Let's talk about squeaks, baby! Let's talk about clunks and creaks! - PeachParts Mercedes-Benz Forum

MongooseGA · #1 02-05-2018, 06:39 PM

Hey all,

Some of this may be rambling, just to put thoughts out there to the universe and hope for answers.

So I've been obsessing over getting my 85 300D into new car condition lately. I recently finished a complete front end rebuild (literally, everything up front except torsion bar mounts, more on that later).

Now with the tight front end, I'm hearing new noises elsewhere and more pronounced sounds that existed prior-to.

I've got a "chik-chick" or "clack-squeak" kind of sound that comes up consistently when getting on or off the throttle. The noise varies a bit depending on gear, speed, how heavy I'm on or off the skinny pedal. It's coming from under the car, about middle of the wheel base. Could very possibly be the drive shaft support (have a new one to install) but don't have anyone to help me confirm it. I know the bushing is toast, just not sure if the sound I'm describing is the tell-tale sign of it or if I need to be looking elsewhere.

I've got a sort of crunching/stressing/groaning sound up front right at the firewall, driver's side, when going over soft large bumps like a small wide speed bump. It's from the suspension compressing but I'm not able to duplicate it bouncing the car while stopped. There's also a low pitch rattle in the same location when backing out of my garage each morning. In park it may be audible, but not very. When making harder right-turns, I also hear a popping or groaning sound from this area. Since everything else new up front, I'm thinking these may be the torsion bar bushings?

In my research on this, I have found some people remove the brake booster and some ***** and moan through the job without removing it. Looking in the wheel well, it appears I can access the upper nut on this bushing bracket from below and the lower nut from above, under the booster. Thoughts on this method?

Lastly, I have clunking coming from the rear when the car downshifts coming to a stop. It's possible this is related to or even the same as the "chik-chik" sound's culprit described before. The diff mount is new, aftermarket but does appear to still be in good shape. The trans mount is new and the trans is freshly rebuilt. I don't think it would be from axle shafts, but it could be. All 4 boots are in good shape and I haven't heard the 'clicking' sound that's been described in other threads here. Is it possible I'm looking into a toasted diff, maybe? The diff does leak some around the axles. Not dripping, but there's a residue on the pumpkin and the shafts toward the inner ends. Fluid was just replaced in the last 500 miles.

Next big move is to replace the front torsion bar mounts, whichever method proves best, as well as the trailing arm bushings in the rear, subframe bushings, and rear sway bar links/bushings. I imagine it'd be best to do the drive shaft support and all rear work at once while everything is out.

Any thoughts? This is turning into a long term, piece by piece restoration of a daily driven, 330k+ mile old car.

leathermang · #2 02-05-2018, 06:49 PM

Ru-glyde....check at NAPA...

MongooseGA · #3 02-05-2018, 06:54 PM

Quote:

Originally Posted by leathermang

Ru-glyde....check at NAPA...

I've read about this and sil-glyde (I think from you, earlier today actually)

If my bushings are worn, though, I'd rather replace than band-aid them. Unless, if it's normal or not uncommon for 'good' bushings to make these noises under normal conditions and all that is needed is a lube.If I were to go this route, I'd think it would be pretty easy to squirt on those torsion bar bushings from inside the wheel well, no? Would I be wanting to squirt around the bar inside the bushing, or the outside of the bushing inside the bracket? Or hell, maybe both?

Diesel911 · #4 02-05-2018, 07:45 PM

The bushings on the upper and lower control arms don't actually move. They flex internally on the elasticity of the Rubber. Which is why the orientation of the Bushings and torquing the Bolts on the upper and lower control arms while the wheels are on the ground and the weight of the car is on the wheels.

Junkman · #5 02-05-2018, 09:14 PM

Drive shaft parts you mentioned could cause noise. Fix what you see. Sway bar bushings on both my 84 & 85SD looked brand new so I'm suspicious as to whether yours are really worn.

MongooseGA · #6 02-05-2018, 09:59 PM

Quote:

Originally Posted by Diesel911

The bushings on the upper and lower control arms don't actually move. They flex internally on the elasticity of the Rubber. Which is why the orientation of the Bushings and torquing the Bolts on the upper and lower control arms while the wheels are on the ground and the weight of the car is on the wheels.

Curious...Hm..

I did have the chassis on jack stands for the reinstallation and the torquing. Do you think this could be a cause of the front end noise I'm hearing and, if so, would putting the car on a lift and loosening/re-torquing these parts possibly remedy it?

Quote:

Originally Posted by Junkman

Drive shaft parts you mentioned could cause noise. Fix what you see. Sway bar bushings on both my 84 & 85SD looked brand new so I'm suspicious as to whether yours are really worn.

I think it's pretty likely my "chik-chik" sound with the throttle is the drive shaft bushing. The only reason I'm not totally convinced yet is that a) I haven't been under to confirm during a load and b) it sounds further back than the shaft bearing support, not right in the middle of the car where it should be. The sound is pretty audible, and I've actually heard it echo off of other cars in quiet neighborhoods and noticed others heard it too. I would think if it were the diff itself, it would sound more muted and wouldn't be related to just the throttle inputs. Possibly the same for the axles? Am I off here?

My rear end links don 'look' bad, but with a grab and a shake they do make noise. Not enough that I'm hearing them from the cab, but at like $35 for an OEM pair and 20 minutes, they're worn enough to replace anyway. The bushings, on the other hand, look worse than any others I've taken off the car yet.

Update- I tried a little silicone lube on the torsion bar bushings this evening. The 'crunching' over bumps seemed to diminish. I chose a product that specified it was safe on rubber, but if they fail, I was planning to R+R anyway.

Still with a popping or rattling when the vehicle's front end weight shifts (leaning from one direction to the other) and when braking. It's a little alarming to hear it during braking so I will check the calipers for tightness in the morning. Rotors are new. Torque the crap out of em and used blue loctite when installed as my last set had actually started to loosen

Other than calipers, what might it be?

leathermang · #7 02-06-2018, 11:12 AM

Quote:

Originally Posted by MongooseGA

I've read about this and sil-glyde (I think from you, earlier today actually)

If my bushings are worn, though, I'd rather replace than band-aid them. Unless, if it's normal or not uncommon for 'good' bushings to make these noises under normal conditions and all that is needed is a lube.If I were to go this route, I'd think it would be pretty easy to squirt on those torsion bar bushings from inside the wheel well, no? Would I be wanting to squirt around the bar inside the bushing, or the outside of the bushing inside the bracket? Or hell, maybe both?

Well, clearly the proper way to get rid of a squeak is usually to replace that rubber component... but also.. to FIND which one needs replacing.. the ru-glyde is helpful... only spray ONE at a time... and go test....
but there are some times when one does not need replacing but has an annoying Squeak....

Mxfrank · #8 02-06-2018, 11:44 AM

I occasionally have problems with inner wheel weights on my 190D. They stopped using lead weights a while back, and the new steel weights are a bit larger. They can interfere with the front outer tie rod ends depending on the direction of the wheels. Click-click. If you've rebalance your tires or changed your tie rods, it's worth a look.

MongooseGA · #9 02-06-2018, 01:54 PM

Quote:

Originally Posted by leathermang

Well, clearly the proper way to get rid of a squeak is usually to replace that rubber component... but also.. to FIND which one needs replacing.. the ru-glyde is helpful... only spray ONE at a time... and go test....
but there are some times when one does not need replacing but has an annoying Squeak....

It dawned on me late last night that this was the intent behind your suggestion.

Well, with the silicone lube I used last night I do believe I've confirmed that crunching sound is the torsion bar bushings. So that ended up giving the desired result anyway. I'll order a pair this week.

Anyone have thoughts on replacing the driver's side piece by accessing the bracket bolt through the wheel well? It looks like it should work, I was surprised I hadn't seen it mentioned in my searching.

As for the

Quote:

Originally Posted by Mxfrank

I occasionally have problems with inner wheel weights on my 190D. They stopped using lead weights a while back, and the new steel weights are a bit larger. They can interfere with the front outer tie rod ends depending on the direction of the wheels. Click-click. If you've rebalance your tires or changed your tie rods, it's worth a look.

Yikes, I'd think the shop would have noticed that as soon as they pulled the car off their lift! Fortunately not a concern on mine, at least for now. The 'chik-chik' noise is strictly when on and off the throttle or during transmission shifting, and definitely in the rear of the car. I do need to double check my brakes are all still snug for my front rattle. It sounds like it's at the firewall but I do feel it when braking. Since it became a concern, I drove my other car today and will check into it this evening.

vstech · #10 02-07-2018, 07:55 AM

Quote:

Originally Posted by MongooseGA

Hey all,

Some of this may be rambling, just to put thoughts out there to the universe and hope for answers.

So I've been obsessing over getting my 85 300D into new car condition lately. I recently finished a complete front end rebuild (literally, everything up front except torsion bar mounts, more on that later).

Now with the tight front end, I'm hearing new noises elsewhere and more pronounced sounds that existed prior-to.

I've got a "chik-chick" or "clack-squeak" kind of sound that comes up consistently when getting on or off the throttle. The noise varies a bit depending on gear, speed, how heavy I'm on or off the skinny pedal. It's coming from under the car, about middle of the wheel base. Could very possibly be the drive shaft support (have a new one to install) but don't have anyone to help me confirm it. I know the bushing is toast, just not sure if the sound I'm describing is the tell-tale sign of it or if I need to be looking elsewhere.

I've got a sort of crunching/stressing/groaning sound up front right at the firewall, driver's side, when going over soft large bumps like a small wide speed bump. It's from the suspension compressing but I'm not able to duplicate it bouncing the car while stopped. There's also a low pitch rattle in the same location when backing out of my garage each morning. In park it may be audible, but not very. When making harder right-turns, I also hear a popping or groaning sound from this area. Since everything else new up front, I'm thinking these may be the torsion bar bushings?

In my research on this, I have found some people remove the brake booster and some ***** and moan through the job without removing it. Looking in the wheel well, it appears I can access the upper nut on this bushing bracket from below and the lower nut from above, under the booster. Thoughts on this method?

Lastly, I have clunking coming from the rear when the car downshifts coming to a stop. It's possible this is related to or even the same as the "chik-chik" sound's culprit described before. The diff mount is new, aftermarket but does appear to still be in good shape. The trans mount is new and the trans is freshly rebuilt. I don't think it would be from axle shafts, but it could be. All 4 boots are in good shape and I haven't heard the 'clicking' sound that's been described in other threads here. Is it possible I'm looking into a toasted diff, maybe? The diff does leak some around the axles. Not dripping, but there's a residue on the pumpkin and the shafts toward the inner ends. Fluid was just replaced in the last 500 miles.

Next big move is to replace the front torsion bar mounts, whichever method proves best, as well as the trailing arm bushings in the rear, subframe bushings, and rear sway bar links/bushings. I imagine it'd be best to do the drive shaft support and all rear work at once while everything is out.

Any thoughts? This is turning into a long term, piece by piece restoration of a daily driven, 330k+ mile old car.

So... basically, all the good things and the bad things that will be?

leathermang · #11 02-07-2018, 10:18 AM

Quote:

Originally Posted by MongooseGA

It dawned on me late last night that this was the intent behind your suggestion.

Well, with the silicone lube I used last night I do believe I've confirmed that crunching sound is the torsion bar bushings. So that ended up giving the desired result anyway. I'll order a pair this week.

Anyone have thoughts on replacing the driver's side piece by accessing the bracket bolt through the wheel well? It looks like it should work, I was surprised I hadn't seen it mentioned in my searching.

So just for automotive suspension theory basics.....
the ' torsion bars ' or ' the sway bars' do nothing while going straight down the road... or when turning at slow speeds.... they do not have an intrinsic function with regard to the height of the car or resistance to A Arm movement as an example which A Arm bushings had.. which needed to be installed with the A Arm in the ' working position' to keep from improperly affecting the ride height of the car AND wearing the those bushing out post haste....
The Torsion bar bushings... which I think are more properly called ' sway bar bushings ' ( since some cars like some Chrysler products in the 1970's actually had Torsion bars.. which are ( non coiled )Straight Springs running longitudinally which worked in a twisting motion rather than a compaction of coils...
Only act one end against the other.. of the same spring... when the car tries to tilt to one side or the other... it works against that... not wanting to bend..
So if you have taken care of the Squeak... you may not need to replace the Sway Bars or their bushings...

vstech · #12 02-07-2018, 12:56 PM

Quote:

Originally Posted by leathermang

So just for automotive suspension theory basics.....
the ' torsion bars ' or ' the sway bars' do nothing while going straight down the road... or when turning at slow speeds.... they do not have an intrinsic function with regard to the height of the car or resistance to A Arm movement as an example which A Arm bushings had.. which needed to be installed with the A Arm in the ' working position' to keep from improperly affecting the ride height of the car AND wearing the those bushing out post haste....
The Torsion bar bushings... which I think are more properly called ' sway bar bushings ' ( since some cars like some Chrysler products in the 1970's actually had Torsion bars.. which are ( non coiled )Straight Springs running longitudinally which worked in a twisting motion rather than a compaction of coils...
Only act one end against the other.. of the same spring... when the car tries to tilt to one side or the other... it works against that... not wanting to bend..
So if you have taken care of the Squeak... you may not need to replace the Sway Bars or their bushings...

Mostly correct, but on a w123 and w126, the sway bar also positions the upper control arm.