How to Install New Rear Bumper Cover on 107?

[starstruck]

I purchased a new chrome bumper cover to replace the scratched rear one on my '89 560SL (107) w/ U.S. bumpers. Is there a simple DIY method for installation one could walk me through / share with the forum, or must the entire bumper be removed and disassembled / reassembled by a body shop? Thanks in advance for all help and suggestions.

Chris

[Strife]

Here is the quick version. You need to remove the bumper, no practical way around it.

Liquid wrench would be good on all bolts/nuts, and wait a bit and let it do its work.

0. The cover is STAINLESS, not CHROME. It WILL scratch easily. don't remove any protective covering until AFTER installation. DON'T scratch it. Also, it is surprisingly flimsy and will bend easily. Pay close attention to step 13.


1. Remove the 8 bolts for the bumper shocks and the two holding the rubber pieces to the body of the car. The two are inside the trunk, under the carpet and under the battery cover carpeted piece. Hopefully they are not rusted. You will need help holding one end while you remove the last bolts on the other end. Do not allow the body/paint of the car to be scratched while removing the bumper (pull back and down when removing, and bend the rubber ends outward slightly so the bolts don't scratch anything). Liquid wrench would be good on all bolts/nuts and wait for 24 hours first.

2. Working on a padded surface (or even your lawn), remove the rubber end pieces. Don't lose any bolts or washers.

3. Remove the bumper shocks and brackets from inside the bumper, NOTING EXACTLY how they fit into the rubber pieces inside the bumper brackets. Note the orientation of the brackets.

4. Remove the LH/RH bumper extensions.

5. Remove the three rubber strips at the outside face of the bumper that fit inside the groove in the aluminum bumper bar.

6. This is tricky: the stainless cover has tabs that are bent over the bumper bar. CAREFULLY with soft-jawed pliers and a screwdriver (and see step 13 first to do this without damaging the old cover) unbend these tabs.

7. There are at least two screws involved towards the front of the stainless, but I don't remember where they are, under the rubber strips, I think. Remove them.

8. Now, get a wide soft blade between the stainless and the bumper bar and separate the two parts. If you do it right, you won't damage the old cover any further and it will "pop" off. Note that there is foamy insulation tape under the old cover, probably for anti-vibration. Your new cover probably doesn't have this. Obtain some foamy insulation tape of approximately the same thickness from Home Depot, Lowes, etc or you can get it from MB.

9. Clean and treat all metal and rubber parts with appropriate chemicals, clean and paint anything rusted. Take a close look at your rubber parts and consider replacing them if they are bad. Now is the time. The strip at the rear is not expensive.

10. Obtain insulation tape and WITH CARE, install the tape on the new cover approximately where it was on the old cover.

11. Position the new cover over the bumper bar and snap it into place.

12. Replace the screws.

13. _THIS IS IMPORTANT, READ CAREFULLY_. Make or obtain some 3" x 1.5" x 1/4" pieces of plywood or something that will definitely spread out the pressure while bending and pressing the tabs on the new cover in place over the edge of the bumper bar. Failing to do this, you will certainly damage your new $150-300 bumper cover. Put the wood strip(s) between the pliers and top of the bumper cover, and bend the tabs over the lop of the bumper bar securely. DO NOT ALLOW THE PLIERS TO TOUCH THE TOP OF THE BUMPER COVER.

14. Reassembly from this point is the opposite of disassembly. You might consider cleaning the bolt threads and using some locktite blue on the bumper shock bolts. DON'T USE, like the IDIOTS who did body work on my 1985 380SL, locktite RED. This caused me to break the welds on two of the bumper bolt mounts when I removed my bumpers. You might have to use a RUBBER MALLET, NOT a HAMMER, to reinstall the rubber strips at the edge of the back bumper. It is easier to install the rubber strips BEFORE installing the rear rubber extensions. Tighten everything securely because having something come loose while moving would be VERY BAD.

15. Send the old cover to me for de-denting, sanding, and re-polishing. I like to have spares!

[roncor]

Steve, You are the man! What a great, detailed DIY! I have sent him my old ones, and I know he does great work because he is passionate!