Spring hanger torn off...probably my fault!

[working on it]

After working two 70-hour weeks, motivated to do something I wanted to do for a change (and the extra cash to do it with!), I thought this was the perfect weekend to start my "axle replacement" final push, before my next outing on April 25 (I've been planning either strengthening it, or replacing it entirely with a heavier-duty version). As usual, I researched alternatives, and shopped local sources for possibilities before jumping in. However, after finding a suitable replacement axle- I had finally decided not to try to sleeve it, since I'm a beginner welder. I decided on a Carry-on 2k axle w/hubs at Tractor Supply. So, in last-minute double-check, before going down to purchase it, I went to the garage for some FINAL, ACCURATE measurements. I crawled under, and scraped away some undercoating/paint from the axle tube -it is only 1.25" square, as I feared, very spindly for a 1515lb trailer- and I confirmed that the TSC axle would fit. Then I went inside to retrieve my phone/camera to take a "before" picture, prior to the swap. When I returned from the house, I came face to face with this, somehow overlooked before:

hanger ripped loose.jpg (66.38 KiB) Viewed 2384 times

weld failed.jpg (75.97 KiB) Viewed 2384 times

I may have only found this break (the hanger welded to the frame, holding the right rear shackle) because I had re-levelled the trailer a few minutes before, shifting the weight. I had not seen it in the 5 months since I had camped in it, though I had been under it several times since then, including 20 minutes immediately prior. The torn piece has shiny, un-rusted edges, so I must've had it break just then. Fortunate that it happened in the garage! I'll never know if it was caused by my ill-advised "axle safety" attachments, that probably forced the metal fatigue at that location (by reducing the ability of the springs to flex and absorb energy?, since I clamped the leaves tightly together-good for dragracing launches, not so good for trailer springs), or it was inevitable with the oversized load on an undersized, old, basic frame. I now have to patch, and reinforce, the torn spot, remove the other (suspectedly weakened) hangers, and start over. The basic frame is made of thinner material than my additional pieces (3"square tube tongue, 12" front and 24" rear platforms of rectangular tubing), so I'll want to weld and bolt-on new hangers. Additional plan: the original frame tubing will have a 3 foot length of 1/4" angle welded/bolted to the inside bottom of the frame. After having balanced my trailer to make it work as it is,

dimensions-balance.png (57.14 KiB) Viewed 2384 times

I plan on put installing the new axle in the same location, but with new-longer- springs, so I'll get the whole axle package as a kit. I do have a question, though: for my 1515 lb (current loaded weight) or maybe 1600 lb trailer (after new axle, springs, reinforcement), would I be better off getting a 3500 lb axle (might as well get heavier-duty) with 1750-2000 lb springs, or get even heavier rated springs? And did I mention shock absorbers to come?

[48Rob]

It looks like there is just a sleeve welded to the frame to carry the shackles.
Were it mine, I would use shackle hangers designed for the purpose, which will spread the load.
Is the spring hanger attached the same way? I would be real worried about all the attachment points on a trailer built like that, including the tongue...
You might consider building a "sub" frame, that is, weld the hangers to a suitable piece of angle and then weld or bolt it to the frame.

Rob

[Redneck Teepee]

It looks like there is just a sleeve welded to the frame to carry the shackles.
Were it mine, I would use shackle hangers designed for the purpose, which will spread the load.
Is the spring hanger attached the same way? I would be real worried about all the attachment points on a trailer built like that, including the tongue...
You might consider building a "sub" frame, that is, weld the hangers to a suitable piece of angle and then weld or bolt it to the frame.

Rob

What Rob said ^^^^ be sure and stitch weld it as it will be less likely to re-crack again.

[working on it]

(A)It looks like there is just a sleeve welded to the frame to carry the shackles.
Were it mine, I would use shackle hangers designed for the purpose, which will spread the load.
Is the spring hanger attached the same way? (B)I would be real worried about all the attachment points on a trailer built like that, including the tongue...
(C) You might consider building a "sub" frame, that is, weld the hangers to a suitable piece of angle and then weld or bolt it to the frame.
Rob

Rob-(A)Yes,it is just a 1/4" thick sleeve, just welded to the original frame tubing (with no further support or bracing)...look at the picture in extreme close-up, and you'll see how thin walled it is, and minor interior surface rust (it just pulled apart, not rusted thru). I think that all the hanger mounting points are similarly weak, and untrustworthy, even if I could patch that one back in place, I would never trust any again. I am primarily a "bolt-together" aficionado, having seen far more welds fail than bolts, and usually with more costly consequences (with one notable exception: a big-block Chevy connecting rod bolt @ 7800rpm...). I remember reading about the Liberty ships' welds breaking apart in WWII; I have never fully trusted welds since I read that (yet, I want to learn welding...go figure?). (B) The hanger welds were the only ones that I ever worried about; the others were just attaching angle to rectangular tubing, and were solid (and the new metal we welded on is done so even better, and of thicker-walled stock). The tongue is an entirely new piece, of thick-walled 3" square tube, welded to three crossmembers and to a second longitudinal center beam. Really burned in, and solid. (C) After I posted last night, I formulated a plan to build such a subframe, looking much like this (except of thicker steel angle):

shackle assemby 4723_st.jpg (17.72 KiB) Viewed 2308 times

from 1/4 steel angle with hangers welded and bolted to it, then the assembly will be bolted and welded to the original frame (bolts run thru from the side as well as the bottom, and welded all around). Today, I will clean the garage bay where I have the trailer (the area is packed, not suitable for major demolition/welding/fabrication work), and put the trailer up on jackstands, and begin the disassembly work. Thanks for responding, Rob; do you think the 3500lb axle and 1750lb (each) springs I plan on getting will work OK on my heavy little trailer? and, Redneck Teepee, I'll try stitch welding as you suggest...but, given that I'm just a welding novice, I'll make more tack and spot welds beforehand (and rely on Grade 8 bolts/washers/nuts for the safety factor).

[jss06]

When I was building my frame I was worried something similar may happen to mine even though I was using a thicker wall steel for the main beams. So i Reinforced the mount points with some 1/4" angle I had lying around. This pic is with everything tacked together waiting to be welded.

[48Rob]

I did a similar setup on a trailer awhile back.
It was a large angle, in the photo the end is not visible, but it fit in the space inside the fender.

[working on it]

I did a similar setup on a trailer awhile back.
It was a large angle, in the photo the end is not visible, but it fit in the space inside the fender.

48Rob-that's what I plan on doing, except the angle-up will be on the inside, where I can weld (and bolt, of course) without having my very fugly welds show (and without having to remove the fenders, which are in the way of the 36" long angle stock). I plan on using a 3 ft (the new springs will be 25.25" long) length of 1/4" angle (or 3/16" if it would be strong enough, I'll research) with weld/bolt brackets

weld-bolt front hanger.jpg (17.09 KiB) Viewed 2265 times

like shown by jss06 attached to the piece before final attachment to the trailer. My repairs will be hidden from view, since I just know the welds will be horrendous. So, out of sight and painted black.... But, I'm going to turn up the heat to really penetrate the steel, so it might just work out. My practice plug welds aren't too shabby, so I'll utilize them too. I've just now lifted the whole trailer up on four-cornered jackstands, and I'm using the tongue and Chevelle jacks, and my stabilizers to supply extra support as well. Here goes....

[48Rob]

Something to consider if using the angle is preventing moisture, dirt, etc, from being trapped between the angle and frame where it can, and probably will rot one or both...unseen until the frame breaks or collapses.
I used moisture cure polyurethane glue/sealant to be sure that didn't happen.

If you are worried your welds will look bad, why not do all the welding up on a bench where you can do a good job, then bolt the assembly to the trailer?
I don't presume to teach anyone to weld as I am only a handyman, but most people can produce decent welds on a horizontal surface, up close where you can see well.
A couple $5 pieces of bar or scrap the same thickness as your work will give you a chance to practice and determine the right heat, speed, and angle before moving directly over to the job at hand.

Rob

[working on it]

Good points. I will heed your advice on all. I just removed the axle from the trailer, and found three things: both springs were not frozen solid by my safety straps (so my experimental piece did not cause the failure), the other three hanger-to-frame mounts were in perfect condition,

welds in perfect shape.jpg (71.41 KiB) Viewed 2241 times

and finally...the "cause celebre": the broken off hanger's bolts/nuts had been drastically over-tightened on both the frame side and the spring side (my 240 ft-lbs impact won't break it loose!; I had to use a pipe over a breaker bar).

locked together.jpg (81.58 KiB) Viewed 2241 times

I don't know how or when it was tightened, or by whom, as it was done a long time ago in a shop far away (either I or one of my friends, all usually skilled with impacts and torque wrenches, made a mistake!). The hanger pulled the thin frame metal apart, as it was weaker than the hanger straps/spring/frame bracket. Nothing else was damaged. I could probably repair that piece, and re-use everything, but will go ahead and upgrade (since I want/need to). I re-measured everything, and now can order the upgraded parts: 62" hubface - 49" spring center 3500lb axle, 25.25" double eyed 1.75"wide springs, hanger brackets, and the angle steel. All my bushings, hanger straps, nuts/bolts are new (150 total miles). Looks like I have a spare axle, springs, new hubs, and 1.25" wheel adapters for a future project. Also, I found that the square tube axle wasn't bent, but was cambered and mounted upside down (I never took it apart to see before). My error.

[48Rob]

I do have a question, though: for my 1515 lb (current loaded weight) or maybe 1600 lb trailer (after new axle, springs, reinforcement), would I be better off getting a 3500 lb axle (might as well get heavier-duty) with 1750-2000 lb springs, or get even heavier rated springs? And did I mention shock absorbers to come?

400 pounds under the rated load isn't bad for ride comfort (spring wise) but it is getting close for dynamic load on the axle.
I'm not an engineer, but 1.5-2 times the static load (and common sense) says you would be less likely to bend the axle hitting a big pothole, etc, if it were rated for 3500 pounds.

2000# Springs sound about right for a 1600# load, though I believe I'd opt for the 3500 pound package, and then remove a leaf to end up with springs rated for 2500 pounds and if I found the ride to be too harsh, go back down to the 2000 pound springs.
Shocks are generally used to control spring rebound, if you get your trailer weight versus spring rate in the right ballpark, you will likely not need them.

Rob

[working on it]

I've got another question (or two) for you Rob; I saw a picture of your hanger assembly while researching on the web

ry=400.jpg (22.73 KiB) Viewed 2137 times

That's exactly what I want to make. I was planning to use 1/4" thick angle, but it appears that yours was thinner gauge steel. ???? If thinner, what did you use, and did it distort/warp in use, or stay put? I intend to use hanger brackets of 1/4", and shackles of 1/4", so 1/4" angle to match would make it darn near bulletproof. A three foot long welded and bolted hanger assembly, then perimeter welded and bolted thru frame (in 6 places; 2 straddling each hanger and 2 more in the center) with Grade 8 hardware, with either Loctite PL Premium or OSI Quad sealant (I have extra tubes of each) in between angle and rectangular tube frame (to keep water out). Would either sealant suffice? A last precaution against water: undercoating over all, after the sealant and paint cured. I think I've settled on getting two 1250lb springs (2500lb capacity) to go with the 3500lb axle. Knowing my propensity to overload, overbuild, and add-on, I can see this trailer eventually being 2000lbs...I'll need the reserve capacity of 2500lbs.

[KCStudly]

Your frame appears to be extremely thin material. I would avoid riddling it with a bunch of bolt holes. Also, thin material in an awkward overhead situation (such as under you trailer) using a stick welder is about the biggest challenge that a novice welder will encounter.

... I'm going to turn up the heat to really penetrate the steel...

I foresee severe burn thru in your future. The correct heat setting is dependent on the metal thickness/size of bead, size of the electrode (which needs to be selected based on the former) and sometimes the weld configuration (fillets like a little more heat to get down in the corner, whereas flat butts want a little less). You can usually dial in a little more heat for tacks to get in and out quicker, but your biggest problem is going to be not burning away the steel and punching holes. I would start on the cold side and creep up on the best heat setting. The longer each individual weld, the greater your chances of burning thru, or having the puddle roll out into your lap (so to speak).

Knowing the cause of the failure and correcting the overtightened shackle, I would be tempted to just weld the shackle mount back into the hole that it came from and let well enough alone.

[48Rob]

I've got another question (or two) for you Rob;

The angle was 1/4".
I did not weld the assembly to the trailer, I cleaned everything very well and used PL to glue it on, and also used 3 grade 8 bolts.

I think welding to your thin frame is best left to a pro...
KC knows more than I do, but just looking at the torn metal, the small area of weld, and the fact that the weight, because of the small contact patch, is not spread out, I would at minimum, want a standard shackle hanger.
The attachment method; using a small sleeve looks suitable for a backyard cart to pull behind a lawn mower, not a 1500 pound trailer running 75 mph down the highway (my opinion).

Rob

[working on it]

Ok. I get the drift of this. I will just take my time and work on the attachment sub-assembly until it looks good. Then I'll bring it to work, and let an experienced welder ok it, then just bolt it in place with side and vertical bolts both. I didn't really want to weld on the .125 frame metal, but would've tried....

[KCStudly]

Looks thinner in the pic's.