W212 Lower Control Arm Replacement DIY questions

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TeddyRuxpin

TeddyRuxpin

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Regarding the drop links, in my very limited experience I've never seen any drop links that are anything other than 2 bolts/nuts per side.
But doing drop links as a "simple job" has twice required me to use an angle grinder to cut the rusted nuts and bolts off due to being seized in a serious way.
It's simple replacing them after that, having left a couple of coats of black anti corrosion paint to cure on the inevitable bare metal on the anti roll bar from angle grinding.

Crack on Ed and good luck 👍 :cool:

(I just want you to guinea pig this for me please 😉)
Ah thanks! I was worried they’d carry tension when jacked up or something.

I have a trip to Germany and back in mid August and lots of other important stuff that I need the car for so don’t want to risk ballsing anything up before then… I’ll probably tackle it at the end of August tbh!
 

MrGreedy

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Ah thanks! I was worried they’d carry tension when jacked up or something.

It's usually very little tension. Removal is obviously easier.
When refitting and assuming the suspension hub is hanging in the air, you might need to put a second jack under the arm and make some small height adjustment/compression to get the bolts in 100% easily, but they are usually set so that they are near the neutral load position with the hub/wheel hanging in the air; they load up the ARB equally on each side when the car is lowered on to the ground.
 
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You’re a fountain of knowledge my good man. Thanks!

I’m actually looking forward to the day where I have nothing better to do than tackle this! I’ll probably buy one of those 9L oil pumps and a filter and give the car a quick oil change in the meantime, should only take an hour or so.

In the meantime, I’ll probably order those drop links and research the other parts to see if anything else is cheap and ‘easy enough’ to do at the same time.

P.S. for anyone confused, most of those pics I posted earlier are upside down.
 

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The forum software ignores orientation and flipped the photos… what is this 2002 🤣
I've just re-looked at all those pictures with my head up-side-down, and it makes more sense now.

With my W203, you had to detach the hub from the strut (I think it was the strut) for the same job. It's been a few years; memory plus red wine plus bourbon plus ale = foggy.

By the looks of it, you simply crack the E10 (or whatever) bolts and detach from the strut, giving access to that nut on the top of the ball joint bolt.

Get you 1000Nm impact driver prepped, and you'll have this cracked by lunchtime
(after you've completed 6 months of gym workout to be able to manhandle the suspension assembly once it's detached from the strut - I'm signing up with a personal trainer from tomorrow! 👍 )
 

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There was an optional £3.50 payment for up to 200 days return at their cost if the parts not been fitted :)
Just replying to my own comment on Autodoc , I returned some suspension bushes I didn’t need (I had them for a couple of months ) , no problems at all , there was a couple of weeks waiting for them To get back to Germany and a couple of weeks for the money to come back .
 
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Yes, there’s a matching torx bolt on the other side of the strut. I suppose as the car isn’t holding any tension in the damper/strut when jacked up, there’s not much more too it than unbolting those two torx bolts to reveal some more access. No impact gun for me, regular old socket and spanner’s.

I guess I should try to find the torque specs for all of these bolts.

I (evidentially) don’t really understand the mechanics of what’s holding tension to what and I’m still mentally scarred from nearly losing a finger when changing the struts/springs on my old golf gti mk4 (those cheap spring compressors are things of nightmares). I’m happy playing with engines, but suspension terrifies me a bit, and not just because of the price of what Mercedes would charge for a new strut!
 
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I do find the W212 world quite funny in that there isn’t the same wealth of tutorials as there are for other cars I’ve owned. Maybe because they aren’t quite old enough for them to be accessible/cheap to more people, or maybe it’s something to do with the type of person who currently owns one (not the type to tinker with dirty stuff). You’d think there’d be millions of people with tutorials on every aspect but I’ve found it surprising that even something like changing the rear reg plate bulbs was something I had to figure out myself.

There’s a Swedish guy with a channel called MB212 I think, he’s doing some ‘silent’ tutorials.

Maybe I should have made a channel called ‘Clueless Amateur 212 Mechanic’ and become a YouTube millionaire!

Anyway, I digress…
 
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Hi all,

Riving this thread, I have ordered/received the two ARB drop links as they looked easy to change. So I'll be changing the two main lower control arms and the drop links. The drop links were only about £45 delivered, Lemforder. I plan to do this in the next couple of weeks, when I can find the time (and also a location - a place where I can get the car on jack stands!).

Anyone know the torque specs for all the bolts that need to be loosened and replaced?

Namely the ones for the strut which you need to undo to get the control arm out, bolts each end of the control arm, and each side of the drop links?

Thanks!

Ed
 
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Alright, I have the anti roll bar links from Autodoc.... as I won't have a driveway (or the time) to do this on for a couple of weeks, I'm starting to wonder what else I should change 'while I'm there'. Anyone else DIY'd this, what would you recommend? The car is on 160k. I really don't want to do shocks and springs if I don't have to (due to budget).

What about the rears, I never see them mentioned on the 212. All that comes up on youtube is people with S212 and sagging airbags. Anyone changed any rubber in the rear?
 

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Alright, I have the anti roll bar links from Autodoc.... as I won't have a driveway (or the time) to do this on for a couple of weeks, I'm starting to wonder what else I should change 'while I'm there'. Anyone else DIY'd this, what would you recommend? The car is on 160k. I really don't want to do shocks and springs if I don't have to (due to budget).

What about the rears, I never see them mentioned on the 212. All that comes up on youtube is people with S212 and sagging airbags. Anyone changed any rubber in the rear?
Tough one , because the roll bar links are cheap ish . Anything else is all more expensive . On both my cars diy experience I think if you are going to change one or other control arms then you might as well do both (and the bottom ball joint ) , then because you will need tracking doing you might as well change the inner and outer track rods as well .
But if you don’t have any issues and she’s driving ok , just do the drop links and start saving up .
 
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Hi, I already have the big track control arms and the roll bar links for both sides on the front :)
 
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Alright, finally researching this properly - it looks like the front suspension on my W212 E350 pre-facelift (non-airmatic) has the following components:
  1. Lower control arm (£135 pair)
  2. Ball joint (required) for lower control arm (£48 pair)
  3. Upper control arm (comes with ball joint already as part of it) (£150 pair)
  4. ARB drop links (£50 pair)
  5. Spring (??)
  6. Strut (??)
  7. Strut Top mount (£56 pair)
*As a heads up, this is a different configuration to the 211, as it's a mcpherson set up.

As you can imagine, this can get pricey (prices above are Lemforder with Autodoc 40% discount), especially if you purchase the strut and spring. I can't imagine a Mercedes E-class strut is very cheap.

This list obviously doesn't include track/tie rod ends.

I currently have 3 and 4, and I'm thinking of adding just the ball joint and not replacing the lower control arm, but I'm still thinking about it. So I'm currently £200 in parts in, and it's another £183 for me to get the ball joints as well as the lower arms. That would leave just the strut/springs/top mounts/tie rods. But the more you leave for later, the sooner you'll be paying for another wheel alignment.

Sorry for all the posts, just thinking out loud here :D I think I could do with going through this thread from the beginning as there's a lot of good info here.
 
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Ladies, gents? Bueller.... Bueller?

I have a rare window to tackle this job tomorrow, weather permitting, but I can't start unless I know the torque specs for the bolts :D

When I google it, all I get is info on the 211... and this thread!

Anyone able to oblige?
 
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I’m attempting this now/today, I think I know most of the torque settings, but there’s a lot I’m unsure of as I haven’t done this job before. At least it’s not raining…
 

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I’m attempting this now/today, I think I know most of the torque settings, but there’s a lot I’m unsure of as I haven’t done this job before. At least it’s not raining…
Use your torque wrench to measure the torque required to slacken them. Then you have a ball park figure to tighten to.
 
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Thanks for the good idea - I did hear that it could damage the wrench to use it to undo bolts, but that's the least of my problems to be honest... been a nightmare so far. Just trying to do the anti-roll bar drop links today and that's tough enough. The lower bolt is on so tight and there's no room to get anything.

The difficulty with the anti-rollbar drop links is that the lower/rear control arm (on the front of the car - the one I'm not replacing) is completely in your way (for the bottom bolt), so you can't just use a breaker bar/wrench etc. I've got one drop link off on the right side, but the left side is even harder because there's a levelling sensor attached to the control arm (which is already in the way). It would be so much easier with a lift, but on the floor there's just no room to move and get any force on anything.

That's all beside the jacking/jackstand mishap that messed up my sill (it's not too bad...)

I'll be lucky to do the drop links today and then think about the control arms tomorrow.
 
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Also, with regards of torquing the drop links correctly - no chance. You have to hold the middle of the thread with an allen/hex and then tighten with a spanner, so you can't just use a torque wrench with an 18mm socket as it'll just spin... I suppose you have to use the allen/hex on the toque socket but there's just no room at the bottom... not with the tools I have anyway
 
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For doing up these things where the torque wrench won't fit, you could practice torquing up it up on the bench, or a similarly sized fixings (at least, it's got me out of a pickle with my BS EN calibrated arm for DIY spannering :D )

Hold the torque wrench at the same distance as the length you will hold the spanner, and practice so you 'get the feel' of how much 50Nm is (or whatever the required torque).
Then on the car, get an allen/hex socket in the adapter in the end of the breaker bar and wedge the breaker against the floor (so you are only concentrating on moving the spanner). You might want to use a bit of gaffer tape wrapped all the way around the drop link and rear of the head of the breaker socket so it holds the socket firmly in the allen head recess. You should be able to get an open spanner on the nut for 1/3 of a turn and we're not talking hundreds of torques here I presume.
Then do it up by feel. You could then give it a little nip for good measure.

These bolts like most of the stuff under the car are, I presume, low alloy steel rather than e.g. aluminium for the turbo mating like poor @unclebuck was struggling with the other day.
They can take a bit more abuse, so a touch tighter than spec would be good (safe) enough in my view.
Given that this is a drop link and not the suspension arm itself, from a safety point-of-view a detached drop link is not the end of the world should you totally bleep it up. A detached suspension arm would be another matter.

Good luck 👍
 

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T Just trying to do the anti-roll bar drop links today and that's tough enough. The lower bolt is on so tight and there's no room to get anything.

The difficulty with the anti-rollbar drop links is that the lower/rear control arm (on the front of the car - the one I'm not replacing) is completely in your way (for the bottom bolt), so you can't just use a breaker bar/wrench etc. I've got one drop link off on the right side, but the left side is even harder because there's a levelling sensor attached to the contro
Try removing the top bolt first and then pull the AR bar down (or push up) to give you more clearance.
l arm (which is already in the way). It would be so much easier with a lift, but on the floor there's just no room to move and get any force on anything.
Be prepared to improvise.
I'll be lucky to do the drop links today and then think about the control arms tomorrow.
I'd reconsider the timetable. Drop links weren't the priority - arms were. With the arms done, you can re-appraise whether the drop links do actually have to be replaced and, if so, with the arms in place you can consider removing the other arms to gain access to the drop link bolts (if you have to) without the whole assembly being left located only by the strut and track rod end.
 

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