Broken Spring Hanger - Fix

[Terrytruett]

After seeing quite a few broken hangers, and having a couple of days to play, decided to go ahead and add some strength to these supports. Funny thing, I had thought about this design and then saw it on another post as a fix from a field repair. This fix provides additional weld support on the top and stiffens vertical hanger toward the spring bolt. These hangers are extremely tall with no support. I'm surprised we do not see more breaking than we do.

This project took a full day. (I guess I could have picked a better day that wasn't over 100 degrees) Took an hour to round up all my tools and get things ready to go. I removed only one wheel at a time for safety. I do not have any small tools to clean inside of hanger but did find that if you use enough "break parts cleaner" you can pretty much wipe all the paint off and then wire brush to clean. It's gotta be clean, no cheating welding in these positions. I chose to remove the welt bolts, fearing extremely high heat to bushings not to mention the grease. I had the angle shown laying around my shop so thats what I used. Cut at 1 7/8" wide. Prep all metal, no rust, no contamination! The outside welds were no issue. The inner welds, well, there is always something in the way like breaks, axles, plumbing, camper jacks, etc.

If you have ever watched your wheels, tires, and hangers, twist and bend when making a tight turn, it is amazing these things do not all break. Now the weak point is going to be the aluminum wheels.

Hope this may help someone. Happy Trails!

[avf100]

Nice job !!

[FT4NOW]

Looks great!

Sent from my SM-G950U using Tapatalk

[Joseph143]

Did you drop the coraplast to do the welding? Thx. Joe

[WhittleBurner]

We were the field repair you read. Yours looks just as good (nice welding) as ours that was done by lipperts road techs who were absolutely great. Lippert came through big time for us.
We had a bad weld fail while we were in FL a couple years ago, and Lippert sent a road tech who replaced the hanger. But not knowing how far we drove on it broken, it must have caused the opposit side to weaken and show stress cracking that no one could see at the time. Just as a precaution they decided to add the clips to all 4 hangers after the 2nd fix a couple weeks later that was done at the TN rally.

[Terrytruett]

Did you drop the coraplast to do the welding? Thx. Joe

The front coraplast was spaced with some distance. The rear was pretty close. Remove 1 screw, bent back. held in place with a block of wood. No issues welding. No fires.

[Terrytruett]

We were the field repair you read. Yours looks just as good (nice welding) as ours that was done by lipperts road techs who were absolutely great. Lippert came through big time for us.
We had a bad weld fail while we were in FL a couple years ago, and Lippert sent a road tech who replaced the hanger. But not knowing how far we drove on it broken, it must have caused the opposit side to weaken and show stress cracking that no one could see at the time. Just as a precaution they decided to add the clips to all 4 hangers after the 2nd fix a couple weeks later that was done at the TN rally.

It will be interesting to see which part, if any fails next. With 14 ply tires, 3000# springs, and spring hanger supports, I'm guessing with a lot of tight turns, the wheel may break next. : )

[Cate&Rob]

@Terrytruett

I am sure that you have seen this (now ridiculously long) thread on broken spring hangers. https://www.mygrandrv.com/forum/show...-Hanger!/page3 . . .

Something to consider is that the free width of the hanger is greater than the length of the spring bushing. Sometimes by 1/8" or more. (Not exactly "precision" engineering!) As originally assembled, the spring hanger bends in to a width equal to the bushing as the hanger bolt is tightened. This is so that the nut on the hanger bolt can be tightened to its spec torque against the shoulder between the threaded and non-threaded sections of the bolt.

To reinforce a hanger, the LCI technicians use a "V Clip" similar to what you have used, but they only weld the legs of the V Clip on opposite sides of the hanger bracket (inboard on the leading side and outboard on the trailing side of each hanger) and then welded to the frame above at both ends. This reinforces the hanger while still allowing some flex to reach the bushing dimension. See the discussion and pictures around post 285 of the thread referenced above.

The concern is that if you over-reinforce the hanger at a width wider than the bushing, the nut may not be able to reach spec torque against the shoulder on the bolt. A related comment . . . the nut on the hanger bolt is a very specific smooth flange torque-retaining (stover) design. Each nut should only be used once and should not be replaced with the more commonly available flange nut with a serrated surface or with a torque retaining nut that does not have the flange. The correct nut is LCI PN 129767. I am sure there are equivalents from other manufacturers.

Rob

[Terrytruett]

@Terrytruett

I am sure that you have seen this (now ridiculously long) thread on broken spring hangers. https://www.mygrandrv.com/forum/show...-Hanger!/page3 . . .

Something to consider is that the free width of the hanger is greater than the length of the spring bushing. Sometimes by 1/8" or more. (Not exactly "precision" engineering!) As originally assembled, the spring hanger bends in to a width equal to the bushing as the hanger bolt is tightened. This is so that the nut on the hanger bolt can be tightened to its spec torque against the shoulder between the threaded and non-threaded sections of the bolt.

To reinforce a hanger, the LCI technicians use a "V Clip" similar to what you have used, but they only weld the legs of the V Clip on opposite sides of the hanger bracket (inboard on the leading side and outboard on the trailing side of each hanger) and then welded to the frame above at both ends. This reinforces the hanger while still allowing some flex to reach the bushing dimension. See the discussion and pictures around post 285 of the thread referenced above.

The concern is that if you over-reinforce the hanger at a width wider than the bushing, the nut may not be able to reach spec torque against the shoulder on the bolt. A related comment . . . the nut on the hanger bolt is a very specific smooth flange torque-retaining (stover) design. Each nut should only be used once and should not be replaced with the more commonly available flange nut with a serrated surface or with a torque retaining nut that does not have the flange. The correct nut is LCI PN 129767. I am sure there are equivalents from other manufacturers.

Rob

Thanks Rob!

Yes, I was careful to keep the V clip slightly smaller than the hanger. I did a test fit on all hangers. Guess I was lucky on quality of bends. I did not have any issues aligning bolts back up, they all seated properly and torqued to spec. I did use same nut, don't tell my wife. : ) Thanks for the part number, Ill order today before next trip.

I remember reading somewhere about the bend of the hanger being the issue. I agree 100%. I have personally experienced this with car/truck parts I have built over the years. Similar failure. After stretching the metal, hitting it with heat, now lets stress the hell out of it.

Thanks again!
tt

[J&G garage]

I first saw this fix when Rob posted his pics after the rally last year. I fabbed clips for my suspension from two pieces of steel so I could create an offset to facilitate welding one side of each leg of the clip (clear as mud?). Here's a pic when I was fabbing the clips.



These clips where welded into the spring hangers with the wet bolts installed to create the correct hanger width after welding.



We've got about 2000 miles on this fix over some ugly roads and so far so good.