2016 TEP with 5100's front @ 1.75 and 1" spacers in back - nearly level. I now have a 3,000 lb trailer with 300-400 lb tongue weight. When it is connected, and I have people and stuff in the back, I get sag.

I used to tow a 12K trailer with a F350, and it had airbags, which I liked.

Current trailer has a WD hitch, but I don't know that it needs it.

I do use the 4runner as a daily driver and for off-road play.

FWIW, mine has KDSS.

Thoughts from those who've been there?

AirLift 1000. Works great when needed.

There's a 20 threads like you just posted

If you have a weight distribution hitch and you have sag, the hitch is not properly installed and/or adjusted.

I tow a 3400-pound camper with ~400 pounds (varies depending on how much stuff she puts in the way back) of tongue weight using a Fastway e2 hitch and have nearly zero sag. Before the hitch, I had almost 3 inches of sag in the rear, and about 1 inch of rise in the front - unsafe, unbalanced. With the hitch, everything sits as normal, with the weight distributed over both axles.

A weight distribution hitch gets the most weight back to your front axle and requires no vehicle modification. You might try adjusting your hitch before making any other changes, hopefully, this will solve your problem.

I thought a WDH wasnt recommended on the 5th gen? I think I remember reading that the 4th gen V8 hitch was better suited because of the way it mounts. I think i read that in the main towing thread

No issues with a weight distribution hitch. The 5th gen hitch is bolted to the rear frame cross member in a semi-integrated fashion. Some see this as inferior to the old fashion hitches that typically bolt to the sides, or confuse them with various center mount hitches on vehicles with very low tow ratings. This does not keep me up at night, but you can always bolt on a 4th gen hitch if that is your thing.

I always defer to the manual for anything important. Unfortunately, the manual was written by engineers, lawyers, and product marketing in poorly translated engrish. It does not prohibit the use of a weight distribution hitch, p301 reminds you: "If using a weight distributing hitch when towing, return the front axle to the same weight as before the trailer connection." Gee, thanks, toyota. It also says: "If the gross trailer weight is over 2000 lb. a sway control device with sufficient capacity is required."

I've never used a "light duty" truck for towing anything beyond a 4 wheeler or utility trailer, the hitch made a world of difference for me pulling this camper. The feel is closer to that of a 1-ton, which is what I'm used to. No kick, very little pushing you all over the road.