Need input... found rust in front bumper to frame

[My73]

Welcome pros and experienced body men 

Just bought my 73 mustang. 

Car looked like a fairly clean project. 

A few minor pinholes in the floorboards and you can see where the rear lower quarters were patched years ago. 

Now I’m trying to figure out what I’m looking at, and which section I need to order. 

I see front “inner” and “outer” frame sections. 

This is the section on drivers side that attaches to urethane bumper to the frame. 

 

[Lazarus]

I have a yellow 73 vert that has a beautiful frame and great floors, but those bumper brackets rusted from the inside and split. Mine had some sort of rubber inside and I think if NASA designed a water trap they couldn’t have done a lot better. I was able to repair mine, but I have seen these for sale (on a cougar site I think).

Just wanted to say don’t despair if these are bad, they may not indicate problems elsewhere. 

 

[My73]

I have a yellow 73 vert that has a beautiful frame and great floors, but those bumper brackets rusted from the inside and split. Mine had some sort of rubber inside and I think if NASA designed a water trap they couldn’t have done a lot better. I was able to repair mine, but I have seen these for sale (on a cougar site I think).

Just wanted to say don’t despair if these are bad, they may not indicate problems elsewhere. 

I appreciate the response 

that’s exactly what I see. 

it’s split and you can see that weird rubber. 

honestly the way I found it was I noticed the bumper was just slightly out of alignment on the drivers side. Got underneath and found what I posted. 

if you could get pics of your after the repair or would be much appreciated. 

trying to figure out what I need to do.

 

[Lazarus]

I checked and it looks like the cougar ones are different on the extension piece that comes out of the “box” that attaches to the frame. I did see these on ebay though:

https://www.ebay.com/itm/1973-mustang-front-bumper-brackets/283830842575?hash=item4215a2f4cf:g:MqMAAOSw6INeNM7E

 

[Hemikiller]

Those on the eBay listing are in surprisingly good shape. Best to run them though a bath of molasses or Evaporust to kill what's hiding in the crevices and then saturate with Rust Bullet. BTW - be very careful taking the bolts out that secure the bumper to the arms. Only use hand tools and be nice to them.If they protest and your favorite penetrating oil isn't helping, use an acetylene torch to heat the weldnuts cherry red and the bolts should come out.

You'll probably also find some rot behind the brackets, that's a fairly easy fix if you can weld.

 

[Lazarus]

Those on the eBay listing are in surprisingly good shape. Best to run them though a bath of molasses or Evaporust to kill what's hiding in the crevices and then saturate with Rust Bullet. BTW - be very careful taking the bolts out that secure the bumper to the arms. Only use hand tools and be nice to them.If they protest and your favorite penetrating oil isn't helping, use an acetylene torch to heat the weldnuts cherry red and the bolts should come out.

You'll probably also find some rot behind the brackets, that's a fairly easy fix if you can weld.

GOOD ADVICE that goes for the bolts that go to the frame as well. They are a severe pain if you break free the welded nut in the frame. Ask me how I know...

 

[My73]

Thanks guys. I’m watching that item now.

Those are what is need.

Passenger side is good but driver side is toast.

 

[secluff]

Hello MY73,

  Ford speak for the bumper arms is  "Front Bumper Isolator Arm".  The front bumper arms for the Cougar are different from the Mustang version. Since the Cougar has a metal front bumper and the Mustang a urethane, the bumper reinforcement and arms had design differences.

The isolator was basically a rubber block mounted inside a steel channel and worked fine then since the "Crash" bumpers were something new and the big three were an in a learning curve trying to comply with new government safety regs.

The engineers had no idea that almost 50 years later we would be dealing with a design that held water and would swiss cheese itself. A problem compounded by the fact that the 73 Cougar and Mustang were the last of the first generation of those vehicles and made the arms a one year only part. The 74 Cougar and Mustang were both totally new vehicles with no previous model interchange.

The arms in the E Bay listing posted by Lazarus look to be an exceptional deal. Figuring the attrition rate of this part from accidents, normal wear and tear and the swiss cheese factor and you can see how finding decent functional used versions are becoming tough. 

I would definitely watch the E Bay sale. Considering West Coast Classic Cougar wants almost $160.00 for one Cougar arm, the  E Bay listing for the pair looks pretty good. I would also do as Hemikiller posted and treat them to a good cleansing bath and saturate with some Rust Bullet.

Good luck with your project.  

 

[Lazarus]

Thanks guys.  I’m watching that item now.

Those are what is need.

Passenger side is good but driver side is toast.

Did a nationwide craigslist search and saw these two listings also:

https://tampa.craigslist.org/pnl/pts/d/saint-petersburg-1973-ford-mustang/7089563933.html

https://omaha.craigslist.org/pts/d/homer-1973-mustang-front-bumper-brackets/7060367447.html

the first one has no phone number, which I hate, and the second one is pretty pricey but you might be able to get them to just sell the arms, which should be less than half of the asking, which includes the bumper itself. 

Sorry I don’t have pics of mine, but it had just begun splitting when I caught it; wasn’t quite as deteriorated as the one above. 

Good luck man!

 

[red351]

Not to many years ago I couldn't give them away

 

[MikeGriese]

Was this some kind of solution to the 5 mph bumper impact laws?

 

[secluff]

Mike, this was just the tip of the iceberg. Crash bumpers, EGR valves, and a host of other emission and safety-related items were on the way. These arms were part of the bumper system that was to meet 1973 Federal standards for up to 5 MPH  frontal and 2.5 MPH rear impact protection. Of course, the Government had a list of items that were supposed to remain operational with no damage after an impact.

From what I remember there were two rubber blocks, One on each side of the center I beam. One was bonded to the isolator housing and the other to the center I beam. On impact the I beam moved to the rear stretching the rubber blocks which were designed to absorb about 70% of the impact with the car body taking one for the team and absorbing the rest! By design, the rubber blocks were to return to their normal shape and return the bumper to its original position. (Sounds good on  paper anyway) I was talking to a retired State Trooper I know who remembers working some accidents with these then-new bumpers. When these vehicles were pulled apart by the wrecker driver, the bumpers had a nasty habit of springing back out and injuring anyone that did not have any experience working around these new bumpers!

Just think, the infamous 1974 seatbelt interlock system and 1975 catalytic converters were still on the horizon!

It's sure a good thing our Government was busy protecting us from our selves!!   

 

[My73]

Thanks so much guys.

I appreciate all the input. Hopefully I can find them and fix it.

If not maybe a local welding shop can recreate one?

I appreciate the input. Definitely had me bummed.