Length of Rear Spring
- Thread starter Cartravel
- Start date
I did a search a few days ago for the same issue. I found the attached diagram, obviously old (look at the price of the rear spring!) but still should be OK. Note that there were three versions of the 10-leaf rear spring, I'm not sure how to tell them apart. Or that it's terribly critical, I've only seen one 10-leaf rear spring listed for replacement.
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bruceincam
Senior Member
I show the free length at 38 7/8" to 39" for a Tudor and Fordor.
Joe K
Well-known member
The differences are in the make-up (thicknesses) of the leaves. Each spring variant has correspondingly "varied" leaves.
Ford was rather ingenious in the way he made "adjustments" in a manner which utilized existing production. I haven't checked specifically but I imagine that at least a couple possibly more of the 8 leaf spring "leaves" can be found in the 10 leaf(s)
The last time we discussed this someone made the statement that leaf-wise, Ford only produced 17 different leaf patterns and from these 17 he produced five springs for varying weights of cars.
Marco had a color coded "guide" to the spring leaves and their uses on the A through E spring production. There were only three different BWG thicknesses represented with a fourth which wasn't actually a spring but a "spacer."
Tom Wesenberg blessed us with the spring chart some time before his passing. Seen at https://fordbarn.com/forum/showthread.php?t=62383
Joe K
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Joe, thanks for referring to this post. Very informative. I had seen the Tahtaras chart but had no information on which 10-leaf spring (A, D or E) went to which body style.
Looking at the catalog cut I found, is there any way to relate the various 10-leaf measurements to assign them A, D or E? It almost looks like they may be top to bottom A (10-leaf), B (8-leaf), C (7-leaf), then maybe D (10-leaf) and E (10-leaf)?
BTW, the posted chart is kind of difficult to read. Anyone wants a higher-resolution of that, please PM me with an email address and I'll be happy to send it along.
Looking at the catalog cut I found, is there any way to relate the various 10-leaf measurements to assign them A, D or E? It almost looks like they may be top to bottom A (10-leaf), B (8-leaf), C (7-leaf), then maybe D (10-leaf) and E (10-leaf)?
BTW, the posted chart is kind of difficult to read. Anyone wants a higher-resolution of that, please PM me with an email address and I'll be happy to send it along.
Joe K
Well-known member
I have done this but the way to do it is to "measure" the thickness of the various numbered leaves.
Not easy to do when the spring is assembled although technically you could use a depth micrometer and measure each of the steps that differentiate the different leaves.
Disassembled its standard micrometer fare.
The Marco/Tom drawing shows the spring leaves "hollowed" somehow - but I have not found the Ford leaves nearly so hollow if at all. There is a "tolerance band" for BWG which is shown on the Ford drawings and on this chart and generally a spring leaf is "a thickness" within this range and doesn't vary any across its thickness as shown on the drawing.
BWG charts don't normally show a tolerance - just a single thickness.
The other way to do this might be the "elevation drawing" for the spring. Not only thickness of the leaves is shown, but also their lengths and even the "caul radius" to which the leaves are bent (the "pre-tension" of the spring before assembly) The lengths might vary and you could "correlate" these lengths against what you have.
Of course you'll need the drawings. Some of these are out there and respondents might be able to attach.
Joe K
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