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Originally Posted by captmetal

Failure of sumo springs

thor outlaw 2013 37ls

this is the accounting of the failure of sumo springs under normal use.

I had installed sumo spring in the summer of 2017 to reduce body like many have done before me. Having driven about 7000 miles with them, they seemed to do the job, also installed the 2nd rear sway bar from roadmaster and the trac bar from blue ox.,

this year the big trip to yellowstone and mt rushmore all went fine until the end of the yellowstone trip, i do not pull a car i drive the coach everywhere.

I don’t drive fast over bumps or do crazy abusive stuff, this was the first trip with the garage loaded to max 2500 lbs, it was noted that the rear of the coach dropped 1 inch in height with the load. .

In yellowstone there was some construction and driving on dirt roads nothing any worse the normal pot holes we find in the city. (driven at slow speed) there was one area that was very rough i drove it at 3 mph through the 200 feet or so of bad roads, the coach did sway from side to side in a extreme manner, 2 or 3 sways (but within range of a evasive highway maneuver.)

during a brake check stop ( yes the brakes got hot ) on the steep pass, it notice the sumo springs had moved out of there normal vertical position and where bulging out of position.

It was obvious that the sumo springs needed to be removed and i really did not want to do it on the side of the road unless there was no other way.

I was able to get the coach to cody, wy where i had a local truck shop remove the sumo springs.

As can be seen in the photos on driver side the super heavy frame bracket was bent out of shape, the frame bolts holding one side on was sheared off and the frame bracket was hanging and got bent out of shape.

The passenger side the lower spring bracket was smashed and bent massively out of shape and
the huge amount of grinding marks on the lower bracket, this rubbing was done by the oem sway bar link and it needs to be replaced also.

The tires seemed to make it with out any damage .

The lesson learned here is that maybe the sumo’s work and reduce sway, but under some type of maximum movement the sumo’s will fail.

The sumo’s may fit the f53 frame but failure of the mounting system will result in other damage as there is no extra room for the sumo’s to move out of position. The rear tires could have easily been damaged for a later down the road nasty tire failure.

Since i drove the coach for 2000 miles after removal of the sumo’s i am not sure anymore if they are really needed, there seems to be a bit more body movement, semi’s passing mostly does nothing, crosswinds can be tricky i had some severe crosswinds during a eastern colorado route on my return.

It would be wise to check your coach for the condition of the sumo’s, i am amazed at the very heavy brackets being bent and the mounting bolts being sheared off, the forces here are incredible

I can see from the pic these were not installed correct, have who ever installed these fix it..