Wheel shimmy while towing 2000lb trailer

2009 TRD off road. I have only ever replaced the right front bearing hub /assembly.
While towing my pop up camper I get some shimmy around 55-65 mph. Don't feel anything or barely perceptible when not towing. Stock suspension, no lifts etc. Had the 4 wheel alignment done last week. A tiny bit better but not gone.
Tongue weight of trailer is only about 250 lbs. Have the factory tow package which supports up to 650 lb tongue weight and 6500 tow capacity.
122,000 miles. I realize their may be may worn suspension parts etc at this much mileage but passed inspection fine and my trusted mechanic usually checks things pretty good.
Any thoughts? I don't think the tongue weight is much of a factor and I have driven with much more weight than that in the bed with no issues.

 

Have you had your tires balanced recently? Do you have the alignment specs? Some more positive caster may help with staying straight/sturdy when towing.

 

Unfortunately I don't have the alignment specs. I have not had the tires balanced lately but they don't have lots of miles on them and were done when purchased and installed?

 

How are the tires on the trailer?
I think I would jack up the truck and spin the tires one at a time and look for any bumps, abnormalities, or "tread walk", same thing with the trailer.

 

So sometimes when towing the front suspension is offloaded and this causes some issues.

Likely a worn ball joint that is simply behaving differently with the load off.

You need to have the front end inspected.

Also worn shocks will do this as well, but they are usually visibly blown if they are at the point of shimmying.

 

Trailer tires look like new with only a few thousand miles on them.
I will inspect the truck tires one at a time

 

Even with only 200 lbs of tongue wight?
Will have the front end checked but just did the alignment last week.

 

Its probably something in the trailer. Most likely tires. probably too small of a trailer to have brakes huh?

 

No. It has 10 inch electric brakes and a Tekonsha P3 brake controller. Trailer tires look good and only have a few thousand miles on them.

 

I disagree with it being a trailer issue. Those are obvious. Wonky trailers will shake your ass like a twerking convention at best, fishtail you off the road at worst.

I think you have a bad bushing up front, or something is loose. You only feel it when the front is slightly unloaded.

 

If you have carrier bearing check that and your ujoints for wear and or grease if you can grease them

 

What do you mean by “wheel shimmy”? I think people often have different definitions of pseudo-technical terms and it leads to disjointed and confusing discussions.

 

Well how about a small amplitude front end vibration at 55-65 mph. The truck is at the tire dealer right now getting brand new all seasons and balancing. We'll see if any improvement.

 

this use to happen to me with added towing weight pushing the back down at times where the front lifts up. Seems from my perspective it slightly changes the front tire dynamics of downward force applied to the road. When no towing or weight is applied to the back it does not happen. I think this may be exposing the tire imperfections more drastically, causing the slight steering wheel shimmy. When I got airbags installed it helped alot

 

That would make sense but I only have about 300 pounds of tongue weight. Doesn't seem like a lot?

 

My best guess is an unbalanced wheel/tire. Could be as simple as mud/snow/ice in the wheel or a lost wheel weight.

 

my 18’ jayco does 346lbs of tongue weight…so?

When the front of the vehicle rises the angle of “scrub” the tires have touching the ground changes slightly I believe.
Also, if the trailer acts as a cantilever to the vehicle (no tow/sway or roll control bars installed), then the handling will behave differently. This is my theory anyways…

 

Loading the trailer wrong can do that- is it happening when the trailer is empty?

https://youtu.be/w9Dgxe584Ss

 

pretty much empty. It is a pop up camper

 

Nice trailer! Do you have a weight distribution/anti-sway hitch setup on it? The electronic stability system in the truck is good for that, and it’s a stretch, but could the trailer be tracking strangely?