annoying bouncy ride pulling trailer

[BudinTenn]

I recently bought a new 18ft car hauler trailer and it shakes the truck at any speed. Like the truck and trailer aren't synchronized? Same thing when it is empty or with a 1200 lb bush hog loaded on it centered over the axles. What can cause this? I am pulling it with a 1/2 ton short wheel base truck. Thanks for your help.

 

[tcartwri]

Is the torque converter locking and unlocking ( change in rpm )

It's fairly common with a single axle to buck, but not so much with twins.

 

[Ryan03]

Is the trailer towing level or is it nose high. My 18 ft car hauler tows rough empty because it is about 1-2 inches high on the tongue. My road is very rough and every bump seems to crash right through the truck. Once the trailer is loaded with a car or tractor, the back of the truck settles and the trailer tows nearly dead nuts level, and the ride and handling are very good. If I am towing a light load I run a 5 in drop receiver, rather than the 2 in drop I run for heavier stuff. Towing level empty or light with the 5 inch drop it rides much better than tongue high with the 2 inch drop. A couple times on the interstate, I have ran across some heaved lanes where the bumps were in the exact wrong spot for the truck and trailer axle spacing, there is not much you can do in that situation besides trying to find a lane that rides better.

 

[BudinTenn]

Yes the RPMs change as they normally do in "tow mode".

 

[BudinTenn]

I do believe the tongue appears high. Next time I hook it up I'll check this out. How close to level does the trailer need to be? Most of the time I use it it will have less than 1500 pounds on it. Thanks.

 

[Marveltone]

I do believe the tongue appears high. Next time I hook it up I'll check this out. How close to level does the trailer need to be? Most of the time I use it it will have less than 1500 pounds on it. Thanks.

I'm probably a little ****-retentive on this, but I carry three different draw-bars to accommodate the tongue heights of the different trailers I have, just so they can ride as level as possible. I really feel this is a small expense and makes a big difference on ride quality as well as control and safety. All my trailers ride very smoothly as a result.

Joe

 

[Bigfoot62]

Even though you don't NEED it for the weight you're towing, a weight-distributing hitch will probably help that situation.

 

[Misfire]

Junk out of round tires is my bet. Jack the trailer up and check the tire run out on each wheel.

 

[SSdoxie]

I found that if not able to keep level then nose (front) slightly lower is better. I hook mine so level when empty and with light loads is still level. When I put the 3000+ lb. tractor on it, is about 1" lower in front (measured at front and back corners of deck). Ran mine this way loaded 1000 mi out to San Antonio, TX and back, other than a little extra grunt from the engine to get up to cruising speed I couldn't tell trailer was back there.

 

[meburdick]

Even though you don't NEED it for the weight you're towing, a weight-distributing hitch will probably help that situation.

WDHs are rated to re-distribute specific amounts of tongue weight. They tend to be rated for something like 800 lbs (as an example), redistributing 300-400 pounds of tongue weight (based on a typical tongue max of 500). If you use that on an empty trailer, you could end up with essentially no tongue weight (since an empty 18' car hauler will likely have about 300-400 lbs of tongue weight), and that would be bad. I, personally, would never attempt to use a WDH for an amount of tongue weight other than what the hitch was spec'ed for.

As for making sure the trailer is perfectly level when towing - I try to achieve a ride for the trailer that's as level as possible, but it often isn't overly crucial since the tandem axles are configured to handle angles without compromising the ride.

What, exactly, are you towing with? All details.. Year, make, model, hitch brand / rating, did the truck come with a towing package, what is the final drive gear ratio, what is the truck rated for in terms of tongue and gross trailer weight with AND without a WDH?

There are a LOT of variables that need to be understood. My truck came with the towing package, so the final drive is matched up well for pulling a 10k trailer. The standard final gear isn't as good, and some tow vehicles don't tow more than about 2500 lbs well because of their final gears.

 

[boggen]

one thing that trailers lack are shocks. and any suspension comes from some leaf springs. leaf springs being more rigid and when trailer is empty. basically causes trailer to jump up and down. when a tire on trailer hits a bump. vs the springs giving some allowing tires to roll over the bump.

once you get weight on the trailer. and in that weight on the springs. so when tires on trailer do go over bumps. the leaf springs actually "flex" causing the trailer tires to never come off the road but rather just roll over the bump. and folks generally experience much better ride once weight is placed on the trailer.

================
the current double axle trailer i have now, the wheels are almost centered between front and back of trailer. and for me, it seems to help if i raise the ball hitch/receiver up a couple inches to bring front tires on trailer up off the ground just barely. gives smooth ride when empty. doing this causes more tongue weight. and more weight to be placed on rear axle / leaf springs / tires. allowing the leaf springs to "flex" keeping trailer tires on the ground. vs trailer jumping off the ground when tires hit a bump.

on trailers where, trailer tires are further back on the trailer vs more near center, you might try dropping the ball hitch / receiver. so trailer front end is lower than rear. to bring the rear tires off the ground just barely or take weight off of rear tires some for a smoother ride when trailer is empty.

other words to above 2 paragraphs, it would be like turning a double axle trailer into a single axle trailer. by adjusting the ball hitch / receiver height to change tilt angle of the trailer.

=========================
since i have added a locked tool box to front of trailer. the extra 100lbs of weight has caused trailer to run extra smoother. without any adjustments to ball hitch / receiver empty or loaded up. that 100lbs changed difference between being in a vibrating chair, to seating down and just sinking into a cushy chair.

with above, you might want to think about ramps you use, and were you store the ramps. adding extra weight on rear of trailer to hold ramps = less tongue weight. perhaps going with a lighter made ramps, or moving axles on trailer further back on trailer to allow more tongue weight when trailer is empty / very light load on it. perhaps just welding / bolting on some weights to front of trailer.

 

[WD40]

X2 on checking out the tires for out of round or tread separation.
Doug

 

[Diamondpilot]

I recently bought a new 18ft car hauler trailer and it shakes the truck at any speed. Like the truck and trailer aren't synchronized? Same thing when it is empty or with a 1200 lb bush hog loaded on it centered over the axles. What can cause this? I am pulling it with a 1/2 ton short wheel base truck. Thanks for your help.

Get the tires and wheels balanced. I am in the trailer business and see this all the time. When they balance them have them check the wheels for true. I have found about a half dozen new trailer wheels that look brand new which are bent.

Anyone who says trailer tires dont need balanced is a idiot.

Chris

 

[PapaPerk]

Have the tires balanced. And make sure trailer is level with truck.

 

[SLHawkins]

Anyone who says trailer tires dont need balanced is a idiot.

Chris[/QUOTE]

There are two schools of thought on balancing trailer tires...some for, some saying it aint necessary.

Just as important however, is making sure that the tires are inflated sufficiently. And, you can't tell by just looking at them, or even kicking them sometimes. Many times an under-inflated tire (on a tandem axle trailer) will not show until you get a significant load on the trailer (much more than 1200#). When my empty trailers shake my truck, I immediately check the tire pressure. That has always been the culprit in my case, for both my tandem axle trailer with duals and my tandem axle trailers with single wheels.

Hawk

 

[meburdick]

If the trailer was sitting for a long time, the tires could have developed flat spots too.

 

[Misfire]

Get the tires and wheels balanced. I am in the trailer business and see this all the time. When they balance them have them check the wheels for true. I have found about a half dozen new trailer wheels that look brand new which are bent.

Anyone who says trailer tires dont need balanced is a idiot.

Chris

I'll tell my tire guy that you said he's an idiot. :laughing:

I use a really popular local tire shop. It's one of the biggest I've ever seen. They said I was the first person who had ever asked them to balance trailer tires.

Misfire

 

[Diamondpilot]

I'll tell my tire guy that you said he's an idiot. :laughing:

I use a really popular local tire shop. It's one of the biggest I've ever seen. They said I was the first person who had ever asked them to balance trailer tires.

Misfire

I am telling you it makes a difference. Think about it, its a 40# spinning disk and then once you have it done you will be amazed at how much weight it takes to balance them. On average trailer tires and wheels are of lower quality than auto stuff.

Chris

 

[SLHawkins]

I agree that it makes a difference. But similiar to Misfire, when I asked the tech at the tire shop to balance the tires on my trailer, I got funny looks.

Hawk

 

[PapaPerk]

Yeah not balancing trailer tires makes no sense. They are rotational mass... balanced rotational mass will not vibrate. Period.