1971 Fastback Trunk torsion springs source?

[Wolf]

Hi All:
Hope someone can help me find a torsion spring for the trunk lid on my 1971 Mach 1. It does have a wing so I would love to find a pair of thicker springs but will settle for the thinner ones if that is all I can find. One of my springs just snapped overnight while the car was just sitting. Any help would be appreciated.
Thank you

 

[TexasBoss]

Yes, the torsion rods for the trunk with rear wing are thicker as seen in this pic. I would recommend Mike from Motorcity Mustangs or Don at Ohio Mustang Supply to check their inventory for a used pair. Also, find a "how to" on this site to install. Requires a special tool or risk ripping your fingers when a rod lets go.

 

[machattack]

Yes, the torsion rods for the trunk with rear wing are thicker as seen in this pic. I would recommend Mike from Motorcity Mustangs or Don at Ohio Mustang Supply to check their inventory for a used pair. Also, find a "how to" on this site to install. Requires a special tool or risk ripping your fingers when a rod lets go.

View attachment 87191

I have a spoiler on my deck lid. The extra weight is just a bit to much for the lid to stay open. Its set on its highest load limit. So, maybe the bigger diameter would work better if you have a spoiler? Be careful as that spring will mess you up when it comes off.
For safety I installed a lock down shaft collar on the end of the spring to stop it from sliding out of the grove. Hasnt moved yet.

 

[roboconklin]

I have a spoiler on my deck lid. The extra weight is just a bit to much for the lid to stay open. Its set on its highest load limit. So, maybe the bigger diameter would work better if you have a spoiler? Be careful as that spring will mess you up when it comes off.
For safety I installed a lock down shaft collar on the end of the spring to stop it from sliding out of the grove. Hasnt moved yet.

NPD sells a light weight rear spoiler that looks exactly as OEM. I think you can use thinner springs. I don’t know how expensive or readily available the thicker rods are. Just another suggestion.

 

[73MustangCoupe]

I purchased the NPD spoiler. It worked out great. When I installed it, with both torsion bars, I could not get it to stay open. It had worked fine before I installed the spoiler. The torsion bars seemed to go in easy enough - not a big deal. It struck me, could they be installed incorrectly? Yup!!! I reversed them and the trunk lid pops and stays open just fine with the spoiler. So check and see if the rods might be reversed. I can make a difference.

 

[rcadd1ct]

I ditched the springs and followed Austinverts lead and fabbed up a bracket to use a gas strut.

My car is not stock so I don’t care about originality.

 

[boss49472]

Hi All:
Hope someone can help me find a torsion spring for the trunk lid on my 1971 Mach 1. It does have a wing so I would love to find a pair of thicker springs but will settle for the thinner ones if that is all I can find. One of my springs just snapped overnight while the car was just sitting. Any help would be appreciated.
Thank you

Hi All:

I've posted this response to other questions about the torsion bars. There are, in fact, two versions of the torsion bars, one made of 0.200" spring steel and one made of 0.225" nominal spring steel. The larger diameter bar is for the cars with factory rear wing. I also assume it is probably also for the large trunk lid of the convertible.

I did a lot of investigation to have new torsion bars made, and had several failed attempts at material selection and heat treating. The solution was to make the bars out of ASTM A228 "music wire" steel. Common spring steel and high chrome steels don't work as they don't have the yield strength for this application. Spring Dynamics Inc. in Almont Michigan made them for me from 0.236" round stock they run regularly for a Ford OEM application. I made the installation tool below from 0.125" thick steel stock and a 0.250" hole drilled in the bolt and at the tip. My car has the sport deck rear seat so its a little tight getting the tool in place.
Spring Dynamics made a couple of sets for me and several sets for Blue Oval Car barn in Mineral Wells Texas.

 

[rio1856]

Hi All:

I've posted this response to other questions about the torsion bars. There are, in fact, two versions of the torsion bars, one made of 0.200" spring steel and one made of 0.225" nominal spring steel. The larger diameter bar is for the cars with factory rear wing. I also assume it is probably also for the large trunk lid of the convertible.

I did a lot of investigation to have new torsion bars made, and had several failed attempts at material selection and heat treating. The solution was to make the bars out of ASTM A228 "music wire" steel. Common spring steel and high chrome steels don't work as they don't have the yield strength for this application. Spring Dynamics Inc. in Almont Michigan made them for me from 0.236" round stock they run regularly for a Ford OEM application. I made the installation tool below from 0.125" thick steel stock and a 0.250" hole drilled in the bolt and at the tip. My car has the sport deck rear seat so its a little tight getting the tool in place.
Spring Dynamics made a couple of sets for me and several sets for Blue Oval Car barn in Mineral Wells Texas.

Just ordered a set of torsion rods from Spring Dynamics. Eric the guy I spoke with said the pair of rods will ship out Tuesday next week. Thanks for the lead on getting these boss49472 much appreciated. Now my trunk lid with the spoiler will stay open.