Rear Spring Centre bolt

BobbyG

BobbyG

Senior Member
Reading through the recen thread by Ol Jenny, I have a couple of questions re that bolt in the rear spring.

I have my spring and axle off the car right now (doing a rebuild on rear end)

Does that bolt have to have a square top on it - my bolt has a weld on the nut - presumably to prevent it coming undone - I intend to split the spring pack and I doubt that the nut and bolt is going to be re usable, can I use a regular hi grade nut and bolt?

If my springs are Ok - what is the best I can do for them - wire brush - paint grease between the leaves ?

Bob
 
The square head fits into a square hole in the frame. I suppose it helps to center the spring during install, but I am unsure if it serves any other purpose.

I wire brushed, and installed poly-sliders, black Rustolium the Spring pack prior to install.
 
BobbyG said:
Reading through the recen thread by Ol Jenny, I have a couple of questions re that bolt in the rear spring.

I have my spring and axle off the car right now (doing a rebuild on rear end)

Does that bolt have to have a square top on it - my bolt has a weld on the nut - presumably to prevent it coming undone - I intend to split the spring pack and I doubt that the nut and bolt is going to be re usable, can I use a regular hi grade nut and bolt?

If my springs are Ok - what is the best I can do for them - wire brush - paint grease between the leaves ?

Bob
Click to expand...

it will be tough to reuse your bolt unless your able to compress the spring leafs together and catch the nut. when unbolting the leaf pack there is quite a bit of pressure that the bolt holds together. the replacement bolt sold by the jobbers is a lot longer so one can draw up the pack tightly and then cut off the end of the bolt after the nut.. its a good idea to take them apart clean and lube the leafs and reinstall. my personal opinion is if its an old spring and its off in my hand i am replacing it ( i also take apart the new springs and grease). the bolt's square head fits into the frame hole which centers the spring properly for assembly and even after its clamped with the u-bolts prevents shifting.
 
Thanks chaps - I will maybe machine up a new bolt to give it a square head to locate in the crossmember.

Bob
 
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6 leaves on rear of 28 coupe - is that about right ?

Bob
 
For mine, I aquired a longer grade 8 (Lots of radial lines one the head)bolt and cut it off to length after the spring was compressed.I just ground two of the points off the head of the head so it would fit in the hole. As I said in my profile, "My A", I used a large C clamp for insurance against failure of the bolt. However, I have a Town Sedan that uses a 10 leaf spring. That spring is scary.
Terry




BobbyG said:
Thanks chaps - I will maybe machine up a new bolt to give it a square head to locate in the crossmember.

Bob
Click to expand...
 
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According to the "Springs Used Under Model A and AA Chasses" chart on page 22 of Volume 1 of 'How To Restore Your Model A', the correct spring for the 45-A, -B and -C coupe is the 8-leaf A-5560-B assembly.

This chart is described as originally published in the July-August 1931 Ford Service Bulletin.
 
The compressed rear sping pack has a lot of pressure, so beware of using cheap C clamps that can break.

I always sandblast the leaves, grind the wear pockets, then paint and use grease and a sprinkle of graphite between the leaves.
 
All the vendors sell the correct square head bolt. It comes extra long so you can get the nut started. Then as you tighten the nut, it compresses the springs. Once your done, there's a bunch of extra thread that you just cut off. I like to leave about a quarter inch of the thread showing, then beat it with a hammer to mess the threads up so the nut can't work it's way loose. I powder coat my springs. Which ever way you go, remember the springs are not supposed tone high gloss black. They were almost flat black like the frame.
 
Thanks everyone - lots of great info there - I will replace the bolt with a new one as suggested and I will of course give that spring the necessary 'respect'

Thanks
 
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