I'm looking for the width of a 1940 Ford rear spring, I've searched google, the hamb, here and even on some parts websites and cannot come up with the answers needed. I bought what I was told to be a 1940 rear spring it measures 39 1/2 from eye to eye...everything I've read so far is saying 48" for a 40 rear spring can someone help me out thanks Stanley
Spring Width
- Thread starter Stan Lee
- Start date
37 Coupe
Well-known member
I have a very nice Genuine Ford 10 leaf rear spring which is correct for 39 convertible coupe and 1940 Ford coupe it measures 40 1/2 " eye to eye,also have the same in a 9 leaf rear from a 23,000 mile car both are Ford not aftermarket and being rear springs they are the correct 2 1/4" width leaves with tapered ends.
Stanley,
That sounds closer to right for the front, had all those dimensions recorded once, now gone. Previous research indicated with shackles installed, the spring should be about 2" short, used spring may be less. That much pre-load was designed in, installed the shackles will be straight and the car weight will make them at about a 45 degree angle. Just went out & measured some axles. Shackles I am using are old stock replacement stuff 1 3/8" center to center.untouched 40 axles had 2" center bolt spread.
Could the aftermarket have offered shorter replacement sets to compensate for spring deteriation ? Another can of worms.
Bottom line, dim. of the spring should be about 6" total shorter than the centers of the rearend. My centers in back prewar are 48" on the rearend mount holes, minus 4" for the shackles, 2" for pre-load, 42" ideal rear spring center on rear.
My front wishbone, '37 & '40 measures 43" at the spring mount center, so I believe the front would be 38" with 2" shackles, 39 with 1 1/2" shackles. Then, maybe the pre-load I was quoted is excessive?
If not pre-loaded, that is use a 48" spring with shackles straight down, side sway, then would need a panhard and other uncool problems IMO.
That sounds closer to right for the front, had all those dimensions recorded once, now gone. Previous research indicated with shackles installed, the spring should be about 2" short, used spring may be less. That much pre-load was designed in, installed the shackles will be straight and the car weight will make them at about a 45 degree angle. Just went out & measured some axles. Shackles I am using are old stock replacement stuff 1 3/8" center to center.untouched 40 axles had 2" center bolt spread.
Could the aftermarket have offered shorter replacement sets to compensate for spring deteriation ? Another can of worms.
Bottom line, dim. of the spring should be about 6" total shorter than the centers of the rearend. My centers in back prewar are 48" on the rearend mount holes, minus 4" for the shackles, 2" for pre-load, 42" ideal rear spring center on rear.
My front wishbone, '37 & '40 measures 43" at the spring mount center, so I believe the front would be 38" with 2" shackles, 39 with 1 1/2" shackles. Then, maybe the pre-load I was quoted is excessive?
If not pre-loaded, that is use a 48" spring with shackles straight down, side sway, then would need a panhard and other uncool problems IMO.
this is what i kept coming up with that it was a front spring and in fact not a rear spring...guess i need to look for another spring thanks for the info guys
OLD...BILL
Well-known member
Lee: I just measured my rear spring, out on the bench, fresh cleaned, lubed, and ready to go back in ( NOTE; 39 FORDOR ) 40 inch eye to eye, and I count 11 leaves, all with tapered ends. Car is all original, from super dry south west Arizona , no rust ever..... OLD....BILL
well mines definitely not a 39-40 rear spring...it has 6 leaves and is 39 eye to eye...guess i made a bad buy
oh well maybe i can figure what its from and sell ithow many leaves does your bring have...because im pretty much set that this is the front spring from a 40
I might be a dum **** but 40 years ago a spring guy told me and showed me that you measure a spring along its main leaf surface from the center bolt to the center of the eye and take that times 2. When I measure a stock 40 Ford rear spring I have I get 48 inchs. Measuring straight across eye to eye can be all over the place depending on the number of leafs, arch or lack of.
Krylon32, Your method is the only logical way to do it. Just measuring the span when unloaded is sure inaccurate.
Here is a thought.
How about starting a list of springs and giving both the measurement along the main leaf, the relaxed span, and the leaf width?
I have a stack of springs and don't know the applicatins for them.
I have some covered springs that I think are 46-48 fronts. Also 32 front springs, 40 fronts, and some unknown rears.
Here is a thought.
How about starting a list of springs and giving both the measurement along the main leaf, the relaxed span, and the leaf width?
I have a stack of springs and don't know the applicatins for them.
I have some covered springs that I think are 46-48 fronts. Also 32 front springs, 40 fronts, and some unknown rears.
