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.

[hddecker]

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

X2 what Captain says.

Dumb, dumb, dumb comment. Maybe he'd be better off towing at 80 MPH right, NOT.
That's why the right lane is for travel and the left lane for passing. The OP has just as much right to be on an interstate as you do, as long as he is maintaining the minimum posted speed, which can be as low as 35MPH in some places.

If you don't have a steering stabilizer get one, it will help., you might even consider one of the twin systems. Getting a bit more weight to the front will help also.

Also check the if steering box may needs adjusting, even though you have replaced it, it could need to be tightened up some.

[jerem0621]

rbpru wrote:
I occasionally get hit with the same effect. The odd thing is it is not constant.

Some days it is a noticable push, some days it is not there. Since I always set the cruise at 60 mph and hitch up the same way, I just attributed it to a shift in the TT loading due to changes in the gray, black and fresh water tank levels or perhaps a cross wind condition.

Though it can annoying at times, it is one of the variables encountered when pulling a TT. I have a half ton and a 26 ft trailer, the effect might be worse with a larger TT.

The thing to realize is that there is aerodynamic collision happening all the time with your rig, your rig is making its own bow wave... when a passing vehicle passes its bow wave has to push past your bow wave.

We can call this aerodynamic resistance.

Go with me on this....Airstreams and Minivans tend to do very well together (please no flaming here) from an aerodynamic perspective. The front of the vehicle is aerodynamic and there is no bed so the air slips over and around the van, the vehicle is relatively low so there is less aerodynamic force hitting the tires.. because they are tucked into the vehicle and not exposed from the front profile ... the air then hits the Airstream (which is very aerodynamic) and slips past it with relative ease.

Now, a truck like the OP's is quite literally as aerodynamic as a brick. That means that the Suburban is pushing a lot of air in front of it with no easy method for letting the air slip around it. The air that does get around the Suburban is then met with a high walled relatively flat profiled travel trailer... this air creates another pressure wake or "bow wave".

What the OP is dealing with is his bow wave he is creating getting disturbed by the passing vehicles bow wave. As the pressure from the passing vehicle approaches there is a disturbance created... and the vehicles are "sucked" towards each other... then as the passing vehicle actually passes there is a "push" that will push the passed vehicle away..

This suck and push is normal and is impacted by the shapes of the pressure wakes, speed disparity, and condition of the components in the vehicles used.

I suspect that everything is fine and the OP will get use to it as he gains experience. My only caveat is if the trailer is loaded tail heavy. That could create some instability.

Thanks!

Jeremiah

[rbpru]

I occasionally get hit with the same effect. The odd thing is it is not constant.

Some days it is a noticable push, some days it is not there. Since I always set the cruise at 60 mph and hitch up the same way, I just attributed it to a shift in the TT loading due to changes in the gray, black and fresh water tank levels or perhaps a cross wind condition.

Though it can annoying at times, it is one of the variables encountered when pulling a TT. I have a half ton and a 26 ft trailer, the effect might be worse with a larger TT.

[Shavano]

Knock off the flaming comments please. I'm not going to babysit this. Next one closes the thread.

Thanks

[Mr__Obvious]

As noted the semi approaches from behind and the bow wave pushes you while as it passes it sucks you back from the lower pressure behind the semi.

People who say they can't feel this remind me of those who have a 10,000+ lb trailer and claim they can't tell its behind them.

[stationaryfullt]

When I get blown by the trucks, I don't feel like I'm going to run off the road or lose control. It's one of those things that even though I know it's going to happen, it's still surprising every time.

In terms of getting a bigger tow vehicle, unless I move to a dually, there's not many vehicles that are "bigger/heavier" than a Suburban. But, find me a Chevy dually from the 80s that's not utterly destroyed or going for a fortune and I'll buy it.

While Chevrolet refuses to rate my Suburban for more than 2000 pounds because it didn't come with the towing package from the factory, the official GM literature for my year Suburban states that my engine/transmission/gear ratio combo is good for a 9500lb trailer and 16,000 GCVWR. A Suburban in any form is obviously capable of towing more than a 5x7 trailer of clothes.

Since I live in my trailer, it's always got a full load of food, clothes, water, propane, etc. I also accept that since I'm a full-timer, I'm darn near overweight on the GVWR of the trailer.

In terms of speed, I've been working my way up. The first time I towed the trailer with an inadequate WDH with no sway control, I could barely get above 45 before the trailer started swaying on me. With the Strait-Line and proper weight bars and sway control, I was able to do 55-60. I'd do 60-65 all the time once I get more confident in this bow wave issue.

I do appreciate everyone's comments and guidance.

[SprinklerMan]

I have an excursion and a 30 ft 10k trailer , had a similar problem ....found a pro pride hitch on craigs list for $ 500 ..... no problem now

[Gene_Ginny]

stationaryfulltimer wrote:
...
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

Some things I noticed:

Truck = 6040, Truck and trailer = 15420, meaning trailer alone is 9380#. With a GVWR of 9500# Trailer is loaded to 120# of max. I hope that scale weight was with trailer fully loaded with food, clothes, and water.

Truck only: Front:2660
Truck and Trailer Bars Hooked: Front:2480
Taking 180# off the front wheels is not good.

[Huntindog]

Mike Up wrote:


Anyone driving over 65 mph pulling a TT is nuts. WHY!!!! Because the trailer tires are only rated to 65 mph and know for a fact that going 70 to 75 mph will blow them. I've seen many family, friends, and coworkers blow their tires going at such speeds and have no idea why it keeps happening. Now they know and came to their senses and slowed down.

Not all of us are nuts. Some of us have upgraded to LT tires. That and a substantial TV allow us to tow comfortably at any legal speed. There is no reason it can't be done safely with the proper equipment.

If the big rigs can go 70-75 etc... We can too. With the right equipment.

[Huntindog]

DP

[campigloo]

I may have gotten my terminology wrong. Sorry. Full timer, it might be worth talking to a good front end mechanic and see if adding a steering stabilizer damper might help. Don't freak out guys, it's just a thought.

[jerem0621]

stationaryfulltimer wrote:
When I get pushed, it feels like it get pushed as one. I think the Strait-Line is really doing its job well.

I hate the 1500-2500 question, since I seem to always get yelled at for this. Technically, as the truck shipped from the factory 20 years ago, it was a 1500. Now, everything except the frame is now 2500 or 3500 parts. I try to not claim it's as strong and as good as a 3500, but it's definitely not a puny 1500 either...

The hitch is a Reese Strait-Line hitch with 1500 pound bars. The Strait-Line part includes built-in sway control. I need to pull a link or two to get the 100 pounds I'm short back on the front axle, but I'm already at the minimum links showing, so I need to tilt the head some.

As for pictures, they'll have to wait. I have a couple at home that I can possibly post.

I know exactly what you are talking about here!

I have had many 70's and 80's cars/trucks and that light steering is status quo for them.

However, there should not be a loss of control. Can you be dealing with a worn steering box or any other lose steering?

does it feel like the front end is on roller skates when vehicles pass? Is that an accurate description?

You may have already answered the tire question. Are the tires by chance Mud Terrain tires? They don't handle that great towing big trailers. Also, how are the sway bars on the Suburban?

Thanks!

Jeremiah

[Lantley]

BarneyS wrote:
A
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.

Barney

Barney is being very diplomatic with his advice. He is our experienced wise towing guru!:B
I guess you can go through the adjustment process. I did. However I did not eliminate the bow effect and achieve total towing satisfaction until I broke down and spent the money on a Hensley hitch.
Once upon a time a towed a 39' 10K loaded trailer with a Ford Excursion.
My story was similar to yours.
A hensley resolved my issues. I was skeptic until I actually towed with a Hensley. Now I'm a believer. The HA WILL eliminate your bow wave issue.

[TenOC]

Get a Hensley Arrow Hitch. Been there :E .. . done that. Now :B

[Mike_Up]

When I drove the bigger panel vans, the winds or passing vehicles made you grab the wheel with both hands and hold on. Pulling the 29' TT with P-rated tires is much better. But the LT tires will stop the left and right rocking, when you get hit by wind from the weather or a truck. Yes, heavier weight will help but the LT tires will help a lot.

Anyone driving over 65 mph pulling a TT is nuts. WHY!!!! Because the trailer tires are only rated to 65 mph and know for a fact that going 70 to 75 mph will blow them. I've seen many family, friends, and coworkers blow their tires going at such speeds and have no idea why it keeps happening. Now they know and came to their senses and slowed down.

Many places, the speed limit is 65 mph if pulling a trailer.