This noice worries me

[todds]

Hey thanks mercmad, I didn't realize I had to drop the whole thing that much to get the mount out. All the other bits are already off (lower arm, spring, brake hose, etc) That big bolt is in there really tight! I had a breaker bar on it but due to the mouse nest remnants under my aircleaner it had some crud around it and I wasn't confident enough in the purchase to really yank on it. Also my socket extension was an old 1/4 drive. I doused it with some PB Blaster so maybe it'll be better now. I'll have to hit sears for a good 1/2 inch extension and really give it a good turn. Does this bolt go through into the subframe? It seemed to drop down and be married to the mount unlike the 4 little bolts.

[twinockchef]

The large center bolt holds the mount to the sub frame and the four smaller ones hold the mount to the body.
Are you just replacing the sub frame mounts or are you rebuilding the whole front end?

[mercmad6.3]

Hi,Yes,as above ^^ the center bolt is threaded into the top of the crossmember and the mount sits in a little cup. I always advise folks to grease the threads on the new bolt ( mount kits come with new bolts) to prevent rusting up again in future. I have had them break off before today ,so use plenty of penetrating oil to loosen it up . A 1/2 drive is necessary to prevent tool breakage more than anything .
The battery drips acid into the mount on one side and windscreen washer fluid into the other so the mounts suffer over the years.
It is a "must" to have those plastic covers on them to protect the mounts so if yours are missing get a couple from a wrecker or ebay.
If rebuilding the front end I pull the whole front assembly by suspending the engine with a engine crane from above and undo the engine mounts .
This is a good time to check your mounts and radiator hoses,auto trans hoses etc etc because all will now be very visible. The worn chassis mounts cause wear in the accelerator linkages and shifter linkages and the drive shaft flex disc.
It only takes a few minutes to cast an eye over all of this and ensure it is as it should be.
The difference in a Merc that has the front end rebuilt is like night and day.

[todds]

I heard strange old-barge type moaning noises coming from the front rt. corner while turning the steering wheel at low speeds or even stopped. It was pretty consistent and it started AFTER I greased my front end so I figured I'd at least take it apart, clean up any old grease and dirt, inspect for wear and replace the rubber bits. I don't plan on replacing any metal parts or bushings unless something turns up. I feel like what might've happened is that greasing my kingpins caused some old dirt/gunk to get into them and is causing the groaning. I also had a faint crunching or popping sound when the front end went over speed bumps too. At any rate the system is REALLY dirty and caked with hard dirt and the rubber is perished.

After taking it apart this far there appears to be no binding in either of the control arm pivots, they are silky smooth and play-free. The kingpin seems to be smooth and free of play so far too. There is a little play at the top of the kingpin where it attaches to the control arm though, not in the pin itself, but in between the upper pivot and the suspension arm. The subframe mounts are more or less shot, as is the sway bar rubber. 3 Motor mounts and subframe leaf spring bushings are being done as well.

I figured I might as well do it before I lose the time, space and extra funding, although maybe it was that lower control arm carnage you posted that convinced me ;-)

[mercmad6.3]

The noises over bumps will be the chassis mounts. Someone told me once that worst he had ever seen caused the front fenders to lift under hard braking...

There is play in the all the pivots ,excess play means replacing the king pin and the bolts on top. it's available as kit.
The pivots are designed with a little play in them to prevent wear by allowing the grease to move freely . If you can feel movement in them when there spring is loading the bottom arm,( wheel off the ground) then you replace them,otherwise they will be OK.
Your power steering could be sucking air causing the moaning sound. Check the chassis around the steering box too. It's not unusual for cars that spend a lot of time driving in cities to crack the chassis as the front wheels are turned more at parking speeds. Mercedes used to offer a strengthening plate to weld into there but i just make my own to suit .

[todds]

It's definitely not air or the P.S. pump, I know that sound very well. In fact I heard it this morning on the way to work coming from a brand new S600 Wouldn't want to foot that repair bill! At any rate it has nothing to do with the engine and it's most definitely a rubbing/groaning type chassis noise, like an old ship. There's an echo to it through the body :-) It really sounded like the front right suspension area, which is why I tackled it first.

[mercmad6.3]

Check the engine mounts too. I had this once when i bought an exceptionally 300SEL which needed a new trans. allegedly .
The engine mounts were slightly sagged so the engine was sitting on the steering box. When accelerating away from lights a strange sound came from the car as though a bearing had gone in the trans,but only when accelerating.
Replacing the mounts fixed it. With your chassis mounts gone I tend to think it's a similar problem where engine noise is being transmitted into the car.