Hi

I'm new to the forum, and new to the whole DIY car repair occupation. Having bought a gorgeous '81 300SD (231kmi) a few weeks ago, I've been spending lots of time working on that car, and even more time browsing the Web in general and this forum in particular to learn how it's done (I've had zero car repair experience prior to buying this car). The car was bought to be a biodiesel car, btw, it's been running on B100 ever since.

First of all, I'd like to thank all forum members to creating such a wonderful resource. It's really been invaluable for me, and I truly learned a lot. Without it, owning a '81 car wouldn't have been anywhere near as much fun (unless one counts taking the car to the dealer to be fleeced as fun, who knows, in a peculiar way it may be).

Having spent a good portion of the last weekend on a seemingly simple task of installing new shifter/shift linkage bushings, I'd like to share my experience, in an effort to spare others of my fate (I've really done it the hard way, like those bad guys in the bar in 'Desperado'). The topic is hardly new (nothing under the sun really is), and with enough determination one can find a lot of this info through searching. I couldn't, however, find all of the necessary stuff layed out in a sufficient level of detail so that a newbie like myself could easily peruse it. The instructions are directly applicable to a W126 w/722.303 automatic transmission, but may be relevant to other cars as well.

How does one know that new shifter bushings are needed? Symptoms include, but are not limited to, the following: sloppy shifter (aka excessive shifter play), buzz/vibration of the shifter stick at certain speeds, metallic clunk when shifting, and neutral switch pseudo-malfunction (when you turn the key to start the car, nothing happens, not even a starter solenoid click; after moving the shifter in and out of Park the car starts just fine). What pushed me over the edge is what could be a completely unrelated problem: my car recently started to fail to lock gears when the shifter is put into Park (sometimes the gear would lock, sometimes the car would roll back and the gears would click but not lock). Before diagnosing this further, I decided that having a firm, sure shifter would at least eliminate an "in-between-shift" as a possible problem. Plus, shifter buzz was seriously annoying. The job is a perfect DIY experience: the parts cost next to nothing, no special tools are really needed, and the benefit is very much tangible. Note how I'm not saying how long the job should take: that's because I don't know. "As long as you want it to" would be an honest answer.

A quick search would turn up a number of threads that discuss replacing 2 shifter linkage bushings located under the car. What is discussed less is replacing the other 4 bushings located inside the shifter box. Yet, these are related, and replacing all of them at once may save one some time and aggravation.

There's 3 kinds of bushings involved in shifter operation (2 of each are needed, Fastlane has all of them). All are made from white/semi-translucent hard plastic:

115 267 09 50 Small bushing, no features, basically just a plastic pipe section. Goes inside the bends of the sping that keeps the shifter pushed to the left (on US cars).
http://img.eautopartscatalog.com/hires/W01331642923OES.JPG?width=300&height=300

115 267 12 50 Larger bushing, with a flange on one end, flat otherwise. Also goes inside the shifter box, on two ends of the thick rod that the shifter stick connects to.
http://img.eautopartscatalog.com/hires/W01331642114OES.JPG?width=300&height=300

115 992 03 10 Medium-size bushing, tapered towards ends, sort of sandwich-shaped. Goes under the care on the shift linkage.
http://img.eautopartscatalog.com/hires/W01331643678FEB.JPG?width=300&height=300

Since the under-car bushings are exposed to the elements, chances are that those will be the first to go. One of them is also relatively easy to replace. On my car (which received its share of neglect from PO) these were completely gone, the long rod (connecting the plate sticking down from the shifter box to the lever plate attached to the transmission on the passenger side) was just hanging loosely, nothing but metal-to-metal contact, producing that worderfully harmonic metallic clunk when shifting. Chances are that replacing these two bushings is all you need. The other 4 bushings cannot be easily inspected, and they also lead an easier life. These's several factors to consider, however. First, if your car is sufficiently old, like mine, odds are all 6 bushings are in a sad shape (even those that you can't see and thus ignore). Second, replacing one of the under-car bushings can be made substantially easier by disassembling the shifter box. The third reason only applies to those who are seriously annoyed by seeing pieces of crap (gum wrap, dead flies, a petrified piece of a french fry to name some examples) sitting on the bottom of the shifter box, so that you can see them every time you shift, but can't easily remove (a shrink would probably have had something to say about the reason #3, had I ever wanted to see one, which I don't, unless it's court-appointed, in which case I probably would other things to worry about... but I digress).

First of all, some form of under-car access will be needed, e.g. through jacking it up and putting it on jackstands. The rear under-car bushing is located roughly under the driver seat, so if the front of the car is raised, a bit of extra height may be needed to provide enough clearance. It's possible to see both ends of the long shift linkage rod without raising the car, so that you can inspect those bushings, but if you don't know when they were last replaced, might as well not bother and just get new ones.

First, get under the car and remove the long linkage rod. It's held in place by two metal circlips. Before you start, note the orientation of the rod, i.e. on which side the circlips are. You can't really attach it the wrong way (and still be able to shift), but you can waste a lot of time trying (yes, it's OK to ask me how I know). If the old bushings are still there, just crush them with pliers and push out, they should come out real easy. It will be easier if the shifter is put in the 'S' position prior to getting under the car (just make sure your wheels are choked and the parking brake is engaged -- as always). Then disconnect the metal lever that's attached to the side of the transmission. It's held in place by a 10mm bolt with a nut and a washer at the bottom of the plate (you'll need counterhold). There's zero spring action in that metal plate, so odds are that removing the bolt alone won't necessarily make the plate easy to pull off. What works is taking a strong flat-blade screwdriver and jamming in the opening on the bottom of the plate where the bolt used to be (that's why it's good to remove the bolt vs. just loosening it). I actually had more trouble putting the plate back on than taking it off, and it took me a while to realize the simple fact that I just need to jam that screwdriver into the opening harder, and the plate will start slipping on/off real easy. Again, note the metal plate orientation; it'd be hard to attach it the wrong way, but I won't say it's impossible. With the plate off, you can get back from under the car, and get busy cramming the bushing into the hole where it's supposed to be (i.e. the hole where the long linkage rod connects to the plate). I've read about various ways of doing this. The bottomline is that the bushing won't just slip in there, it has to be pushed in with a serious amount of force, which can be applied via vice grips/small press/c-clamp/large-jaw pliers, etc. The bushing is also supposed to get "more pliable" when put in boiling water, to the point when it's "easy" to force in. I personally haven't found the latter to be the case, perhaps I haven't used hot enough water. With the tools I got, it was the easiest to force the bushing in by gently hitting it with a ruber mallet, while resting the plate with the bushing on top of a sufficiently large socket to allow the bushing to protrude on the other side. Whichever way you choose, it'll give you a good idea of what it'll be like to install the other bushing in the other metal shifter linkage plate, the one protruding from the bottom of the shifter box, with the said plate staying in place. This is definitely doable, and is not necessarily hard when done right, but one sure can make it hard (I did). The choice here is to just do it, and disregard the other 4 bushings, or take the plunge and disassemble the shifter, in which case the second plate comes out of the car. I've had my cake and ate it two by doing both (I wasn't sure I'd be able to take the shifter apart, so I first installed the second bushing from under the car).

Intermission. Get a beer, then see Part 2.