GTS reflector strip loose - FIX
I found an alternative to the toilet bolts. Lowes sells something called "Elevator Bolts" in their bolt/nut dept (at least our local one). They have an essentially flat round disc for the head which is about 1 1/4 "diameter on a 3/8" bolt. The 2" ones are just long enough to go through holes in the plastic bumper and the steel body section, and be fastened with nuts. I've bonded them to the reflector with Liquid Nails Heavy Duty Construction Adhesive (cleaned/sanded both surfaces well) very near the top of the reflector, with the bolts going through directly below the 2 and T on the bumper. I've let the adhesive dry for a week, and it seems quite strong. I'll install soon, and see what happens.
OK, I know the "adhesive" result. It let loose on one of the elevator bolts within a few days after mounting. Removed the relfector, the other bolt, and all adhesive. I'm now going to the next step, and will use Poxy Weld Industrial formula epoxy (made by Power Poxy) . It proclaims to adhere well to both plastics and metal, and I've had good success with it in the past on items where there wasn't much need for flexing. It does containe Kevlar, one of the items I worked on during development stages, so I have a bit of bias, perhaps!! I'll report back in a week or so about the success of this approach.
Liquid Nails did indicate it wasn't recommended for plastic adhesion. Gotta run experiments, however!!
The differential expansion of the two plastics on the reflector makes the bowing increase in cold and decrease in hot conditions. When the reflector is out, heat the back with a heat gun or hair dryer and it will straighten right out. It will return to the bowed position upon cooling, however, even if you clamp it in the straight position (BTDT). Winter flex bowing is stronger than the tenacity of the velcro "hooks".
Cheers, and THANKS Roger for the idea.
Gary Knox
West Chester, PA
OK, I know the "adhesive" result. It let loose on one of the elevator bolts within a few days after mounting. Removed the relfector, the other bolt, and all adhesive. I'm now going to the next step, and will use Poxy Weld Industrial formula epoxy (made by Power Poxy) . It proclaims to adhere well to both plastics and metal, and I've had good success with it in the past on items where there wasn't much need for flexing. It does containe Kevlar, one of the items I worked on during development stages, so I have a bit of bias, perhaps!! I'll report back in a week or so about the success of this approach.
Liquid Nails did indicate it wasn't recommended for plastic adhesion. Gotta run experiments, however!!
The differential expansion of the two plastics on the reflector makes the bowing increase in cold and decrease in hot conditions. When the reflector is out, heat the back with a heat gun or hair dryer and it will straighten right out. It will return to the bowed position upon cooling, however, even if you clamp it in the straight position (BTDT). Winter flex bowing is stronger than the tenacity of the velcro "hooks".
Cheers, and THANKS Roger for the idea.
Gary Knox
West Chester, PA
Last edited by Gary Knox; Jan 29, 2007 at 03:36 PM.
Originally Posted by Randy V
The problem of the 'bowed out' center reflector strip is due to two things in my opinion. The dissimilar plastics used in the inner and outer halves of the strip cause the strip to warp over time. The velcro attachments weaken, allowing the strip to bow out even further. By the time it becomes obvious that there's a problem, the strip has bowed out so much that the velcro attachments do not have enough 'grip' to restrain it in the flat position.
Here's the easy way to fix it.
First, remove the reflective strip. To do so, remove the tool kit to gain access to the rear light assemblies.
Each light has a large aluminum hexbolt that secures the light in place. Loosen by hand and remove the hexbolt - it should be just finger-tight. You will see that the bolt has a secondary locknut that is used to set the inset depth of the light assembly.
Once the hexbolt is removed, the light assembly can be swung out and removed.
The reflective strip has tabs on either end that sit behind the light assemblies, thus the reason to remove the lights first.
Pull the reflective strip off. It is attached at each and and in the middle by heavy-duty hook-and-loop fasteners (velcro). Trying to replace this with new velcro will not work, as the outward bending force of the now slightly warped reflective strip is stronger than the grip of any velcro material available. Trust me on this one - I first tried several different types, including super-duper marine velcro that is pretty much the same as the original stuff used by Porsche. I even tried using it along the entire length of the strip. No dice.
You will want to use heavy-duty body panel tape such as the stuff by 3M - found at Pep Boys, etc.
Get the wide 7/8" stuff like this:
http://www.cleanacar.com/mmm68.html
A 36" roll of the stuff costs around $12.00 (not the $40+ indicated in that link)
Before you get started, you might want to give the reflective strip an good polishing with some plastic polish, available at any auto parts store. This will remove most scratches and hazing and will make the strip smooth and shiny like new.
Step 1: Remove the original velcro pieces from the back side of the reflector strip AS WELL AS the velcro pieces on the rear body panel. It may take a bit of scraping to get it all off.
Step 2: With some medium sandpaper, rough up the entire backside of the reflective strip AS WELL AS the painted body panel it attaches to. Yes, I know it doesn't seem right sanding that nice shiny paint under there, but once the strip is back in place you'll never see it.
Step 3: Wipe the back side of the strip and the body panel with isopropyl alcohol to make sure it's real clean and let dry thoroughly.
Step 4: Dry fit the strip so you have a good idea of how it will be put in place once the panel tape is on. The reflective strip fits within the bumper indent with very little up/down or lateral movement, so it's pretty easy to get proper placement.
Step 5: Cut two (2) strips of the body panel tape that are almost the length of the reflective strip, leaving them 1 inch short from each end of the strip.
Step 6: Apply the two lengths of panel tape along the length of the reflective strip, spacing them evenly top to bottom, about 1/2" in from the edge. Push the tape down securely along the length, running your hand along the plastic release liner.
Step 7: Once you are satisfied that the tape is securely stuck to the reflector strip, carefully remove the release liner. Pull it back at a sharp angle to prevent pulling the tape off the reflective strip.
Step 8: Place the reflective strip against the body panel, trying to get the middle section to stick first (slightly bowing the strip inward) then working out towards the ends. Using a soft cotton cloth, apply firm pressure along the length of the strip to ensure good adhesion along the length of the strip.
Step 9: Reinstall the light assemblies, adjusting the set nut on the hexbolt as necessary to achieve proper flush mounting of the lens relative to the body.
I performed this fix on my GTS over a year ago. Since then it has been through desert heat, numerous rainstorms and car wash cycles and is still snugly in place.
Here's the easy way to fix it.
First, remove the reflective strip. To do so, remove the tool kit to gain access to the rear light assemblies.
Each light has a large aluminum hexbolt that secures the light in place. Loosen by hand and remove the hexbolt - it should be just finger-tight. You will see that the bolt has a secondary locknut that is used to set the inset depth of the light assembly.
Once the hexbolt is removed, the light assembly can be swung out and removed.
The reflective strip has tabs on either end that sit behind the light assemblies, thus the reason to remove the lights first.
Pull the reflective strip off. It is attached at each and and in the middle by heavy-duty hook-and-loop fasteners (velcro). Trying to replace this with new velcro will not work, as the outward bending force of the now slightly warped reflective strip is stronger than the grip of any velcro material available. Trust me on this one - I first tried several different types, including super-duper marine velcro that is pretty much the same as the original stuff used by Porsche. I even tried using it along the entire length of the strip. No dice.
You will want to use heavy-duty body panel tape such as the stuff by 3M - found at Pep Boys, etc.
Get the wide 7/8" stuff like this:
http://www.cleanacar.com/mmm68.html
A 36" roll of the stuff costs around $12.00 (not the $40+ indicated in that link)
Before you get started, you might want to give the reflective strip an good polishing with some plastic polish, available at any auto parts store. This will remove most scratches and hazing and will make the strip smooth and shiny like new.
Step 1: Remove the original velcro pieces from the back side of the reflector strip AS WELL AS the velcro pieces on the rear body panel. It may take a bit of scraping to get it all off.
Step 2: With some medium sandpaper, rough up the entire backside of the reflective strip AS WELL AS the painted body panel it attaches to. Yes, I know it doesn't seem right sanding that nice shiny paint under there, but once the strip is back in place you'll never see it.
Step 3: Wipe the back side of the strip and the body panel with isopropyl alcohol to make sure it's real clean and let dry thoroughly.
Step 4: Dry fit the strip so you have a good idea of how it will be put in place once the panel tape is on. The reflective strip fits within the bumper indent with very little up/down or lateral movement, so it's pretty easy to get proper placement.
Step 5: Cut two (2) strips of the body panel tape that are almost the length of the reflective strip, leaving them 1 inch short from each end of the strip.
Step 6: Apply the two lengths of panel tape along the length of the reflective strip, spacing them evenly top to bottom, about 1/2" in from the edge. Push the tape down securely along the length, running your hand along the plastic release liner.
Step 7: Once you are satisfied that the tape is securely stuck to the reflector strip, carefully remove the release liner. Pull it back at a sharp angle to prevent pulling the tape off the reflective strip.
Step 8: Place the reflective strip against the body panel, trying to get the middle section to stick first (slightly bowing the strip inward) then working out towards the ends. Using a soft cotton cloth, apply firm pressure along the length of the strip to ensure good adhesion along the length of the strip.
Step 9: Reinstall the light assemblies, adjusting the set nut on the hexbolt as necessary to achieve proper flush mounting of the lens relative to the body.
I performed this fix on my GTS over a year ago. Since then it has been through desert heat, numerous rainstorms and car wash cycles and is still snugly in place.
Great write up Randy,
I found this worked for mine also.
Gary,
Great idea - the "toilet bolt" is dead long live the "elevator bolt"
I like the idea of the liquid nails as it saves a lot of time making the extra washer and drilling the reflector.
Nice one Gary.
Roger
Great idea - the "toilet bolt" is dead long live the "elevator bolt"
I like the idea of the liquid nails as it saves a lot of time making the extra washer and drilling the reflector.
Nice one Gary.
Roger
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."

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From: Insane Diego, California
Originally Posted by cobalt
Great write up Randy,
I found this worked for mine also.
I found this worked for mine also.

Seems some folks are still set on drilling holes into that rear panel though. They probably still use leeches for some home medical remedies...
Use a couple of drops of SEMS panel adhesive(fast set formula) You will not be able to ever get those reflector panels off again , ever. Or use it for the bolts if you go that way. That crap will hold a wheel on!
Kevin,
THANKS for this great suggestion. The epoxy is already on and drying for this attempt. I'll try to get some of the SEM panel adhesive, as I'm always looking for something that bonds plastics and metals extremely well. I appreciate the recommendation and identification of the product.
Gary----
THANKS for this great suggestion. The epoxy is already on and drying for this attempt. I'll try to get some of the SEM panel adhesive, as I'm always looking for something that bonds plastics and metals extremely well. I appreciate the recommendation and identification of the product.
Gary----
As with most of you, my GTS reflector strip doesn't stay attached to the Velocro, but like Alan it isn't bowed out so as of now I'm OK with none of the previously described tricks (for now).
I like to remove my GTS reflector and tail lamps when I wash the car - it is the only way to get the water out so it doesn't drip after driving (I don't have compressed air handy like at the car wash). Decisions decisions ........
I like to remove my GTS reflector and tail lamps when I wash the car - it is the only way to get the water out so it doesn't drip after driving (I don't have compressed air handy like at the car wash). Decisions decisions ........
Finally getting to this.
Now before I go and drill into my bumper/body, thought I'd try Randy's method first.
Went to Amazon and got 3M VHB (very high bonding) tape 5952.
Amazon.com: 3m 2" (50mm) X 6 Ft VHB Double Sided Foam Adhesive Tape 5952 Grey Automotive Mounting Very High Bond Strong Industrial Grade: Office Products
Did a lot of research and this stuff is supposed to be the shizzle. If this sh:t doesn't stick, going to the toilet bolts.
(Working from less to more invasive)
Sceptical to say the least as that reflector was bowed like a mo!
So
Sanded both the body channel area and the reflector, wiped down w alcohol, etc..
Cleaned up the taillight receptacles, plastic polished the taillights, and reflector.
Will report back and see if it's the VHB or Toilet Bolts for the long haul...
Now before I go and drill into my bumper/body, thought I'd try Randy's method first.
Went to Amazon and got 3M VHB (very high bonding) tape 5952.
Did a lot of research and this stuff is supposed to be the shizzle. If this sh:t doesn't stick, going to the toilet bolts.
(Working from less to more invasive)
Sceptical to say the least as that reflector was bowed like a mo!
So
Sanded both the body channel area and the reflector, wiped down w alcohol, etc..
Cleaned up the taillight receptacles, plastic polished the taillights, and reflector.
Will report back and see if it's the VHB or Toilet Bolts for the long haul...


