85 SD Suspension ID Help, Creaking Sound (Pictures) - Page 2 - PeachParts Mercedes-Benz Forum

BobK · #16 08-29-2006, 10:52 PM

After our phone conversation tonight and then looking at the pictures, I really think you need to get a pro to look at the rust. A failure in that area due to rust could get you or someone else hurt real bad. The local MB Colision Center comes to mind (I know, ouch-but they are good people who really know their stuff).
BTW, in answer to another of your questions, yes lower control arm bushings do go bad. I have a bad one on my 123 right now. I have not replaced it due to not having the correct spring compressor, like we talked about.

SD Blue · #17 08-30-2006, 12:17 PM

Quote:

Originally Posted by 1985 300SD Sady

......What would all the parts include?

......I think I should be able to handle the work... Im 17..........

Should I even attempt to correct the rust issue myself? where do I go for that kind of damage?

.............

While you have it apart, and the spring compressor in hand, I would also change out the lower ball joint and the guide rod mount (the end that attaches to the lower control arm which is a couple of rubber bushings, etc..) The guide rod, shown in WHunter's link, can be a little pricey if ordered as a complete unit. Fortunately, the guide rod bushing(threaded portion) and the large rubber bushings can be purchased separately. However, those large bushings can be a PIA to change out.(all-thread, washers, 3/4 dr. sockets)

Other items to be checked but do not require the spring compressor, are the tie rod ends, idler arm bushings, sway bar bushings, and steering stabilizer. These items I would replace on an as needed basis.

For the rear, it would be good to change out the trailing arm bushings and subframe mounts while you have the spring compressor. The other items can be changed out at any time as needed.

WHunter, will be much better help with the rust issues.

Fortunately, we don't have to deal with that much around here.

Only 17! Just think, you will have many years to enjoy this car and won't need to sit in a tub of epsom salts after doing a lot of suspension work.

1985 300SD Sady · #18 08-30-2006, 04:44 PM

[QUOTE=SD Blue;1262104]

Quote:

Originally Posted by 1985 300SD Sady

......What would all the parts include?

......I think I should be able to handle the work... Im 17..........

Should I even attempt to correct the rust issue myself? where do I go for that kind of damage?

.............QUOTE]

While you have it apart, and the spring compressor in hand, I would also change out the lower ball joint and the guide rod mount (the end that attaches to the lower control arm which is a couple of rubber bushings, etc..) The guide rod, shown in WHunter's link, can be a little pricey if ordered as a complete unit. Fortunately, the guide rod bushing(threaded portion) and the large rubber bushings can be purchased separately. However, those large bushings can be a PIA to change out.(all-thread, washers, 3/4 dr. sockets)

Other items to be checked but do not require the spring compressor, are the tie rod ends, idler arm bushings, sway bar bushings, and steering stabilizer. These items I would replace on an as needed basis.

For the rear, it would be good to change out the trailing arm bushings and subframe mounts while you have the spring compressor. The other items can be changed out at any time as needed.

WHunter, will be much better help with the rust issues.

Fortunately, we don't have to deal with that much around here.

Only 17! Just think, you will have many years to enjoy this car and won't need to sit in a tub of epsom salts after doing a lot of suspension work.

After speaking to whunter on the phone last night... I have made a couple of decisions.

I am just going to replace the upper controls arms, and fix all the rust. I will also do the shocks. I am going to see how this is. If I am still getting noises, I will go ahead and rent the spring compressor and do the rest off all the bushings.

Yes, I am excited with the thought of keeping the car for years to come.

whunter · #19 08-31-2006, 01:23 AM

[QUOTE=SD Blue;1262104]

Quote:

Originally Posted by 1985 300SD Sady

......What would all the parts include?

......I think I should be able to handle the work... I'm 17..........

Should I even attempt to correct the rust issue myself? where do I go for that kind of damage?

.............QUOTE]

While you have it apart, and the spring compressor in hand, I would also change out the lower ball joint and the guide rod mount (the end that attaches to the lower control arm which is a couple of rubber bushings, etc..) The guide rod, shown in WHunter's link, can be a little pricey if ordered as a complete unit. Fortunately, the guide rod bushing(threaded portion) and the large rubber bushings can be purchased separately. However, those large bushings can be a PIA to change out.(all-thread, washers, 3/4 dr. sockets)

Other items to be checked but do not require the spring compressor, are the tie rod ends, idler arm bushings, sway bar bushings, and steering stabilizer. These items I would replace on an as needed basis.

The tie rods and lower ball joints where replaced by me last year.

I agree the guide rod repair kit is an extreme pain to install, even if there is no corrosion, and impossible if there is heavy corrosion inside the socket.

1985 300SD Sady · #20 09-09-2006, 02:59 PM

Last night I finished up all the suspension work.

All new shocks all around (bilstein of course)

New Sway bar links in the rear.

New Steering Damper

2 New Upper Control Arms, and new bushing for the sway bar. (torqued to specs.)

And I got rid of the rust... I welded in new metal, and coated it in that zinc-rich cold galvenizing paint, then primer. I will be undercoating that ASAP.

I got done about 12 midnight... and took it for a spin. Unfortunately my creaking sound did not go away. The car handles a bit differently, and the noises from the rear end went away (because of the sway bar links) I like the way it drives now, but the creaking is driving me nuts.

How else could I determine what needs done? Would using a mechanics stethoscope isolate where the sound is coming from?

Should I replace the sway bar busings on the bulkhead? (under the battery and next to the fusebox)

Was I suppose to use some type of lubrication when putting in the new parts?

Thank you for your response.

sixto · #21 09-09-2006, 03:38 PM

Quote:

Originally Posted by 1985 300SD Sady

Would using a mechanics stethoscope isolate where the sound is coming from?

Kinda hard to do while driving, isn't it?

Sixto
93 300SD

1985 300SD Sady · #22 09-09-2006, 03:42 PM

Quote:

Originally Posted by sixto

Kinda hard to do while driving, isn't it?

Sixto
93 300SD

I meant, someone could be pushing up and down on the car while I check with the stethoscope? would I be able to isolate the sound?

sixto · #23 09-09-2006, 03:53 PM

With everything you've done I would focus on the lower control arm bushings. You should be able to distinguish left from right without a stethoscope then confirm/acquit the lower control arm bushings with a stethoscope. Then move the stethoscope to the guide rod mount bushings... I mean those two big bushings holding the guide rod mount to the frame. Beyond that I'd have to think the frame is compromised.

You might be able to reach in through the wheel wells and apply silicone spray (not WD40) to the firewall swaybar bushings. That might quiet the squeak long enough for you to confirm that you need new bushings.

Sixto
93 300SD

SD Blue · #24 09-10-2006, 09:42 PM

I agree with Sixto. The best route to take might be some silicone spray applied to strictly one component at a time until you locate the creaking noise. The large sway bar bushings would be a good place to start.

Under what conditions do you hear this creaking? Turns? Slightly uneven pavement? Only large bumps such as speed bumps?

Do you "feel" it anywhere, such as your feet? Or does it only turn up as an audible?

pawoSD · #25 09-11-2006, 12:40 AM

My car's suspension is essentially shot, but amazingly it makes 0 sounds no matter what surface I am driving on, dirt roads....paved...potholes....handles pretty well still too, not quite as good as our '83 though. Whatever.

I have decided that at 300k I will rebuild the entire suspension.

(hopefully by then I have a good job + actual money)

1985 300SD Sady · #26 09-11-2006, 03:42 PM

Quote:

Originally Posted by SD Blue

I agree with Sixto. The best route to take might be some silicone spray applied to strictly one component at a time until you locate the creaking noise. The large sway bar bushings would be a good place to start.

Under what conditions do you hear this creaking? Turns? Slightly uneven pavement? Only large bumps such as speed bumps?

Do you "feel" it anywhere, such as your feet? Or does it only turn up as an audible?

I have done that, more than once. I have tried using silicone spray (very liberally ) on each bushing, then push down on the car and the noise is still there.

When I used the mechanics stethoscope last night, the noise was loudest around the lower control arm inner bushing.

This noise happens when there is a change of weight distribution in the car. In other words, the noise occurs when I brake very hard at all, or take turns. Rarely the sound occurs under acceleration. It does not happen when there is a sudden change in the road.

I can not 'feel' the noise in my feet... it is only audible. Definitely from the drivers side, but until I used the stethoscope I couldnt tell which bushing was making the sound. As stated previously, the sound occurs the loudest around the lower control arm bushing.

1985 300SD Sady · #27 09-11-2006, 03:44 PM

I have decided to take the car to a local indie shop that my uncle used to work at and see if they can diagnose it for me.

I would hate to go through replacing the lower bushings and not fix the problem.

SD Blue · #28 09-12-2006, 10:49 AM

[QUOTE=1985 300SD Sady;1273274]........ then push down on the car and the noise is still there.

When I used the mechanics stethoscope last night, the noise was loudest around the lower control arm inner bushing.

This noise happens when there is a change of weight distribution in the car. .............QUOTE]

If you can hear it, especially with a stethoscope, by just pushing down on the car, then things will be much easier. From what you are saying, it sounds as if you have located your problem.

That bushing is a little unique and due to the "flats" on the rubber, some corrosion has probably made its home in that area and with the amount of creaking you are talking about, caused the rubber to break free from the inner bushing. Here is a link to a photo:http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1W71C3A361W90MGEUZ&year=1984&make=MB&model=300-SD-002&category=L&part=Control+Arm+Bushing+Kit
I just changed mine out this past winter. It's not too bad. The only difficulty I ran across was one of the bushing end caps took a little convincing to remove.
You will need the coil spring compressor to remove the control arm (Tool Rental Program). Also needed is some silicone grease, all-thread and washers to press the new bushing in place. There is a good write-up in the service manual http://mb.braingears.com

1985 300SD Sady · #29 09-12-2006, 06:50 PM

Just got back from Precision Motorcars.. who has been working on these cars for 30 years.

I talked to the half owner, for quite some time about my car. He is also a diesel lover. He says in all his experience, he has never seen a lower control arm bushing fail and produce the noise I am getting. I told him about all the work I had done by myself, and he seemed impressed.

He says if it was his car he wouldnt worry about it at all.

Is there any harm in letting this go? (aside from the annoyance? )

I am thinking about moving on down the list and focusing on the transmission problems I am having. Advice? Opinions? Suggestions? Anything?

Thanks!

t walgamuth · #30 09-12-2006, 07:15 PM

have you tried squirting some grease into the ball joint boots?

i have a big needle i use to squirt grease into them whenever i think they may need some lube.

tom w