NOTE: There is a background/predecessor thread that details the situation with these front seat arm rest shocks at this thread. It may be useful background to read this thread before proceeding with this HOW-TO.
It's a common occurrence for the small hydraulic strut that is embedded within the center armrest on 1992 and later 500E and E500 models to lose its internal pressure, which doesn't allow the arm-rest lid to "self-open" upward when unlatched.
Similarly, it's exceedingly common for the two plastic straps to bend or break from use. These straps limit the travel of the lid and work more or less in conjunction with the hydraulic strut, although the do not REQUIRE the hydraulic strut.
A couple of years ago, our member "ivanned" was able to source a batch of small hydraulic struts from a Chinese manufacturer, and sold most all of them to 500Eboard members. The project is detailed elsewhere on this forum. This is because this strut is not available as a singular part from Mercedes-Benz -- the entire arm rest assembly must be purchased to obtain the strut.
Thankfully, the two plastic movement-limiting straps ARE available -- and inexpensively -- from Mercedes-Benz. I recently purchased four of these straps to replace the worn ones in my own car, and retained two extras for when these replacements break in the future. One of my original straps was completely broken, as shown below, and the other one was imminently ready to break from repeated flexing.
This job requires about one hour to do slowly and correctly. I took the occasion to both replace the hydraulic strut and replace the two plastic straps.
Tools needed for this job:
- medium-size Philips-head screwdriver
- Plastic straps (two needed): 124 973 02 26
- Hydraulic strut: see this thread and/or correspond with member "ivanned"
Doing this job does not require that the entire arm-rest be removed from the car. Rather, the internal, hinged plastic lid/compartment inner assembly can be removed as a unit, leaving the leather outer shell of the compartment attached to the driver's seat.
This inner compartment/lid assembly is held to the outer shell by eight small Philips head screws, that go into the bottom portion of the shell. These are long screws, about 2/3" in length.
The first step is to remove all six of these bottom screws and set them aside. The compartment/lid assembly then lives straight out of the armrest. Take the assembly over to a workbench, preferably with a towel or other clean surface so that parts can be observed.
Here is a view of the removed compartment/lid assembly, sitting on the workbench. One plastic strap has been removed, and you can see the broken half of the other strap still attached to the upper lid.
Here are the broken pieces of the straps, including the intact-but-nearly-broken second strap.
Here is the old, nearly-broken strap next to a new one ready for installation.
Here are a few views of the old "Stabilus" strut, next to the new Chinese sourced strut. In the first and second photos, you can see that the old strut does not want to self-extend. The third photo shows the old strut fully extended out of its housing.
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Here is a view of the ends of the two struts. As you can see, the screw-on end of the new (silver) strut is too wide to fit the slot in the base of the compartment piece that serves as a retention slot for the end of the strut. Thus, I had to use my bench grinder to grind down both edges of the end piece so that it was flush with the piece with the hole in it. The second photo show me test-fitting the end of the strut during the grinding process, to determine if I'd ground enough off. The last photos show the finished results.
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These next photos are basically a sequence that show the fitment of the strut and the two plastic straps into the bottom compartment and top lid of the arm rest.
The leather portion of the top separates via several short screws and clips, and is carefully prised apart. The plastic movement limiting straps are inserted into their slots on the underside of the lid and twisted into place.
The end of the strut is inserted into the lid, and its retaining pin is inserted. Then the leather portion is carefully snapped back into place, and the screws that hold the plastic inner lid to the leather outer lid are inserted and tightened. This holds the end of the strut and its retaining pin in its slot in the lid.
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A few more views of the above process of fitting the hydraulic strut and movement limiting straps into the lid and compartment.
The compartment is then lowered back into the outer leather shell of the armrest back in the car, and screwed back into place with the longer screws.
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And here is the finished product!!