the increase in UNSPRUNG WEIGHT(larger wheels n tires) can add to the issue created w/ the lighter springs
leaf springs work BOTH WAYS... up n down
when bounced hard the rebound of the softer spring launches the axle assembly downward
the arch of the softer spring increases thus shortening the effective length of the leaf allowing the spring to escape it's keeper
it aint rocket surgery just simple physics
this has happened to me when i had removed a couple leaves to soften a ride and i had to put those leaves back in
going from thicker to thinner springs for softening the ride is the same as removing leaves and WILL allow similar results
those slipper springs have tongues that define the location of the keeper given a specific load range
when changing from thicker to thinner leaves you need to consider relocating the keepers which may not be an option for some folk's abilities/equipment access
this is one reason i avoid slipper springs when buying/building trailers
the shackle system using 3 bolts to hold springs is for me a more reliable system
if your keepers are the welded in place units
- th.jpeg (3.22 KiB) Viewed 3336 times
AND you have welding abilities you could consider moving them fwd a bit
if the keepers are bolt in place units
- th-1.jpeg (6.85 KiB) Viewed 3336 times
all you have to do to move them is drill new holes fwd of the existing ones
while at it you should check the nylon eye bushings in the fwd end of the spring to make sure there isn't any slop there which could affect the relative length of the leaves as the arch increases/decreases
in this pic you can see the white eye bushings i'm referring to as well as what industrial/agricultural trailer manufacturers are doing to help with this issue
- th-4.jpeg (3.37 KiB) Viewed 3336 times
they use a lip on the 2nd leaf of slippers to help prevent escape
¿ have i muddied the waters enough yet ?
sw