and into its position in the body, put the bolt through and nut, then nut on the ball joint, bolt and nut through the spring carrier then fit the drop link and nut. Now for the tightening, I put some large blocks of wood on the floor and lowered the car onto them so I could crawl under the car to tighten all bolts at ride height. For info the inner bolt which attaches the arm to the car is rated at 100nm then 180 degrees, the ball joint is 250nm, spring carrier 110nm and 90 degrees and the drop link at 130nm (according to WIS). Finally all covers back on, wheel on and lower the car to the ground and reverse the action of using the jack to get the car off the lift pads. All in it took me 1 hour 45 mins but a lot of that was getting the car on and off the lift.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 12:18 PM.

story-0
New Mercedes-AMG SUVs Arrive With NEW V8 Engine: 12 Things You Need to Know

Slideshow: Mercedes-AMG's updated GLE 63 S and GLS 63 bring a new-generation V8, subtle design revisions, and familiar supercar-rivaling performance figures.

By Verdad Gallardo | 2026-06-17 12:52:51


VIEW MORE
story-1
8 Oddball Mercedes Ideas That Actually Made it to Production

Slideshow: Mercedes has never been afraid to experiment, and some of its strangest ideas turned out to be surprisingly successful.

By Verdad Gallardo | 2026-06-10 17:43:40


VIEW MORE
story-2
Dubai Tuner Gives the Mercedes G-Class An Entirely New Look

Sideshow: A Middle Eastern tuner has transformed the Mercedes-AMG G 63 into an open-top special, replacing nearly every exterior panel in the process.

By Verdad Gallardo | 2026-06-10 15:29:50


VIEW MORE
story-3
Six Gift Ideas Your AMG Loving Dad or Grad Will Cherish

Slideshow: Six gift ideas your AMG loving dad or grad will cherish.

By | 2026-06-03 17:26:18


VIEW MORE
story-4
7 Craziest Things AMG Gas Ever Built

Slideshow: Sometimes AMG builds fast sedans. Other times, it builds twin-turbo V12 land missiles and six-wheeled off-road monsters.

By Verdad Gallardo | 2026-05-26 17:59:58


VIEW MORE
story-5
New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

Slideshow: Mercedes-AMG's new electric GT 4-Door Coupe trades combustion for software, synthetic noise, and more than 1,100 horsepower.

By Verdad Gallardo | 2026-05-20 20:08:15


VIEW MORE
story-6
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-7
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-8
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-9
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE