New shocks for '06 GMC Sierra 1500HD?? (Rear end bounce)

Thanks for all the input. The WD system I have is the Pro Series Weight Distribution System w Friction Sway Control. It shows specs of 10,000 lbs GTW, 1,000 lbs TW. So I don't think it's my WD system not being beefy enough. Honestly, with what I see as the drop with and without the WD setup, I almost feel like the truck's suspension doesn't need the WD setup. My trailer has a dry weight of about 5000 lbs with a hitch weight of 610lbs. The suspension on the truck seems to handle the tongue weight without needing much distribution. Without the trailer attached, rear height is 38 3/4". With the trailer, but no WD, it's 37 3/8". Adding the WD setup doesn't change it from 37 3/8. But maybe I'm just ignorant as a newbie with a TT setup.

One other tidbit, the prior owner of the truck apparently used it for a fifth wheel. So given that fact, and there being 66000 miles on it, would it make sense that the OEM shocks are probably due to be replaced? I don't know what the life expectancy on OEM shocks are, especially if there was a fifth wheel pulled.

How stout are your WD bars? Sounds like they may be too light for your tongue weight. Size them as close as possible to 15% of your trailers GVWR (without being under that weight). If the truck is not bouncing when NOT towing it's not likely shocks will help you much. Soft springs and light weight WD bars can cause what you describe very easily.
Good luck. / Skip

You may want to check into installing Timbrens. They have made a huge difference on my 2500HD hauling a Wolf creek TC.

5000 series. Have put them on all my trucks. Truck is going to bounce a little when you have weight hanging off the rear.

Just get the standard yellow ones. Great shock and you have a really nice truck.

I have not weighed things yet, but my front tires sit at 35 7/8 (ground to top of wheel well) without anything hitched. When I add the TT without any WD equipment, front rises to about 36 1/2. With WD I go to 36 1/8. So I am about 1/4" diff between nothing hitched and WD installed with TT.

Again, the bounce occurred with a boat too behind the truck. Just feels like the rear is soft. However, when I "rock" the rear up and down, then stop, it doesn't keep bouncing but stops right away.

How much drop do you get when nooked up? Have you weighed things yet?