need help from my diesel support group.....

[RG5384]

It was a sad sight watchign my father back my 300SD out of the garage to take off tonight. I saw quite a few things that saddened me. Firstly, my back end is waay low, secondly, it was slamming into gear due to the fact my idle has jacked itself up AGAIN to around 1k, thirdly, i heard some sort of knocking noise-not like a rod but something else? , fourthly, when the wheel was turned i hear a sick moaning noise(i knew it was there but didn't realize it was THAT loud), fifthly, the brakes were sqeaking, and that actually might be about it. My car also needs a new rack dampner screw and that knocking has me worried-compressor? So, looking at my partshop magazine here is what i'm looking at
2 ball joints(one known bad) 23.75x2
drag link 38.10
rear subframe mount: 64.18
bilstein shocks: 139.90
rack dampner screw-30$
rear brake pads-17$
rear tranny mount: 22.17

I think thats about it, but all those things add up to over 350$, assuming my compressor isn't bad!!! and this is also assuming i dont have a stuck(250$) caliper! The other problem is, i cannot do most this work myself. I doubt i can do the subframe mounts, and i know i can't do the ball joints. So on top of the 350+ i have to add labor in to alot of this stuff as well! Am i over exagerating the problem or is this all really necessary do you think? i know my rear subframes are bad, i know my right ball joint is bad, my drag link i know has play, the rear tranny mount is shot, the rack dampner screw is shot(screwd all the way in and it needs to go in farther), and i think that my compressor is knocking!!! I'm a little concerned.... do any of these things sound like they need to be done ASAP? or could i wait till say the mid-end of june to do alot of these?
thanks
Ryan

[CJ]

The best thing to do is learn how to work on the car. I was not born with the knowledge to work on cars, I watch car repair shows, used to hang out at mt friend's garage, read repair manuals rom the library even on cars I do not have.

Start small, and work your way up. Some of the repairs you have mentioned woould be good repairs to learn about your car. If you were in Maryland, I could help you.

[RG5384]

thanks cj, i do the majority of the work on my car myself, it's just the suspension and steering work that has me worried. My most recent accomplishment has been replacing the dashboard. I can do the brakes no problem, and im gonna take a look at the subframe mounts to see whats involved when i do my rear brakes. Are ball joints really that hard to do with a press tool?
Ryan

[leathermang]

Ryan, Brakes and Steering are sometimes pretty important things on a car.... so I would suggest your first time on those things being under the supervision of someone with some experience...and use a check list from a good source... particularly on the final tightening..You are right to be worried about doing it correctly... Greg

[RG5384]

steering is the main thing i'm concerned about doing myself. I've done enough brake work in the past to get by safely. Replaced master cylinder, both pads up front, brake booster, replaced pads on my old century, and shoes in the back. Going to be replacing pads/rotors on my dad's bimmer here shortly. I'm truely only concerned about the steering, i can do the brakes i know, and the other stuff can wait. Any insight on the steering systems on these cars? shoudl i just have it done and know it's done right?
Ryan

[Jeff72_220d]

I just replaced the rear pads, rotors, and one caliper/hose on the rear of my 300SD. The pads were about $25; the rotors $25 each; and, the caliper and hose another $145. The time to complete is a couple of hours, if you know (more or less) what you're doing. (I obviously DON'T KNOW WHAT I'M DOING, BECAUSE ONE OF THE BRAKES IS STILL SCRAPING).

The GROANING could be low fluid in the power steering reservoir. The level should be about 3/8" from overflowing. The 300SD is known to groan unless the fluid is kept topped up. Mine sure does make noise when the level is low.

[RG5384]

thanks for the tip on the ps jeff, although i have already checked that. It definately is coming from the right side front wheel, so i'm thinking ball joints or drag link-both which need to be replaced. That was the first place i looked though, we had an old ford aerostar van that used to need a pint of PS fluid every time you filled up with gas we still have too much PS fluid...
Ryan

[leathermang]

Could you find a mechanic that would let you watch and ask questions ? that would be a great way to start....I worked a summer in a spring and brake shop during college... first as mechanic then up front with the customers.. part of my job was to place the cars in the stalls for the mechanics to work on them,,, it was very interesting to get to drive all those cars that needed front end work,, you get to feeling small things you never noticed before....

[JimSmith]

Ryan,

Don't get discouraged, and pick the jobs to work on one at a time, in the order of how important they are to you. Of all the things you described, the idle control issue and the sagging rear are the only ones that sound like out of the ordinary, and the sagging rear is not really that much out of the ordinary. But it should be fixed.

All the cars I have actually torn into had a pretty much manually adjustable idle control means, with a knob on the dash. My new
Diesel does not have this feature and I suppose yours doesn't either. So, I am not too clued in on how the idle is regulated on your car, so I won't volunteer any advice on that matter.

The rear shock replacement job is pretty simple and straightforward. I jack the car up and put it on jack stands, and use a hydraulic jack to manipulate the position of the trailing arm/suspension. On a W123 model, the rear seat should be taken out to get access to the top of the shock. This is likely the same on the car you have.

Before I start taking the old shocks out, I make sure the suspension is not hanging all the way down. To do this I use the hydraulic jack on the side I am working to push the wheel a few inches up against the springs. This keeps the load of the springs pushing against the suspension off the nuts at the top of the shock.

The upper connection has two, 17mm nuts (that is what they were last time I did this), one that locks the other. Once these are off, a large washer and rubber donut should come off. The lower end has two similar sized nuts or on some models, bolts, that fasten the lower end of the shock to the suspension. Once the fasteners are off, I jack up the suspension a few inches further, then hold the shock with my hand in that position while I let the hydraulic jack down until the top of the shock comes out of its mounting hole. Then you may have to compress it completely to fish it out of the location.

A worn out shock will not be hard to hold in the compressed position or compress it more by hand. The worn shock has relatively little force left to push the shock out to its full length since the gas pressure has bled off as the shock failed.

This is not the case with the new shock. They come with a tie wrap holding them in the compressed position so you don't have to do it yourself. I have tried taking the tie wrap off before I put the shock into the space in the suspension, and this is not the way to do it.

You are better off getting it in there, and, as the last thing before you locate the top connection in its final position, take the tie wrap off.

I use the hydraulic jack to locate the suspension where I want it for the installation sequence as well. I extend the suspension to its maximum travel while putting the shock into position and installing the lower fasteners. I also try to get the most available space for pulling the tie wrap off, but with the tip of the shock in the mount hole so it goes through once the tie wrap is off. This means you jack the suspension up a little to get things lined up for success, and pull the tie wrap off.

Before you put the new shock in, you will want to install the lower rubber donut and washer on it, then go through the steps of feeding it into position and pulling the tie wrap off. Once located the rest of the job is putting the outer rubber donut on, the last washer, and then tightening the fasteners. I have always tightened the upper ones down until they do not go any further, but I have read on one of these forum threads that this is not always correct.

Depending on how long you have gone without a shock change the lower fasteners may be frozen by corrosion. I would recommend a good soak in a penetrating fluid of your choice as I have had to drill out the existing fasteners and install a bolt and nut making the job a long pain in the rear.

I hope all this helps, and is applicable to your vehicle. Good Luck, Jim

I do -most- of my car stuff myself, but the front-end/suspension, I leave to my mechanic. That and air conditioning, and advanced engine work.

[leathermang]

Here is a general tip for pressurized shocks that have a vertical stud at the top.... place a piece of rubber tubing on that stud long enough to reach through the hole the shock needs to go through... then place the shock in position, and when you cut the restraining cord it extends into the hole guided by the piece of rubber tubing...

Ryan,

I'm a novice and am learning as I go. Have done a number of things and so far, so good. I completely redid my front end suspension except for the lower ball joints, which require serious pressure (shop did those). All else was fairly managable with basic tools. Just took time and patience. There are some great instructions on this forum covering the replacement of virtually every rubber piece.

After doing the work I took the car to a very good front end guy and he looked it all over while he was aligning the car. Had no complaints with the work I did.

The one thing to be super careful of is the spring compression. Must do that right as it can be dangerous otherwise. Lots of explanations about that here.

So I say go for it if you have decent competency with tools and puzzles. The result is great. Car's ride is solid and stable again.

Nic
'85 300CD @ 150 k miles