Clamshell bumpers


2112

Blue/white 06'
Mark II Lifetime
So…. I converted from the solid bumper to the sprung bumper along with my GTG’s clamshell lever bar about 13 years ago.

All was great for the first 9-10 years. Then the rubber cap failed. No problem, I bought spares and I threw another set on. That set lasted about 15 months. I have subsequently replaced them several times with each lifespan becoming shorter.

Last spring I was told Ford was out of stock and that remained the case until my dealer contacted me saying they were back in stock. I thought maybe this meant newly minted and more likely to last years. I installed a set to go to Griot’s Garage C&C which is about a 30 minute drive. The brand new set did not last long enough to make it there in one piece;

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2112

Blue/white 06'
Mark II Lifetime
I tried a couple of suggested fixes and none of them worked for me.

I had my machinist cut me about 25 sets of aluminum replacements.

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You can see a flat was cut in to accommodate where the spring doubles up at the top. There is also a pass through hole if someone wants to powder coat or anodize them (needing to be on a wire). They have a definitive snap into place and are retained by a milled retentive groove. They are a copy of the original OEM rubber piece with the addition of the flat and the recessed area on top for the insert.

I found some heavy bodied felt inserts to act as a cushion. I think the felt is tough enough but the adhesive may not be aggressive enough. I am having some ABS inserts made too. Those can bonded in with 3M 5200.

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TO AWSUM

Ford GT Owner
Mark II Lifetime
Jul 4, 2007
1,512
Niceville FL
I used a grommet similar to these from Home Depot that is smaller on one end (shaped like a mushroom), however, mine is a black rubber grommet about a 1/2 inch diameter. They are usually used to insert in a hole to protect wires going through the hole. On my GT, the small end went inside the spring and the large end covered the top of the spring. It has lasted over 10 years now, much longer than the OEM lasted. Just go to Lowes, O'Reily's, etc. and search through their drawers.
 
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2112

Blue/white 06'
Mark II Lifetime
After talking to the machinist, we are going to modify the aluminum to accept a milled piece of ABS plastic. This will give great surface area to glue the ABS into the aluminum as well as centering the ABS within the aluminum.


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TO AWSUM

Ford GT Owner
Mark II Lifetime
Jul 4, 2007
1,512
Niceville FL
I was in Ace Hardware this morning and saw some rubber "Expansion Grommets" that I think would work very well. A lot cheaper than custom milled bumpers I'd imagine.
 
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2112

Blue/white 06'
Mark II Lifetime
I am positive they are cheaper.

So far, I am at about $30 a set, ( haven't checked into anodizing yet) but I am expecting long term results.

I am into tasteful engine bay upgrades. If you recall, I spearheaded the ARP valve cover bolt upgrade years back.

This recent cover hit home for me

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Yes, being a Ford Engine helped.
 
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TO AWSUM

Ford GT Owner
Mark II Lifetime
Jul 4, 2007
1,512
Niceville FL
Yes, I like a little bling in my engine bay also. Thank you for the valve cover bolts. I have a set. I also changed my OEM fluid caps to chromed caps that are labeled with "Supercharger Coolant", "Radiator Coolant", "5W-50 Synthetic Only" and "Oil Level" dipstick.
 
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2112

Blue/white 06'
Mark II Lifetime
OK, So we are on the same page. :cool:

Yes this is overkill, but it's fun at the same time.
 

KennethClay

GT Owner
Mark IV Lifetime
Oct 15, 2012
883
New York
After talking to the machinist, we are going to modify the aluminum to accept a milled piece of ABS plastic. This will give great surface area to glue the ABS into the aluminum as well as centering the ABS within the aluminum.


Capture.PNG
Put me down for a set, please!
 
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FGT899

GT Owner
Mark II Lifetime
Dec 10, 2013
305
Phoenix, AZ
I've been fighting the same issues for years. I'd take a set as well!
 
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2112

Blue/white 06'
Mark II Lifetime
Got it guys. Machinist is working on ABS now.
 

HighHP

GT Owner
Jun 3, 2019
469
Spokane, WA
After talking to the machinist, we are going to modify the aluminum to accept a milled piece of ABS plastic. This will give great surface area to glue the ABS into the aluminum as well as centering the ABS within the aluminum.
Interference fit - no need for glue. Very nice option for GT owners.
 
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Shark01

GT Owner
Jul 22, 2012
599
Houston Texas
I used a grommet similar to these from Home Depot that is smaller on one end (shaped like a mushroom), however, mine is a black rubber grommet about a 1/2 inch diameter. They are usually used to insert in a hole to protect wires going through the hole. On my GT, the small end went inside the spring and the large end covered the top of the spring. It has lasted over 10 years now, much longer than the OEM lasted. Just go to Lowes, O'Reily's, etc. and search through their drawers.
This is what You did too, there is a comprehensive thread on it if you search……I paid like $2 for the fix (3 years and counting).
 
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2112

Blue/white 06'
Mark II Lifetime
Interference fit - no need for glue. Very nice option for GT owners.

I hope so. I originally suggested a Morse taper of about 5° but I guess machining plastic to that level of accuracy is a bit challenging.
 

2112

Blue/white 06'
Mark II Lifetime
This is what You did too, there is a comprehensive thread on it if you search……I paid like $2 for the fix (3 years and counting).

Agreed, this will not be for everyone.
 

jammer

GT Owner
Mark II Lifetime
Apr 19, 2016
187
Got it guys. Machinist is working on ABS now.
Mine are in excellent shape and look original. Suggest using standard available ABS shape if possible instead of machining one so they can be replaced in the future if necessary. Please put me down for a set. Thank you.
 
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DakotaGT

GT Owner
Mark II Lifetime
Dec 9, 2012
1,715
Sioux Falls, South Dakota
If we're starting a list, I would gratefully purchase a set, too. No issues with mine yet, but nice to be prepared! Thanks Michael.
 
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2112

Blue/white 06'
Mark II Lifetime
I got you guys down. Make sure to P/M me a mailing address.
 
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MTV8

GT Owner
Mark II Lifetime
Jul 24, 2010
1,021
Houston Texas
Overengineering at its finest. I am a fan.
 
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HighHP

GT Owner
Jun 3, 2019
469
Spokane, WA
Why not machine the whole part out of ABS, nylon or UHMW?