Building up leaf springs

John Burne

John Burne

Member
I took the front leaf springs out today. I ended up snapping off a couple of the u-bolts. After I had the old springs out and compared them to the replacement springs, I noticed the arc was about the same, but the old springs had 8 layers and the new had only 7. I'm thinking of getting new, longer center bolts and using the second or longest spring from the older ones to add to the replacements. Anything wrong with this plan? - John
 
Last edited:
Fair question. I should have explained better. The old springs were sagged out to the point where they were bending into the negative. I had hoped when I laid them next to the newer ones that there would be a noticable difference in the arc. There was none. After then noticing the replacement springs had one less layer of springs, I got to thinking, (probably over thinking), that these would also sag out. Update: I just looked up Front Spring Capacity in my 1955 Manual. It shows F100s with standard 8 leaves at 950 with an optional 7 leaves at 1050. These show the same width and same bushing id. The F-250 shows a standard 7 leaves at 1050 and an optional 7 leaves at 1200. - John
 
Last edited:
The difference in spring rates is probably due to the material used in the spring, the way they heat treat or manufacture them. Possible thickness difference???

I don't like to do things twice either but if you cannot ask the supplier of the spring what the rates are, testing them on the truck is probably the only way to go.

Since the old springs are in poor condition, I suggest not using them until you find out the newer springs won't do the job.

I just replaced the rear springs on my 64 Fairlane. I compared the old ones to the new ones and the arc was the same. But a big difference on how the car sat.
 
Paul,

Long day under the truck. I tried the replacement set and they seemed weak. Pulled them out and then took all four sets apart, went and got new center bolts, and reassembled with the added longer spring. I then got the new and improved sets in place and they didn't look a heck of a lot better. They look flat to me, although I did notice the pictures of the front springs in the manual look fairly flat as well. I still need to figure out a good set of front shocks. - John - Update, The springs worked better than I thought they would. Napa has only one cheap set of shocks that will fit. The techs at KYB say they've got nothing. Oh well, I'll enjoy the improved springs and not worry about it.
 
Last edited:
Google KYB. They have a web site and may have a set for an early truck. Also try NAPA, Advanced Auto.
 
You must log in or register to reply here.
Back
Top