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W124 400E, W126 500SE
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Discussion Starter #1
Is it possible to change the guide rod without removing the whole lower control arm? I very much doubt I'll be able to loosen the nut inside slots. The last time I saw it done it required cutting a hole in the body to get to them - not something I want to do right now.

thanks
 

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1991 300SE W126 Collector owned, maintained 90k mi
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177 Posts
guide rod

Is it possible to change the guide rod without removing the whole lower control arm? I very much doubt I'll be able to loosen the nut inside slots. The last time I saw it done it required cutting a hole in the body to get to them - not something I want to do right now.

thanks
Are the guide rods bent?
 

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Premium Member
1986 420SEL/1995 E300D/4 BMW’s/2 Vanagon’s
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1,026 Posts
Yes, it is, but, you still have to remove the spring to get to the bolt which sits under the spring perch to dettach the front of the guide rod. The rod can be removed by unbolting the subframe carrier bushings at the rear of the guide rod. Then, you can unthread the guide rod from the rear guide rod bushing.
 

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Two '87 570SECs, one '87 560SEL
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4,469 Posts
I'm confused. The nuts "inside the body" are tack welded to a piece of sheet metal that is then inserted inside the chassis. The one bolt that holds the guide rod to the lower suspension arm, as noted, can only be removed when the spring and then the spring perch is removed.

If you need to change the guide rod, you have to remove the front spring sitting on it. If you want to rebuild the dog bones, those can be removed with the guide rod still "stuck" in the lower control arm.

What are you trying to accomplish??
 

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W124 400E, W126 500SE
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Discussion Starter #5
I have horrible clunking in the front end, rubber boots on the guide rod bearings (?) are torn apart so I have to change them.
Sorry if the terminology is not correct, I'm not a native English speaker. I just need to change this: http://www.mercedesmanuals.com/v/vspfiles/photos/126-330-1335-2T.jpg

As I understand it is a joint+bearing and it's setting affects caster. I found some tutorials but they all talk about removing the whole assembly (LCA? is it the same as dog bone?).
If I were to remove the whole LCA, I'd have to loosen the bolts on the bottom retained by the nut with the sheet metal welded. But it (the nut+sheet) comes apart the moment I try to rotate the bolt, and it is a huge PITA to get to it without cutting an opening.

It is quite some time since I had this done (4 years? 5?) and I think we had to drop one side but not the other, maybe because of exhaust? Not sure, but I remember it was NOT an easy job to do...
 

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Two '87 570SECs, one '87 560SEL
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Your English is FAR better than my Czech!! Yes, those are the dogbone pieces. If the captive nuts turn inside the chassis then see if a long nose set of Vice Grips can reach into the hole and grab the nuts.

I just looked at a Generation I 500SEC this morning and the bolt in the LCA is *not* under the spring perch. It can be removed without removing the spring. The Gen II's are the bad ones.

Yes, this will screw up your Caster. Once this is done, you'll have to have a front end alignment. If your 500SE is a Gen II, I have taken off the nut under the LCA, the special washer, and the rubber piece in the LCA, then once unbolting the DogBone (DB) assembly from the chassis, was able to spin it off the end of the guide rod. Mark the guide rod so the new DB can be put back approximately right.
 

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W124 400E, W126 500SE
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Discussion Starter #7
Can someone explain to me how to change it without cutting the chassis open? :/ This is the way everybody does it here...

 

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1991 300SE W126 Collector owned, maintained 90k mi
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177 Posts
captive nuts

Can someone explain to me how to change it without cutting the chassis open? :/ This is the way everybody does it here...

sheer butchery! Obviously performed by someone with little or no mechanical ability or intuition. Yikes!!
I have replaced my guide rod bushings and everything came out perfectly. The trick is: soak the captive nut assy with PB blaster. Then get a open ended wrench and grind it so it's now thin or get a scrap of 3/16 steel and grind an opening to accomodate the nut size. Before using the new nuts I would suggest adding more tack welds to hold the nut to the strap then put in a vise and chase the new bolt into the new nut. This procedure definates cuts down on the stressful twisting action that occurs when tightening the bolts.
Also if you're replacing the GR bushings be prepared for some work. They have to be pressed in.
 
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