Attn: Bighorn 3750FL Owners. Structural Flaw?


Active Member
I have a 2015 BH 3750FL and right under both rear slides in the corners the walls are delaminating. One side has actually started to crack the fiberglass. This seems to have progressively gotten worse over the past couple years. I have only ever crossed paths with one other owner of this model and his was a couple years newer, but his looked like it was starting to delaminate in the same area. I have always inspected the caulking. Last summer removed all the old caulk and recaulked the entire rig with Lexel. It doesn't appear to be a water intrusion issue and if it is I have no idea where it would be coming from. The crack really makes me thinkit may be a structural flaw since there is very little wall structure due to slide and storage compartment cut outs. Are any other 3750FL owners experiencing this?



Staff member
I'd hazard a guess that when water runs down the seal, some is going inside in those corners.


Well-known member
We don’t have your model but have had frame flex on our 2013 3010 RE. Heartland stepped up both times and fixed new problems.

we had to prove to them via pictures and a video the problem existed.

I could be wrong but I think the real proof comes from watching these cracks (and other areas too) as you hook an unhook the truck. If there is differential movement you have a frame problem.

if you see no movement it is probably water intrusion damage....and I don’t think HL will help....but it would not hurt to call them.


Well-known member
I have that (2017) model Bighorn; I haven't given it a serious eye-balling but I haven't noticed anything similar.