car hauler vibration

[Living in the Past]

Have a question on tandem axles and vibration. I have a 7,000# 18' car hauler, PJ Trailers. Bought new in 2008. I have towed it with three different vehicles. 2000 LC, 2004 V8 4X4 4Runner and 2010 5.7 V8 4X4 Sequoia. It has always towed the smoothest behind the 4Runner. Worst behind the LC. Vibrated both loaded and empty, with empty being the worst. The Sequoia fair loaded and worse empty. Not sure what the tandem setup on the axle is called but the vibration seems worse when the nose is higher as compared to being level. Is this setup designed to tow level and I should buy adjustable drop hitch to level it out? Or is it just something about each vehicle that causes it to tow different behind different vehicles?

 

[ntsqd]

All mfg'd trailers are designed to be towed level. If you're not, that could be the problem.

 

[titanpat57]

and lots of tongue weight...tongue weight is our friend

 

[Living in the Past]

and lots of tongue weight...tongue weight is our friend

That becomes a problem when towing it empty. When I load a vehicle I watch the rear wheel to be sure I getting weight on the tongue just not too much. In the past I watched the axle to see how much seems to tow best. Measured the 4Runner this morning before my wife took it to work. Plan on measuring the Sequoia and picking either a adjustable hitch or one that equals the difference between the two figuring the 4Runner might sag a little more.

 

[titanpat57]

That becomes a problem when towing it empty. When I load a vehicle I watch the rear wheel to be sure I getting weight on the tongue just not too much. In the past I watched the axle to see how much seems to tow best. Measured the 4Runner this morning before my wife took it to work. Plan on measuring the Sequoia and picking either a adjustable hitch or one that equals the difference between the two figuring the 4Runner might sag a little more.

The Airlift 1000 bags are the single best mod you can do to increase load handling and safety while towing with the 4runner. Also as stated earlier. ..level is very important.

Go to the salvage yard and get a toolbox for the nose if you need extra weight, or move the spare up there.

 

[Elbert]

assume you have checked for bad tires and improper inflation...etc on the trailer. Also assume the tires are balanced...

 

[Living in the Past]

assume you have checked for bad tires and improper inflation...etc on the trailer. Also assume the tires are balanced...

I've balanced the tires in the past with no difference but that was quite a while. Probably should balance and rotate them. Trailer doesn't get use much and keep it covered. What is a good tire pressure? I'm running about forty-two pounds. Wonder if a lower pressure if would trailer smoother empty?

 

[Elbert]

I setup a trailer to tow level loaded (trailer level). Always!.. I doubt the vibration has to do with the trailer not being level, but nevertheless the trailer should be level loaded. There will be some vibration towing an empty trailer... I have a 20ft locally made dual axle 10.4K metal deck trailer which tows great, but I do have more road feedback when the trailer is unloaded and I would not really call that vibration. If you overload the trailer or exceed you truck capacity that can add to your issues. Vibration issues are normally in the tires or potentially maybe the hub bearing..

I run e rated LT 16 inch tires (all season hwy tires) on my trailer and I'm about 5 to 10lbs or so from the max air pressure the tires are rated to run at. I just got back from 3000 mile + trip with the trailer...no issues.

Vibration is normally in the tires as I noted...one tire or multiple tires under inflated, worn or defective tire, warped / damaged wheel. Tires should be close to their proper air pressure rating...even more important with loads, as the tires will heat up if they are under inflated.

I also position my towed vehicle on the trailer where the trailer rides fairly level. I tow with a 2500 pickup and you can buy different trailer ball mounts to position the trailer hitch ball at the proper height, and my trailer has an adjustable coupler too, that I'm moved to level the trailer. Its been my experience that if you have the the loaded / towed vehicle either too far forward or too far to the rear on the trailer you will introduce sway and other poor ride characteristics.

I have marked my trailer so I know exactly where the "sweet" spot is for my LC that I tow to sit at on the trailer, otherwise get the vehicle up on the trailer and move it to where the trailer sits level. Of course you can't have the towing vehicle dragging its @ss and have the trailer pointing down hill that's going to be a problem. Depending on various variables related to your tow rig, the receiver, the trailer ball mount and the trailer coupler you may have to get the trailer sitting nose high before you load it. All depends on your setup.

I tow all things with the trailer setting level loaded (to the extent that I can manage that)

 

[Elbert]

This is how I tow at present and its been great...great improvement over the old days using a uhaul or other borrowed trailer. I don't worry about the trailer and its a smooth ride and all I have to worry about is not going too fast.

 

[Elbert]

I've got a different trailer ball coupler now (HD Bulldog) but this shows the height adjustment

on the trailer side.