March 25, 2004I'm using a '03 Silvy 1500 with a 5.3 engine, 3:42 rear end and heavy duty suspension to pull a 5th wheel stock trailer. The weight of the trailer varies depending on the number of horses loaded. From 4,300 lb to 7,400. Roughly 20% of the trailer weight is carried in the bed of the truck, so it varies between 880 lbs to 1480. According to GM's Trailering brochure, at 7,400 lbs I'm more or less within the weight limits of this truck. The truck has no problem pulling the trailer on flat land which we have around here. I wouldn't tackle the Rockies!
But I'm getting a vibration around 2,300 RPM that fades away past that, then as the truck accelerates it's real loud around 3,800 RPM which then is gone at 4,000 RPM. The vibration is loud - just like running over those hatch cuts on the shoulder of freeways. My dealer put shims in the rear springs which helped some but the vibration is still real loud at 3,800.
I had a 2000 Silvy 1500 with the 4.8 litre - same box, same rear end, pulling the same trailer. It didn't have any vibration at all. So I figure there's something wrong with my '03.
So I went past the dealer and complained to GM - they're sending down the zone service rep to check out the problem. In the meantime, I'm considering trading my 1500 for a '03 2500. Breaks my heart since my 1500 is LS and sweet and otherwise cherry.
Any opinions on this?