ADMIN EDIT: Part numbers for the wheel carrier support joint / bushing are discussed in a different thread, click here for details.
I finally decided to install my RDMTek modified rear lower control arms, and perform several other tasks at the same time.
These tasks included:
- Replacing the stock spring pads with "one-bump" spring pads
- Replacing the rear wheel carrier joint bushings
- Replacing the two rubber bushings at the top of the rear struts
- Replacing a lost wheel-housing body panel
- Adjust the parking brakes
- Thoroughly cleaning out the wheel well area of accumulated burned rubber
- Thoroughly cleaning the lower cladding area of accumulated dirt and debris
- Inspecting other chassis rubber and other suspension items for possible future maintenance
The job is not all that hard, physically, but is tedious and takes quite a number of hours. Given the fact that I was also doing so much other work, it took much longer.
I decided to use a spring compressor, for safety purposes, for this job. Some people say that one is not needed, but I choose to do things carefully and "by the book" when it comes to safety.
Among the tools that will be needed:
- 1/4, 3/8 and 1/2 drive ratchets, short extensions and sockets ranging from 10mm to 22mm (10, 13, 17, 19 and 22mm are specifically the ones used)
- Crescent wrench - mid sized
- WD-40, PB Blaster, Liquid Wrench or other penetrant
- 1 can brake cleaner
- 5mm Allen key or Allen socket (preferred)
- 3-4 shop rags
- anti-seize paste
- Blue Loctite
- Syl-Glyde or other lubricant
- needle-nose pliers, bent-nose preferred
- Sledge hammer
- low- and high-range torque wrenches
- various/assorted flat-blade screwdrivers
- eye protection
First of all, while the car is down on the ground ... loosen the lug bolts on both rear wheels.
And then, you need to remove the inner trunk linings on the sides. Don't let ANYONE tell you that 1994 and 1995 E500s weren't made at/by Porsche. Here's proof, once again, on my 1994 car on the inside of the trunk lining.....along with another surprise in my trunk that I'd forgotten about: a rebuilt amp from when the car was a few years old.
Next up, you need to remove the two bolts and the rubber that mount the top of the hydraulic strut to the body of the car. This is inside the car, with a second rubber bushing on the wheel well side of the car; you'll remove this second bushing when you remove the lower control arm later on. In any case, when re-installing these two bolts, the first (lower) one is torqued down to 15-18 Nm, and is then counter-held with a wrench while the secondmost (top) bolt is installed, and torqued to 30 Nm. But that's for re-assembly at the end of the process. Just thought I'd mention it here.
Here are a few photos of the removal of the upper strut mount/bushings, inside the trunk.
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You can see how compressed these upper rubber bushings get, with time and use, as compared to a stock bushing.
Next up, pull the wheel off after raising that side of the car (you can also raise the entire back end). This is what you'll see upon wheel removal.
Everything looked pretty good at first glance with the brake and rotor. You'll want to soak the two large bolts that hold the brake caliper on the wheel carrier for a few minutes, and then loosen them. Mine were fairly easy to remove, but on other cars I own, they have not been quite so easy. Notice that the bolts have blue Loctite; this will be important to remember to put on for re-installation.
Hang the brake caliper so that no strain is put on the brake line. I like to use old clothes hangers, while others I know use bungee cords. Anything works fine as long as you are taking pressure off of the brake line.
It's important to take a break every once in a while. Since this was bright and early on a Saturday morning, a nice large cup of Peet's Major Dickason's Blend coffee was most definitely in order. The cup is a relic of my 8.5 year stint working for Intel, the world's largest manufacturer of microprocessors.
After a bit of refreshment and removal of the brake caliper, it's time to remove the brake rotor. First step is to remove the 5mm allen bolt that holds the rotor to the wheel carrier. Again, notice the blue Loctite.
Removing the rotor itself can be very difficult to do, so I've learned a good technique over the years that has served me quite well. I take a large sledge hammer (think John Henry driving railroad spikes, and you get the idea) and with MODERATE force, I give the face of the brake rotor (where the back-side of the wheel mounts to it) about 10-12 blows in a circular pattern in between the lug bolt holes, generally making about 2-3 circular rotations around the rotor. 80% of the time it will come loose after these blows, though sometimes it does require more. In this case, it took a bit more effort, but the driver's side only took about 7-8 blows to come loose.
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After removing the rotor, take some brake cleaner on a rag, and wipe down the area as good as you can, cleaning up old brake dust and residue. On reassembly, you're going to put a thin coat of anti-seize paste on this surface to help assist removal the next time you have to remove the rotor. Trust me, you'll thank yourself later for taking the small step of applying anti-seize when you re-install the rotor.
Next up, it's time to remove the lower control arm. First of all, remove the two 10mm bolts that hold the plastic cover to the underside of the LCA. Put the bolts and the cover aside; you'll be re-attaching them to the new LCAs once you install them. Then, remove the cover itself carefully; don't snap anything. This plastic is exposed to the elements so it can be quite brittle !!
The next thing you want to do is to compress the spring, so that it's not a factor. I know that some folks say that compressing the spring is not necessary, but I like to render this potentially deadly missile as inert as possible, so I used my Klann spring compressor and compressed it just enough so that it no longer placed any tension on the LCA. After compressing the spring, place your floor jack under the LCA, near or directly under the inboard pivot bolt.
After that, it's time to remove the inboard pivot bolt for the LCA itself. Note that the bushing is a replaceable item, but the RDMTek LCAs (and all factory LCAs) come with these new bushings pre-installed into the LCA, which is a nice touch. The bolt is a 19mm bolt and it can be hard to break loose; torque spec for re-assembly of this bolt is 60 Nm so it's going to be on there pretty good and difficult to break loose. Plus, it's under the car quite a ways so a bit of a stretch to reach. Best to use a 1/2" socket with a breaker bar, and a 22mm wrench to counter-hold the head of the bolt while you remove the nut with the socket.
After the pivot bolt is removed, you can CAREFULLY and SLOWLY lower the LCA, while still maintaining a bit of tension under it with the floor jack. Lower the LCA enough so that you can remove the spring from its carrier. The top of the hydraulic strut should also come out of the hole that goes up into the trunk, exposing the top of the strut and the second bushing that sits just beneath the trunk. See the photos below for some shots of how this bushing gets compressed over time. This is the bushing that really takes the brunt of the wear, so it's the one that is really a good idea to replace. Unfortunately it's bit more work than the one inside the trunk, but it's a good idea to replace both bushings at the same time.
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From there, you can remove the bolt that holds the bottom of the strut to the LCA (a 17mm bolt/nut) and the 13mm bolt/nut that hold the bottom of the sway bar mount to the LCA. These are both simple and straightforward to remove (and install, when the time comes).
Then, it's time to remove the bolt that goes through the wheel carrier bushing. This is a 22mm nut and bolt combo, and requires bending of the brake dust shield for best access, even on later model cars. It CAN be removed without bending the shield, but it's HIGHLY advisable just to bend the shield and then bend it back when done. It will take a bit of adjusting and tweaking to get the shield just right so that it doesn't rub on the rotor, when you do re-install the rotor, so be aware of that.
Here are a few views of my removal of the wheel carrier joint bushing. You can see that it was in EXCELLENT condition after 117,000 miles. I'd be willing to bet that if your car has more than 80K on it, and it hasn't been changed, that it looks something like this too. The interesting thing was that the bushing was extremely floppy and allows for a TON of play. Eek !!! I used a very light coating of Syl-Glyde on the bushing surface and on the rubber to lubricate the installation a bit, and so that the rubber of the bushing didn't get pinched by the installation tool.
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Here I am using the special Baum tool to press OUT the old bushing from the wheel carrier.
And a few views of the bushing itself.
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Using the Baum tool to press the new bushing into the wheel carrier.
And now I turn to the spring. One of my tasks was to remove the stock pad and replace it with a 1-bump pad I had in my stash.
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Then it's time to begin buttoning everything up. Installation is pretty much the reverse of removal.
Re-installing the new RDMTek LCA, with the new 22mm nut and bolt provided with the LCA. MB recommends you replace the nut anyway, so I was grateful for the new hardware.
Re-installing the lower sway bar mount on the LCA, and also the hydraulic strut bottom mount.
Replacing the spring back into the spring carrier. It's highly important that you put the end of the spring back into its little "slot" in the LCA spring area. It is supposed to fit in one place.
And, some additional tasks ... such as using a scraper to lightly scrape off years worth of accumulated tire detritus from numerous burn-outs....some of the rubber was more than 1/4" thick !!
And after I cleaned all of the accumulated dirt and rocks out of the lower cladding under the rear door, and behind the rear wheel, I installed a new plastic panel to replace one that had been missing for many years. I had this panel in my stash but never installed it, for some reason. Well, now seemed the perfect time to do that...