Originally Posted by Subaru297
The trailer is 3500 lbs GVWR so technically it may not need a WDH. The usual 500lbs cutoff (for needing WDH) would be 15% of the trailers weight. And 500lbs shouldn't be affecting a Tahoe that much.
In an above post I mentioned that the Tahoe has a soft suspension. That's typical of SUVs, even full size truck based SUVs. I towed a Kiwi 17A (3500# GVWR) trailer with a Suburban, and yes, I needed WD. There is no "cutoff" weight. The need for WD is determined by how much weight is taken off the front wheels. There is a spec for this in the tow vehicle's manual.
The rating on the hitch is what the hitch itself can handle, and is not the same as what the limits of the vehicle are. More often than not the hitch is rated higher than what's listed in the manual. The real limitations are often the frame and rear suspension.
True, not all trailers need WD, for example no need for it towing a small trailer with a 2500/250 series truck. But in the case of the OP, WD is the way to go.