Technical Model T rear spring in a ModelA

I was initially going to try and reverse the eyes on a model A rear spring. After doing the front spring I no longer had the strength or will to attempt it. I know Millworks makes a really nice rear spring but by the time it would get here the cost would be well above $1000.00 Canadian .
I already had a Speedway reverse eye T spring and wondered how I could make it work. People talk about how the T spring has a different radius than an A spring. Also the T spring pack is a little shorter and needs a spacer to be able to clamp it properly.
I marked out the A radius on the top of a piece of maple and the T radius underneath , then tried the fit. It looked like it was going to work! Truth be known , I think the maple block would have worked on it's own .....for a while anyway. I wanted a more permanent solution so I rammed the wood spacer into some casting sand and poured some hot beer cans into the space left behind. The spacer turned out pretty good! I drilled it and turned a spud to locate it in the cross member and pressed it in place.
It looks like it will work just fine once I get the rear end in place and the spring mounts fabbed and welded.

 

To make up for a thinner spring pack on my Model A with a T rear spring, I just cut and tacked some spacers to the top of the clamp bars to reach up into the crossmember to secure the spring. I wouldn't have wanted to loose the drop I was getting by putting a spacer on the top. Seems to be working just fine.

But, it appears you did a nice job casting your spacer and are pleased with the result.

Lynn

 

What are you holding up with that spring? Stock springs have a lot more leaves. Like 8 or 9.

 

It's going in my RPU....too light maybe?

 

I had a T spring in my A pick up and didn't like it. I ended up with a Posies reverse eye spring. Rides as good as it can for a long obsolete suspension design.

 

You need a guy with an RPU to tell you how many leaves it takes. If you are unsure and might want to adjust later, I’d start with a spring with many and remove to taste. The shape of A and T springs prevents sourcing extra leaves from another manufacturer and hoping they fit. I’m pretty sure the Speedway spring is their own design, so Ford leaves might not fit tight.

 

Speedway T spring? Not a T spring. I ran one in the Chari-T. It was about right in a 2100# car but narrower than a stock T spring. I forget what I had to set the perch centers at, but it was pretty narrow.

 

Medium Arch Transverse Rear Leaf Spring, Reverse Eye, 38 Inch (speedwaymotors.com)
If this the T spring you have from Speedway, it isn't the same as a T.

 

I havent set the perch mounts yet, I'll try and find a stock T spring and measure that.

 

I went back to my build thread. I ended up at 42 1/2"

 

Looks like I ended up at 42 1/2"

 

Thanks man!
I appreciate the info.