Dealing with bow wave

[stationaryfullt]

I'm having issues with the bow wave from passing trucks. I have a Jayco 328RLS towed by a 1991 Chevy Suburban. I'm using a Reese Strait-Line WDH with 1500 pound bars. The front axle is about 100 pounds lighter than the unhitched weight, though I intend to fix that by adjusting the hitch a little.

I typically drive around 55mph on the interstate, and when the 18-wheelers fly by at 70, I get blown to the side a little. It's bad enough for me to be on-edge when towing, but I also don't have thousands of miles towing my camper under my belt yet.

I believe my bow wave issues may be partially due to the steering on my Suburban. The older 80s bodystyle Chevy trucks (for which my 91 shares bodystyles with) have very easy steering. The steering on these old trucks is so easy, that you can easily dry-steer from lock to lock with your pinky finger. Coincidentally, it's VERY easy to steer when the truck is moving. The entire steering/suspension assembly including steering box, tie rods, adjusters, ball joints, etc has been recently replaced and aligned, so they're all in good condition. I think the ease of steering is allowing me to be more easily blown around on the highway. Is this possible, and if so, would adding a steering stabilizer (shock for steering) improve the bow wave issues? How else other than watching the rear view mirror like a hawk and bracing for it can I help reduce the bow wave from passing trucks?

Thanks in advance. I'd really love to be more at ease when towing my home.

[Terryallan]

campigloo wrote:
I think what you are referring to is commonly called sway. All bumper pull trailers will do some of that, but it should be very mild..

No it is NOT sway. It is in fact the bow wave. Sway happens all by itself with no outside influence. The push pull of the trucks, and other vehicles is a normal thing. No matter what you do, you will always feel it to a point. But it should not be so bad as to scare you. The big trucks, and busses feel it as well. That you are going much slower than them is not the cause but that does make it worse.

Best thing. Is to do as advised, and return all lost steering weight to the front axle. Also, To get a stiffer tire, and air them to max. You will never rid yourself of it. but you can minimize it. I have a 31' Tt behind a 150. I have no sway, and the trucks never bother me. But I can feel them pass IF we are running vastly different speeds. But then when I drove trucks and busses. I could feel it as well.

Basicly all it is a difference in air pressure.

[IPegasus]

You should verify that the hitch is setup correctly. A couple of things to check: when the TV and trailer are straight in line, are the round ends perfectly in the pockets of the WD arm on both sides? With the WD arms hooked up, the front of the TV should be at the same height as when the trailer is not hooked up. The WD arms need a fair amount of pressure on them to do the sway control. As you said you may have to tilt the head to get the weight shift you need.

I have the same hitch and it is great but does take a little tinkering to get everything correct.

[nomad297]

Gdetrailer wrote:
the slower vehicle is PULLED towards the rear of the faster vehicle since the faster vehicle has a stronger VACUUM behind it.

The faster vehicle may have a lesser pressure behind it, but it certainly doesn't have a vacuum. Also, there is no such thing as a "stronger vacuum" or a weaker vacuum. A vacuum is a vacuum -- a space devoid of air/gas. You are confusing vacuum with suction.

Bruce

[Huntindog]

Desert Captain wrote:

Gdetrailer wrote:

stationaryfulltimer wrote:
I'm having issues with the bow wave from passing trucks. I have a Jayco 328RLS towed by a 1991 Chevy Suburban. I'm using a Reese Strait-Line WDH with 1500 pound bars. The front axle is about 100 pounds lighter than the unhitched weight, though I intend to fix that by adjusting the hitch a little.

I typically drive around 55mph on the interstate, and when the 18-wheelers fly by at 70, I get blown to the side a little. It's bad enough for me to be on-edge when towing, but I also don't have thousands of miles towing my camper under my belt yet.

I believe my bow wave issues may be partially due to the steering on my Suburban. The older 80s bodystyle Chevy trucks (for which my 91 shares bodystyles with) have very easy steering. The steering on these old trucks is so easy, that you can easily dry-steer from lock to lock with your pinky finger. Coincidentally, it's VERY easy to steer when the truck is moving. The entire steering/suspension assembly including steering box, tie rods, adjusters, ball joints, etc has been recently replaced and aligned, so they're all in good condition. I think the ease of steering is allowing me to be more easily blown around on the highway. Is this possible, and if so, would adding a steering stabilizer (shock for steering) improve the bow wave issues? How else other than watching the rear view mirror like a hawk and bracing for it can I help reduce the bow wave from passing trucks?

Thanks in advance. I'd really love to be more at ease when towing my home.

The part I bolded IS your main problem.

There is TOO MUCH difference in speed between you and the passing vehicle.

Honestly If you are truly and only going 55 on an Interstate road with posted 65+ speeds YOU ARE ON A "SUICIDE MISSION"..

I would recommend that if you don't feel "comfortable" towing at at least NEAR the speed limit ( say 60 MPH if posted at 65 MPH) then perhaps you should look for smaller lower speed limit roads.

Driving too slow is just as bad as excessive speeding since now you become an slow moving object in the way of others WANTING to go faster.

No matter how much you tinker with WD, hitch or even your vehicle suspension you will still feel the effect.

There are two things that you can do which will drastically reduce the effect..

#1, SPEED UP SOME as the passing vehicle approaches your trailer, doing so MINIMIZES the "difference" between your pressure wave and the passing vehicle pressure wave.

#2, MOVE OVER AWAY from the passing vehicles lane without going off the road (IE don't "hug" the CENTER LINE of the road), doing so puts SPACE between your pressure wave and the passing vehicles pressure wave. DISTANCE between vehicles reduces the effect of each others pressure wave, result is both vehicles will feel LESS pressure wave..

Doing BOTH of the above most likely will pretty much eliminate the effect you are feeling.

Congratulations on giving the worst advice EVER!!! :S

The OP is pulling a 35' TT with a half ton SUV and you think his only problem is going too slow??? The laws in a number of states, California comes to mind, require that vehicles towing NOT exceed 55. You have the nerve to shout at him that driving 55 constitutes a suicide
mission and then tell him to get off of the road because "you" think he should not be there. :R What color is the sun on your planet? :h

Yes, common sense and physics dictate that not hugging the centerline will help but not nearly as much as getting enough truck. More speed in an unstable rig is not the answer.

:R

He may or may not have enough truck... But the difference in speeds is a large part of the problem... Yes the law in CA limits trailers to 55... But that goes for the big rigs too... So that SHOULD eliminate the problem..

Park on the shoulder of a highway and feel the TT shake as the big rigs go by. The speed difference will be HUGE at 55-75 MPH. And so will the shaking of the TT. As the speeds get closer together, the shaking subsides.

[Gdetrailer]

CampingN.C. wrote:
I've heard cracking a window helps, but I always forget to try it!

I agree with the speed difference being (some) of the issue.

Window(s) square footage compared to entire tow vehicle AND trailer side square footage would be way to small to have any noticeable reduction to the effect.

Basically what you have is a series of high pressure "waves" being pushed by the vehicles. At the same time the rear of the vehicles has a very low pressure area (IE vacuum).

As the faster vehicle approaches the high pressure wave will affect the rear of the slower vehicle. This "pushes" the rear of the slower vehicle away from the front faster vehicle (if you watch in your mirror you will see the rear of the trailer MOVE away)since the faster vehicle has a BIGGER high pressure wave.

As the faster vehicle pulls beside you the effect is minimized some but as the faster vehicle starts to pass the slower vehicle the front of the slower vehicle is PULLED towards the rear of the faster vehicle since the faster vehicle has a stronger VACUUM behind it.

Equalizing the speeds so there is LESS difference in speeds reduces the overall effects not to mention putting some space between the vehicles also..

Has nothing to do with windows, WD or sway controls..

[Desert_Captain]

Gdetrailer wrote:

stationaryfulltimer wrote:
I'm having issues with the bow wave from passing trucks. I have a Jayco 328RLS towed by a 1991 Chevy Suburban. I'm using a Reese Strait-Line WDH with 1500 pound bars. The front axle is about 100 pounds lighter than the unhitched weight, though I intend to fix that by adjusting the hitch a little.

I typically drive around 55mph on the interstate, and when the 18-wheelers fly by at 70, I get blown to the side a little. It's bad enough for me to be on-edge when towing, but I also don't have thousands of miles towing my camper under my belt yet.

I believe my bow wave issues may be partially due to the steering on my Suburban. The older 80s bodystyle Chevy trucks (for which my 91 shares bodystyles with) have very easy steering. The steering on these old trucks is so easy, that you can easily dry-steer from lock to lock with your pinky finger. Coincidentally, it's VERY easy to steer when the truck is moving. The entire steering/suspension assembly including steering box, tie rods, adjusters, ball joints, etc has been recently replaced and aligned, so they're all in good condition. I think the ease of steering is allowing me to be more easily blown around on the highway. Is this possible, and if so, would adding a steering stabilizer (shock for steering) improve the bow wave issues? How else other than watching the rear view mirror like a hawk and bracing for it can I help reduce the bow wave from passing trucks?

Thanks in advance. I'd really love to be more at ease when towing my home.

The part I bolded IS your main problem.

There is TOO MUCH difference in speed between you and the passing vehicle.

Honestly If you are truly and only going 55 on an Interstate road with posted 65+ speeds YOU ARE ON A "SUICIDE MISSION"..

I would recommend that if you don't feel "comfortable" towing at at least NEAR the speed limit ( say 60 MPH if posted at 65 MPH) then perhaps you should look for smaller lower speed limit roads.

Driving too slow is just as bad as excessive speeding since now you become an slow moving object in the way of others WANTING to go faster.

No matter how much you tinker with WD, hitch or even your vehicle suspension you will still feel the effect.

There are two things that you can do which will drastically reduce the effect..

#1, SPEED UP SOME as the passing vehicle approaches your trailer, doing so MINIMIZES the "difference" between your pressure wave and the passing vehicle pressure wave.

#2, MOVE OVER AWAY from the passing vehicles lane without going off the road (IE don't "hug" the CENTER LINE of the road), doing so puts SPACE between your pressure wave and the passing vehicles pressure wave. DISTANCE between vehicles reduces the effect of each others pressure wave, result is both vehicles will feel LESS pressure wave..

Doing BOTH of the above most likely will pretty much eliminate the effect you are feeling.

Congratulations on giving the worst advice EVER!!! :S

The OP is pulling a 35' TT with a half ton SUV and you think his only problem is going too slow??? The laws in a number of states, California comes to mind, require that vehicles towing NOT exceed 55. You have the nerve to shout at him that driving 55 constitutes a suicide
mission and then tell him to get off of the road because "you" think he should not be there. :R What color is the sun on your planet? :h

Yes, common sense and physics dictate that not hugging the centerline will help but not nearly as much as getting enough truck. More speed in an unstable rig is not the answer.

:R

[CampingN_C_]

I've heard cracking a window helps, but I always forget to try it!

I agree with the speed difference being (some) of the issue.

[Gdetrailer]

stationaryfulltimer wrote:
I'm having issues with the bow wave from passing trucks. I have a Jayco 328RLS towed by a 1991 Chevy Suburban. I'm using a Reese Strait-Line WDH with 1500 pound bars. The front axle is about 100 pounds lighter than the unhitched weight, though I intend to fix that by adjusting the hitch a little.

I typically drive around 55mph on the interstate, and when the 18-wheelers fly by at 70, I get blown to the side a little. It's bad enough for me to be on-edge when towing, but I also don't have thousands of miles towing my camper under my belt yet.

I believe my bow wave issues may be partially due to the steering on my Suburban. The older 80s bodystyle Chevy trucks (for which my 91 shares bodystyles with) have very easy steering. The steering on these old trucks is so easy, that you can easily dry-steer from lock to lock with your pinky finger. Coincidentally, it's VERY easy to steer when the truck is moving. The entire steering/suspension assembly including steering box, tie rods, adjusters, ball joints, etc has been recently replaced and aligned, so they're all in good condition. I think the ease of steering is allowing me to be more easily blown around on the highway. Is this possible, and if so, would adding a steering stabilizer (shock for steering) improve the bow wave issues? How else other than watching the rear view mirror like a hawk and bracing for it can I help reduce the bow wave from passing trucks?

Thanks in advance. I'd really love to be more at ease when towing my home.

The part I bolded IS your main problem.

There is TOO MUCH difference in speed between you and the passing vehicle.

Honestly If you are truly and only going 55 on an Interstate road with posted 65+ speeds YOU ARE ON A "SUICIDE MISSION"..

I would recommend that if you don't feel "comfortable" towing at at least NEAR the speed limit ( say 60 MPH if posted at 65 MPH) then perhaps you should look for smaller lower speed limit roads.

Driving too slow is just as bad as excessive speeding since now you become an slow moving object in the way of others WANTING to go faster.

No matter how much you tinker with WD, hitch or even your vehicle suspension you will still feel the effect.

There are two things that you can do which will drastically reduce the effect..

#1, SPEED UP SOME as the passing vehicle approaches your trailer, doing so MINIMIZES the "difference" between your pressure wave and the passing vehicle pressure wave.

#2, MOVE OVER AWAY from the passing vehicles lane without going off the road (IE don't "hug" the CENTER LINE of the road), doing so puts SPACE between your pressure wave and the passing vehicles pressure wave. DISTANCE between vehicles reduces the effect of each others pressure wave, result is both vehicles will feel LESS pressure wave..

Doing BOTH of the above most likely will pretty much eliminate the effect you are feeling.

[Harvard]

Light steering can be associated with too little +caster. Do you have the alignment report available?

[stationaryfullt]

Not a boater, but what I read was that what I was experiencing was called bow wave and that sway was something different.

I've drug several car 2000-3000 pound car hauler trailers with 6000 pounds or better of truck on the back and not experienced any sway/bow wave/whatever you want to call it issues. But, those are also not 35 foot long walls on wheels.

[Dick_B]

X2 on the sway. The bow wave (you must be a boater) pushes on the large area of the trailer and tries to move the front end where it is attached to the tow vehicle. When it pushes the hitch toward the curb it takes the back end of the tow vehicle with it and the front of the tow vehicle heads for the passing truck.
More vehicle would help as well as the suggestion for moving to the right as far as possible. This phenomenom strength varies depending on the direction of the wind in my experience.

[stationaryfullt]

Old-Biscuit wrote:
What are you doing towing....thought you were 'stationaryfulltimer' :B


That's a 35' TT with a 7200# dry weight trailer with a GVWR of 9500#.

Have you ever been across a set of scales?

Sometimes I would like to actually go somewhere... 😉

I've been across the scales twice, but here's my last scale ticket readings:

Truck only:
Front:2660
Rear:3380
Gross:6040

Truck and Trailer Bars Hooked:
Front:2480
Rear:4660
Trailer:8280
Gross:15420

Truck and Trailer Bars Unhooked:
Front:2100
Rear:5200
Trailer:8140
Gross:15440

[Old-Biscuit]

What are you doing towing....thought you were 'stationaryfulltimer' :B


That's a 35' TT with a 7200# dry weight trailer with a GVWR of 9500#.

Have you ever been across a set of scales?

[stationaryfullt]

The shocks are new Gabriels. The tires are LT235/85R16 Michelin M/S tires aired up to 70 psi. They're 10-ply, load range E tires.

[BarneyS]

Adjusting your hitch to restore that 100lbs back on the front axle of the truck will probably help. You are towing a very large trailer with your Suburban and will never get rid of the bow wave effect completely. As long as you have your hitch adjusted correctly, the trailer loaded with the proper amount of hitch weight, the tires aired up to the proper amount, and no unusual suspension/alignment issues you have done just about as much as you can to minimize the effect of passing trucks.

The only other way I know of to cure that problem is to purchase a projection point hitch like a Hensley hitch. It will minimize the bow wave to a very slight nudge that will not affect the steering of your vehicle at all. The downside to the Hensley is that it costs quite a bit more than the hitch you have now.

I would try to get everything set up correctly and see how it goes. No need to spend a lot of money on a new hitch at this time in my opinion.
Barney