Shake/Vibration when Towing

[Caman96]

Can’t remember- have you tried rotating the tires front-back?

The reason that you can't mask this problem easily is because you don't have anywhere near enough weight on the rear of your truck while towing that trailer. You can see that just by looking at the picture. Because of this, you are gonna have to make things work perfectly.

You have a bad trailer tire, brake rotor, truck tire, or wheel bearing. If you can find a way to get the truck riding with an acceptable amount of weight on the rear, it will better mask your problem, maybe making it acceptable.

Brakes all new last fall, tires like new(balanced and then road force balanced), new rear suspension upgrade from 3/4 to 4/5 specifically for towing, here’s my front end:
https://www.gmt400.com/threads/eye-candy.57656/ Recently inspected by myself and shop.
Towing 2200 lbs. with an empty pickup is done by hundreds of thousands probably everyday. I’m not sure what you mean by adding weight to pickup box.
@Reluctanse i do rotate every 3k, wouldn’t hurt to jump ahead of schedule, but were rotated about 400 miles ago.

 

[Erik the Awful]

I wish there was an easy way to check drive shaft balance for us regular people at home

Back when I was in college we learned how to use a vibrating reed frequency meter and a hose clamp to check driveshaft balance. Good luck finding a vibrating reed frequency meter now.

What you can do is throw a hose clamp on the middle of the driveshaft, and then turn it 90 degrees at a time to see if it lessens the driveshaft vibration. Your driveshaft balance will likely be out at one end or the other, so you can then play with moving it front and rear. Once you find the clocking and positioning that makes it smoother, you can play around with moving it a few degrees in each direction.

 

[Hipster]

With weight added anything out of balance will be amplified, didn't read through this thread in it's entirety but didn't see or take note if the lawnmower sized trailer tires were balanced or not.

 

[Caman96]

Again, tires spec’d for this trailer, which are the typical tire for most clamshell snowmobile and this common Atv trailer. VERY common to see up in the north. The chosen diameter is to keep a low profile for loading either type machine. The spec for the tire is “C”, I chose a better “D” rated tire. The DOT approved tire is beyond what is required for this trailer. They are balanced, radials and correct 70 lb. psi.
Same set-up towed with 2018 Z71 perfectly. Tires are not an issue.

 

[Hipster]

well, balanced, is one less thing to worry about, but trailer tires that tend to sit also tend to flat spot so it's something that might be worth revisiting depending on how often the trailer is used, or if it has sat for long periods of time. A couple/3 months can do it.

 

[Caman96]

well, balanced, is one less thing to worry about. trailer tires that tend to sit are also tend to flat spot so it's something that might be worth revisiting depending on how the trailer is used.

That’s a great point. Although, they are radials and not typically associated with flat spotting like bias ply, I’ve heard they can but correct the themselves with usage.

 

[Supercharged111]

well, balanced, is one less thing to worry about, but trailer tires that tend to sit are also tend to flat spot so it's something that might be worth revisiting depending on how often the trailer is used, or if it has sat for long periods of time.

My Corvette will kinda flat spot the tires too, but after a couple of miles that all goes away. I'll vouch for those goofy looking tires, they're real popular with snowmobile trailers like he said. You'll see them all the time back in upper MI.

 

[Hipster]

My Corvette will kinda flat spot the tires too, but after a couple of miles that all goes away. I'll vouch for those goofy looking tires, they're real popular with snowmobile trailers like he said. You'll see them all the time back in upper MI.

See them around here quite a bit also, not being far from a national park where you can ride. It just seems a lot of things it could be, have been discounted or addressed. I have only worked in one shop where they had a vibration analyzer as Erik suggests, and I wasn't the one using it, but it's the go to method when all else fails to narrow in on an issue like this. Run out on wheels, rotors, tires, out of balance conditions that doesn't rear it's head until the weight is there. The fact the frames on the gmt400 trucks have been known to pick up some harmonics etc.

 

[Caman96]

have only worked in one shop where they had a vibration analyzer

FWIW, driveshaft was balanced 2 days ago.

 

[Orpedcrow]

Have you checked pinion angle loaded and unloaded? May need a slight shim with your new springs.