Saving the 993 rear bumper cover from grounding damage.

Saving the 993 rear bumper cover from grounding damage. - The bottom edge of the rear bumper cover on the 993 has a forward-facing lip. When it grounds, the lip digs into the pavement and is pulled back, tearing the bumper cover through one of the tailpipe cut-outs, ouch!  Apparently, rear bumper cover grounding, with catastrophic results, is a not-so-uncommon issue with the 993. With a lowered car this can also happen on speed bumps, parking blocks, or most any uneven pavement threshold.

My DIY solution to avoid this issue was to create a 3”+/- wide crescent-shaped sheet metal shield that is positioned so it sits under the bumper cover’s bottom edge. The key to protecting the bumper cover is not to attach it to the cover. This protects the cover from ground-snag shear forces while also isolating it from ground contact.

 On my car, where I no longer use the OE under-engine pan, it is held in place via two L-shaped straps made from 1/2" copper plumbing tubes. The tubes are crushed flat at the ends and drilled through so they can be attached to the bumper cover shield on one end and the two clamp-strap mounting studs of the catalytic converter on the other.

• The straps are attached at one end to the two catalytic converter mounting clamp bolts by adding a couple of nuts to the threaded shank of the bolts; no need to disturb the clamps themselves. 
• On the other end, they can be attached to the metal crescent shield with a couple of machine screws or pop rivets.
• The shield is slightly folded (bent) along its length. This significantly contributes to its rigidity. 
• Don't be too concerned about random dents or kinks in the finished shield when constructing it, as it is not visible once installed on the car, and if functioning correctly, it gets rather beat up anyway from pavement contact.

Catalytic Converter mounting strap studs

Making such a shield is an easy DIY project involving tin snips, some HVAC galvanized steel duct sheet metal or aluminum flashing sheet, and some 1/2" copper tubing purchased at a local DIY store. In the picture above, the shield is bright metal. I have since painted it black with high-heat black spray paint. In either case, it is only visible from under the car. It could be a fun Saturday morning project!

The old shield I fabricated years ago was made of galvanized steel
The shield shows the hits it has taken over many years.

.

UPDATE: Having the shield in place for many years, it has saved me from expensive bodywork on several occasions and shows significant battle scars as evidence of its effectiveness.

Because of its condition, I rebuilt it using aluminum window flashing from a DIY store. Having small irregularities in the sheet metal is not relevant, since the shield will sustain damage from use over time anyway. Took about an hour to fold the sheet flashing to form a double wall, trim it with some tin snips to recreate the subtle curve of the bumper cover skirt, and pop it back on the car using the original straps made earlier. 

The key is to slightly bend the shield and tension it against the bumper cover edge by adjusting the straps so it sits flush against the bottom of the bumper cover. 

As before, I applied a little high-heat black paint, reducing its visibility under the bottom edge of the bumper cover skirt.

The replacement aluminum shield.

If you found this page informative, return to the main page and bookmark it for future 993-related servicing, repair, and upgrading guidance & information. If it saved you aggravation, time, effort, or some coin, consider donating via the button at the top-left corner of this page.