dog wagging the tail

[joe0508]

Can someone explain the sensation you get behind the wheel when you have tail wagging the dog.

[bid_time]

You don't have "Tail Wagging the Dog", because you have a motorhome and you're not pullng a trailer. What you have is sloppy steering.

[AJR]

Do a search on the net for “rv rear track bar”. I have a slight push from big rigs even after new shocks and a safe-t-plus installed. Both helped allot, but I did not listen to some good folks on the http://www.irv2.com/forums/f22/ forum that said do the rear track bar first.

This spring I will spend the $500 for a rear track bar.

[ol_Bombero-JC]

joe0508 wrote:
Can someone explain the sensation you get behind the wheel when you have tail wagging the dog.

You have it right in your post - but backwards in the thread title..:W

Also - with a MH the "dog" (MH) usually outweighs the "tail" (toad, or?). Should be easy to keep your tail where it belongs!

However, when towing a trailer - often it's vice-versa - the tail outweighs the dog.

Experienced TT folks usually have learned how to counter the 'vortex' caused by big rigs passing - by either applying power or applying trailer brakes keep the dog and tail in line.
Obviously, sway control devices help also.

~

Been to a lot of carnage on freeways - but always arrived *after* the incident.

I watched this unfold in "real time".
Fortunately the couple in the "dog", weren't injured.

It looked a lot like the YouTube video clip - except worse!

I was Eastbound on the CA 91 fwy - somewhere close to San Bernardino,
pretty heavy traffic, close to -or part of- rush hour/s.

Four lanes - I was in car with DW and two kids. (early 90's)
Up ahead I notice a 24' TT just like mine - in the 2nd lane from the shoulder.
It's being towed by an extended cab Ford Pickup - I had a Ford p/up also......but what *really* caught my eye - they're towing a utility trailer behind the TT.

I'm thinking....Yikes, is that dumb - or what!.:(

Then - this all happened in about 20 seconds - or less -
I'm in the 3rd lane over, and as I'm catching up - the guy with the double tow starts a move to the far right lane.
Maybe he was trying to get over quickly due to heavy traffic, or?

The utility trailer started to "whip" - which escalated to the TT.
I made some unprintable comment, and the wife who was dozing - went to "big eyes" instantly!

As I moved far left - and went pedal to the metal to get past, we got to watch the TT go full sideways, then straighten out - and then the pickup went full sideways.

I expected to see the pickup roll - or go over the embankment.

However, it "high centered" on the (dirt) berm and slid along like that scrubbing off speed, half over, half still on the roadway - the TT and utility trlr sort-of jackknifed in the two right lanes.

Mom & pop in the pickup most *certainly* needed at minimum a change of underwear - or maybe CPR..:R

Words can't do it justice! Clouds of tire smoke combined with clouds of dust when the front of the pickup went off the pavement.

Made a believer out of me!
You don't *EVER* want to be part of a "serious" tail wagging the dog - no matter what your RV "combo" consists of.

~

[Gjac]

Do you know how much weight is on the front tires vs rear tires? Do you have the correct ride height on your rear springs( are they sagging)?

[John_Joey]

joe0508 wrote:
Maybe this is not my issue because it doesn't seem as bad as the responses I'm getting.I don't pull a trailor this is a motorhome.I'm not sure if the feeling you get is similar but it does wander but not as bad as the posted are lmplying.

I was reading all the prior posts and wondering if they knew you had a Class A in your sig or not. 😉

For you it is when there is enough weight behind your rear axels causing your front tires to unload. This is a design flaw and can occur with tank placement or with the amount of coach overhang. Large class C's seem to be prone to this problem since they are built on van chassis.

You may feel it in your class A if you put as much weight as you can behind the rear axles and then get passed by an 18 wheeler. You'll feel the nose of the rig going back and forth slightly. If you tow a car it will help in keeping the rig going straight.

Hope that helps.

[joe0508]

I apologize for not telling my chassis.It is a p30/32 chassis,92 model.I had all kinds of things done to the front but not much to the rear.I had all steering components checked for tolerance,greased all points,new air bags in the coil springs installed,tie rods,supersteer bell crank on driver side,checked gear box,changed steering pump.I had three alighnments each time adding more caster using supersteer bellcrank specs.I made sure the coach set level from front to rear with no sagging.replaced cracked bushings in the front sway bar,Rear ones are fine per tech.It has helped a little with the wander and a lot with the sway.I am gitting ready to get a second opinion on the steering component tolerance along with the gear box before I go the track bar route.the track bar is the only thing I haven't tried and that only because the tech that checked it out and did all the work said he didn't think it needed one but I think the rear extends far enough out it could be causing my problem.

[koda55]

For me I had to constantly move the steering wheel back and forth to keep it going straight. As mentioned have you done the front and rear sway bar fix? You might need to add a trac bar to the rear end. After doing all these fixes I also found I as light on the front end. My front end was 5785 lbs. I My max was 7500. I put air bags on the front and rear. I carried 20 lbs i the front and 65 in the back. This added more weight to the front and I was able to drive with one hand. Also have you had your motorhome weighed with it as you would travel.

[Horizon170]

ford truck guy wrote:
I believe it is called "Tail wagging the dog" .. It is when you feel that you have to constantly correct the tow vehicle due to the trailer swaying too much behind you.The front of the trailer pushing and pushing the rear of the truck.

This can be caused by several different things including but not limited to--high winds...light pin weight , too heavy of a trailer period , and so on..
Like already stated , you will know when the tail is wagging the dog.. No doubt you will need to pull over and access what is going on....

AND to safely pull over with it wagging apply the trailer brakes ONLY hard until the wagging stops. Do not apply the prime mover brakes hard or the trailer may pass you. 😞
A good rule of thumb is to have 10% of total trailer weight on the tongue. That is for tag alongs, not 5th wheels. 5th wheels can be 15-25% I believe----depends on the truck.

[Ski_Pro_3]

The sensation feels like how it feels to stand on the beach with a wave that comes in, then the water pressure changes as the water goes back out, catching you off guard and almost sweeping your feet out from under you.

It's a feeling of a force you weren't expecting or can tell where it's going.

Ever been on an airplane and think you are going straight but can't walk down the isle straight because the plane is really in a bank? Just doesn't make sense to your mind.

[doxiemom11]

If it's the F53 chassis, do the easy fix - front and rear. Makes a world of difference!

[trop-a-cal]

The trailer has to have 60% of the weight in it in front of the axle or center of axles. That puts the weight on the towing vehicle which has to be within 4 inches of level to the trailer, by adjustment of the height of the hitch by making the suspension higher or lower to the point where the maximum tongue weight is not exceeded. If the weight in the trailer exceeds the design of the trailer and thus causes the trailer frame to twist, the beef up the frame or drop the weight. A welder can stiffen the frame up by using steel cross members that transfer the weight and eliminate the twisting. Of course if the hitch on the tow vehicle is not designed for the weight of the trailer then that vehicle needs to be replaced with a qualified set up for the trailer, or the existing tow vehicle can be modified by a welder and perhaps heavier suspension parts. Also tires can cause wag too if under inflated or being wrong tire for the weight. But 9 times out of ten it's the load in the trailer being to much to the rear, so just move the heavy stuff forward and down on the floor and not up in the cabinets, which causes top heavy wag.

[michigansandzil]

We drove past someone having this issue last summer. Scary stuff to witness. I can't believe they didn't pull off of the expressway. We managed to move over a lane and shot past them. No way did we want to be anywhere behind them.

[joe0508]

Maybe this is not my issue because it doesn't seem as bad as the responses I'm getting.I don't pull a trailor this is a motorhome.I'm not sure if the feeling you get is similar but it does wander but not as bad as the posted are lmplying.

[352]

downtheroad wrote:
Here is a video that shows, "dog wagging the tail."

Click Here

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