roadtripper
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Post by roadtripper on Nov 10, 2019 19:06:51 GMT -8
I’m changing the leaf springs on my 62. Pretty straight forward except for finding an exact match. My old springs measure 26 1/2 “ center to center. The hanger distance is about the same. The springs they gave me down at the rv shop are 25 3/4”, and when mounted they pull the shackle in towards the axel. Under load the shackle is down...90 degrees to frame. This seems wrong. Reading around it seem like about 45 degrees angled back under load is about right. Another site, etrailer, said rule of thumb is spring about 1/2” longer than pin to pin deminsion. I see 27” shackles available so that’s what I’m thinking to try.
I have a fairly new dexter axel 3500 lbs rate. Springs rated at 1750 each seems proper. My trailer is max 3k totally loaded water and all.. usually a couple hundred less. Any reason to go heavier?
What do you think on length and pound rating?
There is a surprising amount of on line discussion on shackle angle out there, but mostly with guys building hot rods and rock crawlers.
thanks for any input.
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Post by bigbill on Nov 11, 2019 6:54:30 GMT -8
A shackle has to be long enough to keep from flipping backwards if the trailer becomes airborn for some reason and it also has to be of a length that allows spring to bottom out on a hard bump without binding. These are the most important things, angle is not that important.
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Post by bigbill on Nov 11, 2019 14:38:49 GMT -8
Also remember the shackle length and position controls to things other than holding axle under trailer and allowing the springs to flex. They control ride height and axle angle. Most axles have a slight amount of toe built in, if so the spring pad should be parallel to the ground or at least close when the loaded trailer is sitting on the ground. You mentioned shorter springs but is the arch the same or different? My next thought is if you go with a heavier spring are they longer? I like a bit more load rating between rated load and actual load. As springs settle in they will normally loose some capacity.
These don't give you an exact answer just some food for thought.
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roadtripper
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Post by roadtripper on Nov 11, 2019 20:12:09 GMT -8
Thanks Bill for the input. The springs I got are a little shorter than original however the original have undoubtedly flattened or grown a bit in the last 60 years. I spoke with 2 more mechanics in town I know today and they both think I should go with the new ones I got, so that’s what I’m going to do. The arch on the new is close to he old, but hopefully the new will give the axel to frame clearance I need as they are fresh and will settle in as you say to the length of the original, but still stand taller. I hope to get it all back together next weekend, including the new tires I got today.....205/75 8 ply rated radial by Carlisle. Also doing some new belly insulation and board. Hopefully a test run in the next couple weeks.
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ruderunner
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Post by ruderunner on Nov 16, 2019 3:33:08 GMT -8
One thing to keep in mind is that leaf springs are arched. You can't get an accurate eye to eye measurement by running your tape in a straight line.
You need to follow the arch of the main leaf.
If your old springs have less arch than the new ones, you might be closer than you think on the eye to eye measurement.
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roadtripper
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Post by roadtripper on Nov 17, 2019 6:53:09 GMT -8
Thanks, and your right. Not too much difference. I’m gonna go with them. In the meantime, since I’m up on blocks I’m doing some new insulation work under there .
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