Leaf Spring "Wrap" Orientation on Tandem Axle Trailer- Need Advice - Page 2

Originally Posted by sledge42

Bear: I ordered the PR4B
"This 4-leaf double-eye spring is 25-1/4" long x 1-3/4" wide. It is designed for use with 3,500-lb trailer axles"

haha, I just measured mine, 25 1/4" center to center(and only one wrap ; ), never been used, they came on the axle I had made but I didn't need em

I just looked EMCO JBB6 PR-4b ; )

I need a translator for all this.





Sirscrapalot - My head hurts now.

Sledge,

From what I was able to find on the 'net, I think you have a rebound clip, as what Joe suggested. Looking at Google Images of springs, a lot of them have clips on both ends. However, it seems that their use is to reduce the load on the top spring leaf when the axle rebounds after a bump compresses the spring. The clip forces the spring leaves that are clipped together absorb the rebound forces rather than just the top spring taking all the load.

I'm guessing that the reason there is only one rebound clip on trailer springs is because the unsprung weight of the trailer axle, tires and brakes is not a lot when compared to the weight of a driven axle with all its gears housings, and stuff. So only a portion of the spring leaves need to be pulled into play with just one rebound clip. A clip at each end would double the amount of rebound resistance, which maybe is not required for a light trailer axle.

I would further guess that the rebound forces that the spring has to resist will be best controlled at the spring hanger that has the least linkages to the trailer frame, which is the ends of the spring that are NOT coupled to the frame through the equalizer link. This is because if the forces transferred through the equalizer link, there are an extra couple of bolts that can wear a little faster with the rebound forces going through them. It could be argued that this is not a huge consideration and the springs could be installed with the rebound clips in either direction.

So I am with Bear and Mechanic in suggesting that your sketch no. 4 would be the recommended spring arrangement.

Jon.

That makes perfect sense Saw, so it would be best placed nearer the solid anchor bolt

I Googled "what is the band for on a leaf pack", and etrailer.com was the first to pop up.

Maybe you got this guys brother..."Excellent question. I had to think about this one for a bit and consult another person familiar with trailer assembly."

Installation Direction of Leaf Springs Does the Band around the Spring Pack Go Forward | etrailer.com

Post #3 seems to reiterate what sawmilleng said.

Mystery leaf spring bands - and overload bumpers... - International Full Size Jeep Association

From what I can see, Bear's trailer doesn't use slipper springs.

I had an occasion to replace a axle that used slipper springs. Until then I had never seen one. Was interesting to see how it works.

Originally Posted by sledge42

Sawmill-
Without it being as in-depth as your post- those were my thoughts as well! Thanks for articulating it and digging into this for me.. and others to follow!!

Bear: That is hilarious that you have the same springs I just ordered.. what are the chances?

I appreciate all the input gents!!

It's probably just the standard spring for that size axle. They were attached to the axle when I got it, but I already had springs on the trailer, so I took em off and mounted the axle onto the trailer. They've seldom seen the light of day, and I've seldom given them a second thought. They're a bit longer than I recalled, I thought they were even smaller till I went and looked.
Not sure if I'd ever find springs the size I've got now, but they'll eventually need some attention I suppose. When I did hotshot truck parts deliveries around Nashville, there was a man had a shop there and would replace broken springs, I think he made them from stock material, cut them to size.
At least in the future we'll never need to ask em what that dam strap is for again ; )