To begin, on many 40 year old trailers, the spring/axle setup has been modified or replaced. For example, many replace the drop axle
with a straight axle
. Many replace the springs.
Anyway here is my 1979 Boler
1700 setup (EDITED):
- its a drop axle
so the trailer can't be raised 4-5" by simply flipping the axle over and moving it from above the leaf springs to below the leaf springs
- instead [previous owner actually did this] the drop axle can be re-located from above to below the leaf springs, and the spring perches moved (and re-welded) from above the axle to below the axle
- the resulting height was STILL pretty low (coupler height about 13 inches) because the springs were worn out
I recently had the leaf springs replaced, and this raised the trailer 4 to 5 inches!!
If you have the same size leaf springs (3-leaf, 23 1/8 inches from bolt center to bolt center) and they need replacing, I would recommend replacing with UNIVERSAL 23.13" Double Eye Leaf Spring (3 leaves / 1750 lb.) #UNA-216 or equivalent.
If your axle has already been moved below the springs or replaced with a straight axle, and if the leaf springs have already been replaced, another option is to add a 2-4" spacer between each spring set and the axle [using longer u bolts].