2017 Peterbilt Top Frame Failure

Anybody ever seen a frame fail like this? 2017 peterbilt truck/pup tanker. Crack occurred where the tank sat on the rail. Separated by a 1 inch rubber pad

 

Never seen that, havent seen much beyond twisted or sheared frames tbh, but armchair engineering me says rustjacking between sleeve and frame coupled with the tank pounding the frame a few times

 

How was the tank supported? Down the entire length of the rail or just in a couple of spots? Almost looks like the weight was concentrated unevenly on 1 point where it failed.

Can you post some more pictures? Particularly of the frame rails as they are, the broken piece of the rail (both sides plus the fractured surface) and of the fracture in the rail too. Even the tank/mounting if you could.

 

I always wondered why there was no coating or some sort of decent bonding between double frames. I’m sure stuff needs to move and flex but metal to metal seems wrong. At least to this dumb trucker.

 

I've at least got an associates in mechanical engineering and I agree. Very wrong. Most of the flex will be taken up in the cross members so the frames should have at minimum some nickel plating or similar for corrosion and also be bolted together obviously.

 

I Agree and also have never seen it before. I think some pertinent information is missing from this failure. Framerails themselves have an exceptional warranty above the base truck warranty. I am curious what Paccar has to say about this failure. I would say it would be rapidly shrugged off as a misinstalled body.

 

Sorry it took so long. Thank you everyone for your opinions. Attached is a photo showing how the tank was mounted

 

Nice crack in the tank saddle too.

 

Probably too much weight concentrated on a small footprint by the looks of it.

 

Guessing it may have been an oil field type tanker judging by the mud/clay in the picture so most likely loaded beyond rated weight coupled with off road use.