Bouncing while towing

[runningjill]

Bouncing while towing my 25f fc...have blue ox sway pro. Is this normal?

[rmkrum]

If you are describing the front if the tow vehicle feeling like it is bouncing up and down, it may be you are too light on the front end. This is usually referred to as 'porpoising'. It's not normal.

This indicates that you are not getting enough weight shifted back to the front end. If the rear of the tow vehicle is sagging and the front comes up above the normal unhitched height, that is what is probably going on. You need to either tighten your existing weight distribution bars more, or consider switching to stiffer (heavier weight rating) bars.

There are tons of threads on air forums about this. Have a look.


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[MAJORJDB]

While there are some very experienced folks out there who may have a better answer, thought I would try to help. I have only towed an AS for a year, but have towed other TTs for 25+ years. I have had bounce on certain roads (upstate New York) and none on others, so could be road conditions. Your tongue weight may be light (TW=9-15% of total trailer weight). I bought a tongue scale ($200+), need to weigh your trailer at trip ready load weight before you can calculate how much tongue weight you should have. Not sure how old your AS is but your axles may need to be replaced at 25 yrs or so. Pretty drastic, so start with the easy stuff first. Hope this helps...
Jim

[HiJoeSilver]

Could be depending on the road. If your front end is porpoising (bouncing up and down)a lot you don't have enough tension on the chains. Usually you want to go from the loose end down to the 7th or 8th link in the clamp. Do you know what weight your bars are for?

[slowmover]

The ones I see on the highway all over US "bouncing" are usually nose. down. Trailer must be dead level. That's a beginning on hitch lash up

[Mrjkq]

My only bounce is highway related. If your rig is set up right you should not bounce.

[AWCHIEF]

Ditto, I use the BOSP and the only bounce I get is also road related (Louisiana, uuk!). Cure is to slow down.

[n2916s]

Older segmented concrete roads can set up an oscillation that is self amplifying. It varies in severity in relation to the distance between worn expansion joints and the distance between your axles. If it tows great otherwise, the cure for segmented concrete is either avoidance or to vary your speed to break up the frequency...

[stsammy]

I will ditto that I've only experienced this particular version of hell in upstate New York. It seems to be the way the roads are grated / segmented

[aftermath]

I tow a 25ft with my Tundra and don't have a problem with bounce. I am surprised since you are using a PP hitch and from what is posted here on the forum these are the best hitches in the world. Perhaps you need to look at how it is set up.

My first reaction is that you have an issue with your hitch. You might want to get someone to help you with the PP. I get "bounce" but that is usually caused by rough road conditions and the ever problematic cement roadways out there.

[HowieE]

What is your TV and who set up your hitch?

Discounting those roads, concrete divides like route 10 in Louisiana, that are know to contribute to porpoising the hitch and TV are next for consideration. As mentioned above the hitch is more than likely not set up correctly

[streamer_a]

The porpoising thing is a function of the road - probably concrete with joints resulting in sea-sickness between 65 - 75 mph while towing. You'll find it gets less bad at certain speeds and goes away entirely on asphalt.

Airsafe hitch will remediate this.

[rmkrum]

I find that trailer and TV cargo loading seems to have a big effect. If I get porpoising, another 1/2 to 1" on the ProPride WD jacks totally stops it. Last time it happened I was a bit heavy in the truck bed and in the front of the AS. Pulled over in a rest area, cranked tighter, and no more bounce.

I should get off my butt and actually measure tongue weight with my scale and front fender height with a tape to get a better handle on this.


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[slowmover]

And then just run it across the CAT Scale three times. Still the best way to set the hitch. And most of all get a dead on reading of TV tire loads.

[runningjill]

Well - It seems that the hitch/Blue Ox was not set up correctly for our truck at the dealer. We had some very helpful Airstream owners at our campground help us out this weekend. We did have trouble with porpoising on the way from dealer to campground, but our new friends advised us on adjusting the hitch and sway bars. Our trip home yesterday was MUCH better. The only time we felt the bounce was on concrete sections of road. Our TV is a 2014 F150 3.5L Ecoboost/2017 25F Flying Cloud and as I said...the dealer set-up our hitch before we hit the road. We are brand new to RVing so this is a learning experience for us. So long story short...it was the hitch set-up!:roll eyes:

Thanks so much for everyone's help! So glad to have this forum!!!

[Vantair]

Similar to rmkrum example:

We have 25FT SS Rear bed 5300 dry 6300 wet. 2014 GMC 1500 5.2 4x4 short bed. 1488 cargo 9600 tow cap. EZE-Lift WD hitched using 2-1/2 links loose (used a through bolt/nut for the 1/2 cause 3 links too tough to yank in place. With 10 gal fresh water, 800 mile trip up and back to Sequoia Natnl Forest. Lot of pulls and decends.

Sweet ride all the way up on many road surfaces good to bad. Totally tight, balanced with NO porpoising. Never better feel. We've had it before but rocking gone on this trip.

On way back same exact loading but could only do 1-1/2 loose links due to uneven ground while hitching up.

BIG, BIG difference that 1 loose link made! Much more consistent porpoising, and bounce on the same roads back. Felt like a completely different set up and hitch.

Note to Self: Keep the 2-1/2 loose links set at all times !!!

[TinVenture]

Originally Posted by runningjill

Well - It seems that the hitch/Blue Ox was not set up correctly for our truck at the dealer. We had some very helpful Airstream owners at our campground help us out this weekend. We did have trouble with porpoising on the way from dealer to campground, but our new friends advised us on adjusting the hitch and sway bars. Our trip home yesterday was MUCH better. The only time we felt the bounce was on concrete sections of road. Our TV is a 2014 F150 3.5L Ecoboost/2017 25F Flying Cloud and as I said...the dealer set-up our hitch before we hit the road. We are brand new to RVing so this is a learning experience for us. So long story short...it was the hitch set-up!:roll eyes:

Thanks so much for everyone's help! So glad to have this forum!!!

Since you are running the Blue Ox setup, make sure you use molybdenum grease per the manufacture recommendations. Look for "Moly" grease. A rep at Blue ox told me that lithium grease is the same thing. After some digging I realized molybdenum isn't actually a base, it's an additive. It's designed for metal to metal applications.

You should fill the the two zerk fittings and grease the ball before every trip (at least I do). I just did this earlier on today. Good luck!