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01-28-2022, 05:48 PM
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#1
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Junior Member
Join Date: May 2017
Posts: 3
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Tongue Weight and Sway
The sway I experience when towing my 26' Trail Runner is a little concerning and I am wondering if it has anything to do with weight distribution. I have all of the weights as measured from a CAT scale and my local feed and fertilizer dealer scale. But I am not sure about the calculations I should run or the rules of thumb for making sure I am in the right ball park.
The weights are as follows:
Truck - 8120
Trailer - 8760
CAT Scale Weights:
Steer Axle - 4620
Drive Axle - 5060
Trailer Axle - 7200
Gross Weight - 16880
I use a weight distribution hitch to transfer weight to the steer axle and I run all tire pressures at maximum rating on the tire or as listed in the door jam of my truck.
By my calculation I have a tongue weight of 1560. That is: Steer axle + Drive Axle - actual truck weight.
1560 (tongue wt) / 8760(trailer wt) = 17.8% of trailer weight on the tongue.
Perusing the forum I see that tongue wt should be between 10 and 15%. Am I calculating this correctly?
I can keep the sway to an acceptable level if I keep my speed down to 60 mph but sometimes that speed is a bit slow.
Should I be considering something else to reduce sway?
Thanks for any help you can offer.
__________________
Kevin D. Chilek
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01-28-2022, 06:03 PM
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#2
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Senior Member
Join Date: Apr 2021
Location: DFW
Posts: 1,648
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What is your tow vehicle?
__________________
2020 Chevy Silverado 1500
Forest River Wildwood XLite 263BHXL
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01-28-2022, 06:35 PM
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#3
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Senior Member
Winnebago Owners Club Workhorse Chassis Owner
Join Date: May 2016
Location: Kamloops, BC, 60 miles from the Center of the Universe according to the Rinpoche, of the SF monks.
Posts: 7,395
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You might need stiffer tires or possibly just more air in them. That is on the truck and possibly the trailer as well.
I would try going for a short drive without the WD arms hooked up to see just how much difference they are making. Then try different settings.
__________________
Happy Glamping, Norman & Elna. 2008 Winnebago Adventurer 38J, W24, dozens of small thirsty ponies. Retired after 40 years wrenching on trucks! 2010 Ford Ranger toad with bicycles or KLR 650 in the back. Easy to spot an RVer, they always walk around with a screwdriver or wrench in one hand! 
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01-28-2022, 07:01 PM
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#4
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Junior Member
Join Date: May 2017
Posts: 3
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Quote:
Originally Posted by carybosse
what is your tow vehicle?
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f350 srw
__________________
Kevin D. Chilek
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01-28-2022, 11:48 PM
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#5
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Senior Member
Outdoors RV Owners Club
Join Date: Oct 2003
Location: Hillsboro, OR, USA
Posts: 1,293
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I think that if you have the time I would compare the truck axles with and without the TT that will tell you how much change there is in the steer axle. You may need to revisit your hitch setup. My dealer set my ball too low and then over torqued the WD bars - needless to say the drive home was quite twitchy. Once I got the hitch raised and the bars cranked down the TT tracks great. Actually the more tongue wt you have the more stable the ride should be.
__________________
2017 Chevy 2500HD LTZ DuraMax Diesel Silver Ice Metallic
2017 Outdoors RV Timber Ridge 25RDS Mountain Series 4X Off Road Suspension Pkg
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01-29-2022, 12:19 AM
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#6
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Senior Member
Join Date: Aug 2017
Location: St. Louis, MO
Posts: 769
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I'm sure you've seen the youtubes on trailer sway but if not
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01-29-2022, 06:12 AM
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#7
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Senior Member
Join Date: Mar 2020
Location: Sun City West, AZ
Posts: 412
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What hitch are you using?
Can you post some pics of your rig hitched up?
__________________
2022 Rockwood Signature 8324SB TT, 36' 8", 11,115 lb GVWR
2019 Ford F350 CCSB, 6.2L gas, 2WD, 4.30 gears
2020 Keystone Cougar 'Half-Ton' 29RLKWE, 33'.3", 9500 lb GVWR - Sold
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01-29-2022, 08:20 AM
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#8
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Senior Member
Join Date: Nov 2018
Location: Beaver Dam, Wisconsin
Posts: 5,152
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With that much tongue weight and sway at 65 mph, there must be something wrong.
Weights may be incorrect.
Weight distribution may be incorrect.
May need anti-sway device installed.
Tow vehicle may have active anti-sway that is interacting with weight distribution hitch anti-sway.
Weight truck axles without trailer attached = F1 and R1
Weight truck axles and trailer axle with trailer attached = F2, R2, and T2
(F2 + R2) - (F1 + R1) = Tongue weight
The goal of weight distribution is to get F2 close to F1.
R2 must not exceed tow vehicle rear axle weight maximum.
T2 must not exceed trailer axle maximum weight specification.
F2 + R2 + T2 must not exceed tow vehicle maximum gross combined towing weight.
Nose of TT must be level to slightly nose down.
Tow vehicle must be close to level. Slightly rear down.
Rough Checks:
Front distance from top of wheel well opening to ground may be about 1/4 inch less when trailer attached and weight distribution adjusted. (Means close to unloaded axle weight.)
Rear distance from top of wheel well opening to ground may be about 1 inch less when trailer is attached and weight distribution adjusted. (Tow vehicle approximately level.)
Trailer axle weight will be a little higher when attached and weight distribution adjusted.
__________________
Paul Bristol
Kodiak Cub 176RD
Nissan Pathfinder 2015
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01-29-2022, 08:30 AM
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#9
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Senior Member
Join Date: Dec 2019
Posts: 797
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It is possible to have too much tongue weight as well that will induce sway. Just not as bad as having too much weight behind the trailer axle.
Can't find it now, but there is another YouTube video like the one posted above with a lot of weight on the tongue, it showed a tendancy to sway.
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01-29-2022, 08:32 AM
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#10
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Senior Member
Join Date: May 2021
Location: Asheville, NC
Posts: 2,335
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Persistent pretty much said it all.
But a couple of easy checks are:
How many inches is the coupler above or below the ball when not hitched?
When hitched how much tv squat is induced?
Presumably your trailer is tandem axle, but even with dual axles, a rear weight biased trailer will induce sway, as will a tongue too heavily weighted. Tongue @ 12% of wet weight is a good place to be. Finally, if your trailer is 26ft with rear biased axle location, the trailer will induce sway on a tv with a wheelbase that is too short. If this cannot be corrected or lessened with an ant-sway device. The truck and trailer are probably not well matched.
__________________
Jim. 2021 Canyon 3.6L, 2021b Micro Mini 2108DS
400w solar, 170AH LiFePo4, Xantrex XC2000, Victron 75/15 & 100/30, Champion 2500w df, 2Kwh powerstation
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02-01-2022, 09:59 AM
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#11
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Junior Member
Join Date: Feb 2021
Posts: 29
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Your driving an f350 with a 6,000 pound trailer and getting to ouch sway? Agree something must be off.
What year truck? Did you disable trailer sway n your truck settings? Could be working against your WDH. Is your trailer loaded to heavy in the rear? Are you traveling with full water tanks? If so where is it located?
I pull my 6,000 pound TT with a 2020 F250, no WDH and no sway control. I’ve never experienced any sway. You have plenty of truck for your trailer so something is off.
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02-01-2022, 11:08 AM
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#12
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Senior Member
Join Date: Oct 2016
Posts: 1,902
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YEP SOMETHING WONG. I tow a 27' that weighs 6500 on the scale ready to camp full of water. i tow it with a 1500 gmc crew cab, it tows prefect.
Jay D.
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02-01-2022, 12:37 PM
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#13
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Senior Member
Join Date: Apr 2003
Location: Kelowna, B.C. Canada
Posts: 3,085
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Quote:
Originally Posted by swduns
I'm sure you've seen the youtubes on trailer sway but if not
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Another similar one showing the added effects of speed;
Something is wrong with the OP's setup - he has adequate tongue weight and more tow vehicle than he needs. I don't believe 17.8% tongue weight would cause an instability problem in and of itself. While I'd run a WD hitch with a 9,000 lb trailer even with an F350 SRW, it should be stable even without one.
2 cents,
Dave
__________________
2022 Outdoors RV 25RDS, 2022 F350 dually, 6.7PSD, 10 spd, 3.55's
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02-01-2022, 12:58 PM
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#14
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Senior Member
Join Date: Apr 2003
Location: Kelowna, B.C. Canada
Posts: 3,085
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Quote:
Originally Posted by jrollf
It is possible to have too much tongue weight as well that will induce sway. Just not as bad as having too much weight behind the trailer axle.
Can't find it now, but there is another YouTube video like the one posted above with a lot of weight on the tongue, it showed a tendancy to sway.
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I don't think too much tongue weight typically results in sway; it's potentially bad for other reasons though (mostly dependant on the TV)
This is from Sherline but it's consistent with other articles I've read on the subject:
Too much tongue weight
can damage a trailer tongue, hitch or tow vehicle. Too
little tongue weight can result in a dangerous oscillation
or “fishtailing” of the trailer.
2 cents,
Dave
__________________
2022 Outdoors RV 25RDS, 2022 F350 dually, 6.7PSD, 10 spd, 3.55's
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