ah, where to start with what I like to call Project Tank. It all started when I needed a daily driver car for my commute back and forth to work (which is quite a ways). Sure I had my truck, but the terrible gas mileage it got, it was not feasible.
I had been riding my motorcycle back and forth, but it was starting to get a bit chilly. I started looking around at the old Honda Civic and Toyota Camry from the 90’s, when I came to learn about the “Indestructible” Mercedes diesel sedans. Decent gas mileage, easy to work on and are probably up there with Twinkies and cock roaches when it comes to surviving the apocalypse. They have an inline 5 cylinder diesel engine with mechanical injector pump as well as mechanical fuel injection.
I searched Craigslist for a while and ended up finding on and picked it up for $700. Needless to say, if you get a car for $700 you should not expect much from it. See pictures below
The paint wasn’t great and the right rear quarter panel had a dent. The whole car shook when the motor was running and it did not idle very smooth at all. The interior was not in great shape either, but still not to bad for a $700 car.
This car came fully loaded when it was new, power sunroof, A/C, power windows and power locks as well (though can you call them power locks if they run off of the vacuum system?). Another reason I bought the car was that surprisingly all of these things worked even the A/C!
So once I got it home I got to work.
The first thing I noticed was that when I would accelerate, I could feel a vibration from the rear of the car. Upon further examination, I found that the 300Ds came with independent rear suspension, therefore two rear cv axles. The first picture below shows a straight axles and the second picture is of the Mercedes independent axles. These axles had torn boots on them which allowed dirt and foreign particles into the joints which are covered in grease. Naturally the grease grabs the dirt and holds on to it. The joint continues to work, but the dirt particles slowly wear the joint down which can cause the vibrations I was feeling.
For those of you reading that are wondering what the difference is, the independent suspension allows for a smoother ride. For example if you go off a curb on one side, only that side absorbs the impact, where as if you did that in a straight axle you would feel it on both sides.
As you can see the “Cans” on the axle look good as do the rubber boots. These CV axles were relatively straight forward to replace. There is two retainer rings on the ends of the axles inside the “pumpkin” or the differential. Once the differential cover is removed then you can remove the retainer rings and then you can remove the axles from the diff. Where the axles connect to the wheel there is just one nut (I forget the size, but benzworld.org has that info). Once both sides are loose you remove the axle and reverse the process to put in the new ones.
This eliminated the acceleration vibration I was feeling so then it was on to the next problem. The steering wheel had a lot of play in it, meaning I could move it one way or the other before the car actually turned. Upon further examination I noticed the upper control arms, tie rods, center steering rack and the drag link bushings and ball joints were pretty much gone. This is to be expected as rubber is usually pretty deteriorated on these older cars. So I went ahead and replaced all of those things.
These are all of the after pictures with new parts, I lost the before ones when I switched phones.
Next I moved on to the interior and replaced the driver seat since the old one had a torn cover and a couple of broken springs that made the left part of it sag.
Ahh verry nice, made driving it much better. The seats are only held in by 4 10mm bolts and then they lift right out.
The door seals were next along with the door strikers since they were rubber as well, the doors did not like to close all the way and air leaked in to the cabin at highway speeds which was slightly annoying. Door seals are straight forward once you get the old one off. More than likely on older cars the door seals with crumble it to pieces when you try to take them off (kind of like the way the Lanasters did when they fought Daenerys’ dragon…). Once they are off just push the old ones into the slot.
The shaking of the whole car turned out to be the engine mounts. They are hollow and after a while they collapse. To fix this you fill them with a shore hardness 50 polyurethane. The below link is what I used as guidance. This keeps them from collapsing and shaking the entire car.
I also Plasti-dipped the entire car, I had messed with plastidip before, but I had never done a whole car until now. Actually turned out pretty good as plastidip does not run like normal spray paint. Plus its cheap.
Next on the list will be the back window regulators, because my windows keep falling down and I can’t roll them up. There is a plastic gear that gets stripped on the regulator that causes that to happen.
Total I have about $1300 in parts in this car and I use it as my daily driver. I will post more as the project continues.
Thanks for reading!
The Nonconformist's Guide to Engineering 