Driving without shock tower braces

Hi everyone, I recently discovered that my 71 Grande has suffered from a collision at some point in its life. I found this out when I went to install my stock shock tower braces and the passenger side would not fall into place. The driver side will go in just fine. I took a close look underneath the car and found further evidence of a wreck in the form of warped and mangled metal and non-factory welds.

I'm not sure if it was a bad idea or not, but I took my car for a quick test drive after I finished with my T5 swap.I expected the car to drive odd, but it seemed to drive straight down the road. I didn't have either of the shock tower braces installed. Is driving without them installed dangerous to handling or the condition of the car? I'm guessing it causes some flex, but is it permanent? Also, can you have a unibody car straightened on a frame straightening machine or am I going to need to replace the subframe all together?

Hi everyone, I recently discovered that my 71 Grande has suffered from a collision at some point in its life. I found this out when I went to install my stock shock tower braces and the passenger side would not fall into place. The driver side will go in just fine. I took a close look underneath the car and found further evidence of a wreck in the form of warped and mangled metal and non-factory welds.

I'm not sure if it was a bad idea or not, but I took my car for a quick test drive after I finished with my T5 swap.I expected the car to drive odd, but it seemed to drive straight down the road. I didn't have either of the shock tower braces installed. Is driving without them installed dangerous to handling or the condition of the car? I'm guessing it causes some flex, but is it permanent? Also, can you have a unibody car straightened on a frame straightening machine or am I going to need to replace the subframe all together?

Click to expand...

This is a no no for sure. The unibody construction flexes for sure and with rust eating away in critical areas it gets even weaker. I never start to work on a car without taking it to a frame shop and having it adjusted. Every car will need pulling in some way. I have attached a scan of the Volume 4 body Ford manual that has the dimensions to the "Tooling Holes" and there is one called the M.C.H. Master Control Hole that is what everything on the car is checked from. When the body is welded in the factory they used these holes to align the panels in the weld fixtures. Yes you can align the front wheels even with a twisted frame and the car will drive ok. But you might have fenders, hoods, doors, trunks and convertible tops that do not align properly.

You can jack one of these cars up incorrectly and bend the body. Windshields have been know to crack when jacking up the car incorrectly. A frame shop with new equipment will use lasers to verify and correct the dimensions. If they have the old they will hang gages and measure the dimensions. Do it right and you will have no regrets don't and you might have more issues down the road. I cannot get the file to load it is a scan I might have to do a photo will do tomorrow.

David

I agree with much of what was said above. Since owning these for about forty years, I can tell you that there were times where I had to jack it from the torque box to get the front relaxed enough to get the braces back on. It hasn't been wrecked, I believe that the first time was around 1976, so it was just a few years old and 20k miles. I consider this flex normal.

Yeah not a good idea. I've heard of guys having trouble closing doors just because the shock tower braces were loose. There is way to much body flex in a unibody car to go without any braces.

Thanks for all the information guys, I won't be driving it until I find a shop to straighten the thing. Does your typical body shop have a machine that will do it, or is this more a of specialty item?

Usually an alignment shop that also works with frames is your best bet - they'll have the frame tweaking machine, techniques, and possibly even the specs to get it back into shape. Wouldn't hurt to take the technical drawings provided (just in case they don't have those specs).

As thin and "flimsy" as the export braces seem to be, I find it hard to believe they can have such a huge impact on how much (or little) the unibody flexes... but, they're there nonetheless - by design - for a reason. So, I gotta agree with the popular opinion of not driving without them.

Nothing to do with this but I have seen Toyota add a tiny foot long piece of metal to get the car to pass crash tests. They put it exactly where the crash is going to happen in the government testing. If you get hit a little either way of that band aid it will be bad. Little things make big differences in bodies. I also worked with BMW and they would add little band aid to cure crash test and durability issues. I am sure they all do.

David

As most of us 71-73 owners know Ford put a steel protection beam in the doors of our cars and from what I've read it made a big difference in side impact testing. A little extra steel can make a big difference.

Years ago I knew a guy who raced a 72 HO, but he eanted it to look as stock as possible even though he modified the snot out of it. Kinda' like a F.A.S.T.-qualified car before there actually was such a specification.

Anyway, he fabricated a single piece of rigid tubing from shock-tower to the firewall, and then back to the opposite side shock-tower. This single piece tieing all three points together was much more supportive and rigid than the two individual braces bolted on seperately at each side. He then put the stock braces back in place to somewhat obscure the modification. If you weren't looking for it you would probably never have seen it. He said it made a very dramatic improvement in handling and front-end flex.

I once took my driver side brace off to facilitate changing the back spark plug. Had to jack it up from the torque box ( as mentioned above) to get it to line up to reinstall the brace.

Thanks for all the info guys, very helpful. I will have it tweaked as soon as possible. I'm really happy that the only option isn't to replace the whole subframe

Hi everyone, I recently discovered that my 71 Grande has suffered from a collision at some point in its life. I found this out when I went to install my stock shock tower braces and the passenger side would not fall into place. The driver side will go in just fine. I took a close look underneath the car and found further evidence of a wreck in the form of warped and mangled metal and non-factory welds.

I'm not sure if it was a bad idea or not, but I took my car for a quick test drive after I finished with my T5 swap.I expected the car to drive odd, but it seemed to drive straight down the road. I didn't have either of the shock tower braces installed. Is driving without them installed dangerous to handling or the condition of the car? I'm guessing it causes some flex, but is it permanent? Also, can you have a unibody car straightened on a frame straightening machine or am I going to need to replace the subframe all together?

Click to expand...

This is a no no for sure. The unibody construction flexes for sure and with rust eating away in critical areas it gets even weaker. I never start to work on a car without taking it to a frame shop and having it adjusted. Every car will need pulling in some way. I have attached a scan of the Volume 4 body Ford manual that has the dimensions to the "Tooling Holes" and there is one called the M.C.H. Master Control Hole that is what everything on the car is checked from. When the body is welded in the factory they used these holes to align the panels in the weld fixtures. Yes you can align the front wheels even with a twisted frame and the car will drive ok. But you might have fenders, hoods, doors, trunks and convertible tops that do not align properly.

You can jack one of these cars up incorrectly and bend the body. Windshields have been know to crack when jacking up the car incorrectly. A frame shop with new equipment will use lasers to verify and correct the dimensions. If they have the old they will hang gages and measure the dimensions. Do it right and you will have no regrets don't and you might have more issues down the road. I cannot get the file to load it is a scan I might have to do a photo will do tomorrow.

David

Click to expand...

David,

That's interesting documentation you posted here, not sure easy to find.

Just for my information, those drawings are still good for my '73 Grandé?

(In case I need for the future).

Thanks,

Manu

Hi everyone, I recently discovered that my 71 Grande has suffered from a collision at some point in its life. I found this out when I went to install my stock shock tower braces and the passenger side would not fall into place. The driver side will go in just fine. I took a close look underneath the car and found further evidence of a wreck in the form of warped and mangled metal and non-factory welds.

I'm not sure if it was a bad idea or not, but I took my car for a quick test drive after I finished with my T5 swap.I expected the car to drive odd, but it seemed to drive straight down the road. I didn't have either of the shock tower braces installed. Is driving without them installed dangerous to handling or the condition of the car? I'm guessing it causes some flex, but is it permanent? Also, can you have a unibody car straightened on a frame straightening machine or am I going to need to replace the subframe all together?

Click to expand...

This is a no no for sure. The unibody construction flexes for sure and with rust eating away in critical areas it gets even weaker. I never start to work on a car without taking it to a frame shop and having it adjusted. Every car will need pulling in some way. I have attached a scan of the Volume 4 body Ford manual that has the dimensions to the "Tooling Holes" and there is one called the M.C.H. Master Control Hole that is what everything on the car is checked from. When the body is welded in the factory they used these holes to align the panels in the weld fixtures. Yes you can align the front wheels even with a twisted frame and the car will drive ok. But you might have fenders, hoods, doors, trunks and convertible tops that do not align properly.

You can jack one of these cars up incorrectly and bend the body. Windshields have been know to crack when jacking up the car incorrectly. A frame shop with new equipment will use lasers to verify and correct the dimensions. If they have the old they will hang gages and measure the dimensions. Do it right and you will have no regrets don't and you might have more issues down the road. I cannot get the file to load it is a scan I might have to do a photo will do tomorrow.

David

Click to expand...

David,

That's interesting documentation you posted here, not sure easy to find.

Just for my information, those drawings are still good for my '73 Grandé?

(In case I need for the future).

Thanks,

Manu

Click to expand...

Yes the drawings work for any 73. You can buy copies of the Ford Car Shop Manuals off eBay. They give every detail about how to work on your car and have all the specifications for everything in them. There are some differences between 71, 72, 73 so you need the manuals for your year model. You can get them on DVD I think. I have a set for 72 and 73 the two years I own. The manuals do not just cover Mustang but all models of Ford for that year.

76 degrees yesterday and snow maybe today??? 62 now 21 tonight???

David

The tower braces are an important part of the structure. Driving around the block probably feels the same. once you hit some bumps, go around a corner hard, or hit some train tracks it won't feel so great. Also, it could potentially damage the structure. By modern standards, all the older cars are pretty flimsy.