Sorry to hear that. We had a serious frame issue on a previous TT that ended up in it being replaced under warranty. We got lucky. Lippert initally said the TT was "within spec"...
Lippert will always say that it's your fault because you overloaded it. Have you ever weighed it? Specs say it is 31.4' with 7545 lb GVWR. If 3500 lb axles, they're close to being maxed out and won't take much to over-stress them. Payload is 1650 lbs and for a TT that long is on the low side and can lead to easily overloading of the TT. Have you towed it with one or more full holding tanks? Frames have a slight "camber" front to rear and sag over the axles to the front and rear. Normally not very noticeable.
What type of frame? Is it the type that has faux I-beams made from 3 pieces of sheet steel welded together? If so, these are very flexible and can cause problems. Can you post some photos? Having difficulty picturing what the damage looks like. I would suggest taking it (if towable) to a good frame & axle shop for an inspection plus they can give you options for repair, if any. As mentioned, the only resolution you may have is hiring a lawyer. If you go to a frame shop and get a thorough report and photos you might try going back to the dealer and Cruiser with the evidence. Getting a lawyer to do this might be a good idea. Sounds like poor design, plain and simple. Cruiser is not alone in doing this unfortunately and one big cause is lack of any regulations on frames & suspension.
