The tail is wagging the dog!!! - Page 3 - Diesel Forum

BayAreaBoater · 09-10-2005, 12:45 AM

Yes, the Rugged Trail T/A's stock from the factory.

I had the Pro-Comp 305 A/T's on my '01 with the 4" lift. Solid as a rock while towing.

Not anymore... [img]/ubbthreads/images/graemlins/mad.gif[/img]

camperman · 09-10-2005, 12:55 PM

I have an 04 X 4x4 PSD with Air Lift springs in the rear. I also have the BF Goodrich rugged TA tires still on the truck as it came from the factory. I tow both a 4000 lb boat (tandem axle) with standard drop down bar and a 10000 lb travel trailer with no sway or poor handling on either one.

I do run with a Henlsey on the travel trailer. It sounds to me like something is wrong with setup, tires or suspension. All tires should be at max pressure and unit should always be level. I would double check all hitch components and make sure there isn't something funky going on.

BayAreaBoater · 09-12-2005, 12:47 AM

Towed the Scout this weekend. Max tire pressure on both the Ex and the trailer. Seemed to have slowed down the wagging of the vehicle, but it is still there (mildly). At least when it occurs, I don't feel like I was going to lose control like before. It still isn't right. Or,at least doesn't seem to be right.

I think that I am going to call the buyer of my '01 Ex and see if he wouldn't mind if I took him out for a boat ride if we could use his Ex (my old one) to tow it to the ramp. I could get a feel for it now that I have been in my '05 for a while. See if it is just in my mind or factual... [img]/ubbthreads/images/graemlins/shrug.gif[/img]

Thanks guys!

Larry M · 09-12-2005, 06:31 AM

BayAreaBoater,

What are the ratings on your receiver, most are 500/5000 Load Carrying and 1000/10000 WD. Even at 4500 lbs you should consider some sort of WD setup and definitely for the 7500 lb trailer. Also some sort of anti sway would be a good idea. Not sure how all that works with surge brakes so that is also something you need to investigate. It appears that your tires are E-rated and airing them up to at least 70lbs is a good idea. D-rated tires (max press of 65 vice 80) have been known to flex more and contribute to handling issues. Also, you might consider getting one of THESE available thru CW and other sources for around $100. I have the 2,000 lb one and always check my tongue weight just before hooking up. You have to have the proper tongue wt on the ball or you are almost guaranteed of handling/sway issues. I like to have as much weight on the ball staying within the hitch and WD ratings and up to 15%+ of the weight of the trailer. For you 4500 lb trailer I would be running around 700 to 750 lbs tongue wt and for the 7500 around 900 lbs tongue wt. Finally as others have said your trailer has to be level.

Good Luck,

Larry

overcurrent · 09-12-2005, 09:38 AM

FWIW I tow a 24' boat - GTW about 8500# - without WD and it tows just fine (even before I added the Helwig). NEVER had a problem with this setup. The same boat/trailer also towed surprisingly well behind my 1994 F150 SC 4x4 (other than lacking horsepower with a 302.......)
I do not know what the tongue weight is but I suspect about 500#.

However, my friend with an 03 X and a similar size boat had all sorts of problems almost identical to what you describe.

In his case, (1) the tongue weight was too high and (2) the ball height was about 3" too low.

He now has a different trailer (long story) and with the right ball height and tongue weight now the rig tows perfectly without a sway bar or WD.

On the X, tongue weight and ball height are very critical!
Keep in mind that for a boat trailer (per the trailer manufacturers) the ideal tongue weight is 5-7%.

FamilyRide · 09-12-2005, 11:05 AM

There is a difference in boat trailers (tandem and triple) as they have a much lower tongue weight than other trailers, like TT's. The weight is much better balanced also. % usualyl is in the 5%-7% range. My Expedtion would handle my 7500# boats fine, all the way up to 90+ MPH (one time special circumstances) but was rock solid. Obviously no problem with the Ex. either although it has the advantage of weighing more than the boat rather than 2000# less as with the Expedition.

There is one company that makes a WD device for surge braks but no one I onw has ever tried it, or has needed to try it and I know a lot of boaters. There's also some issue with it as you still can't adjust it like you can a on a non-surge brake trailer wiht standard WD.

Something else is going on here and I'm really curious to know what it ends up being.

Larry M · 09-12-2005, 02:46 PM

I obviously was unaware of the 5 to 7 % tongue wt for boats, but it still begs the question on how you're safely towing 7500 to 8500 boats using a 500/5000 WC receiver if you're not using a WD setup. I'm not a boat tower so I guess I need to do somemore research on the boat towing aspect.

I guess one has to also take into account the specific aerodynamics of the boat being towed since most of the drag is from the aerodynamics of what is being towed especially the rear and under carriage. I could also see for OB motor type boats the number and how they are positioned could effect towing performance since they could act like "rudders" from an aerodynamic standpoint [img]/ubbthreads/images/graemlins/shrug.gif[/img]

I know I can change considerably the towing characteristics of my TT by changing the tongue wt by just 100 lbs or in one link in my WD setup.

Two rules of thumb that I look at personally is the 120 in of WB for a 20' trailer and 4in more of WB for each additional foot of trailer along with the two vehicle should weigh more than what is being towed. Now those a loosely for a Tag Type Trailer with a normal WC and WD hitch setup. The HA and Pullrite are exceptions and for me a my Van with a 138in WB weighing close to 9,000 lbs when fully wet and hooked up to a good sized trailer a trailer much over 8,000 lbs or 28 to 30 ft in length would have me looking seriously at either the HA or Pullrite hitches. Of course the last time I looked about a year or so ago about the only thing that would be good for a trailer above around 10K would be the 2K/20K Pullrite system since there weren't any "CLASS V" (i.e. the 1500/15000 WD systems avaiable for the F-series SD) made for the E-series. While my TT is only 6K lbs it's a funky profile with the rear being over 11' tall at the rear HERE

Larry

Larry M · 09-12-2005, 03:05 PM

As for this tongue wts for boats I checked around the internetand found for numbers for boat towing and they were 8%, 5 to 15%, 5 to 10%, and 10 to 15% so it just seems that 5 to 7% is a little low, but I can't explain nor do I understand the reason fo these low tongue wts for boats. It's a well nfact in general that too little tongue wt can certainly cause fishtailing and poor towing performance.

I readily admit I'm not a boat tower so I guess others will have to nail down the "real" tongue wts. for optimum boat towing.

Larry

Munkey · 09-12-2005, 09:30 PM

10% is the magic number no matter what type of trailer you have. Although most boat trailers don't have fixed axle location so you could slide your axle back just a pinch to achieve proper tongue weight if you boat is on the trailer right. The trailer manufacture would be able to send you axle locations for this reason.

FamilyRide · 09-12-2005, 09:54 PM

Small single axles may, but most of those have adjustable bow support that can be moved.

I don't know how you could move tandems or triples since you have leaf springs or torsion's to move besides, the ones I'm primarily referring to are trailers built for specific boats so everything from bunk size and placement to axle capacity and placment is set to that specific boat.

I'llsay again, I dont' know anyone that has ever had to change anything major like that one trailers built for their boat. Move the bow roller back and forth for slight adjustment, but most larger ones, like mine, are fixed.

The fact that it was fine with the other truck tells me somehting is going on with the truck, or something that has changed. Asuming nothing major has changed with the boat and trailer.

I don't see much difference even when I tow full of gas and water, (65 gal gas and 20 water) and I've even changed some weight at the stern with dropping the weight of the heavy iron intake and plenum adn cast exhaust manifolds and risers from my 7.4 MPI to lightening it up with alum intake and carb, and HP cast alum exhaust manifolds and SS risers. I may have dropped 100# back there. Still doesn't tow any different.

BayAreaBoater · 09-12-2005, 11:42 PM

Hey Larry (and others as well),

Thanks a bunch for your research. It's very interesting and useful information. I am going to buy that scale too.

Trying to get back to basics, as you recall, everything was fine with the trailers of both boats while towing with my '01 Ex. No problems whatsoever.

It was when I started to tow with my new '05 Ex when the trouble started. Nothing changed with the trailers (or load) at all. I swapped out my 4" drop ball mount for a zero drop one, which resulted in the ball being within one inch of the height of it on the '01.

Severe swaying back and forth to the point of pulling/jerking the Ex to an unsafe level. I actually thought that I was going to lose control. After inflating all of the tires to their max recommended pressure (they were at 60, now 85) it has limited the movement some, but not completely. My previous tires were Pro-Comp 33's with 50 psi in each (and the P/C 4" lift). Both trucks are diesel 4X4's.

I am going to order that scale and record the tongue weights, but really, there were no changes to the trailers, only to the tow vehicle.

I'm stumped... [img]/ubbthreads/images/graemlins/shrug.gif[/img]

Thanks again to all of you for your help.

Bruce B.

Larry M · 09-13-2005, 07:15 AM

Bruce,

The scale won't solve any problems, but it will give you a quick and easy way to judge and adjust tongue wt. My TT while only a 6K trailer is unusual because the axles are quite a bit further back and my tongue wt. with two batteries and 2 full 30lb propane tanks easily will run 900lbs (15%) and depending on how I load the trailer I can get that above 1,000 or down to around 750 so I have found the scale invaluable.

It would be hard to envision why this would matter, but the 01 X with the 7.3L would have a slighly different load on the axles than a 6.0L X because the 6.0L weighs several hundred pounds more. I can see your confusion in why one is different than the other since like you I would be scratching my head also.

Good Luck,

Larry

roofeditor · 09-13-2005, 07:26 AM

[ QUOTE ]
I obviously was unaware of the 5 to 7 % tongue wt for boats, but it still begs the question on how you're safely towing 7500 to 8500 boats using a 500/5000 WC receiver if you're not using a WD setup. I'm not a boat tower so I guess I need to do some more research on the boat towing aspect.

I guess one has to also take into account the specific aerodynamics of the boat being towed since most of the drag is from the aerodynamics of what is being towed especially the rear and under carriage. I could also see for OB motor type boats the number and how they are positioned could effect towing performance since they could act like "rudders" from an aerodynamic standpoint [img]/ubbthreads/images/graemlins/shrug.gif[/img]

I know I can change considerably the towing characteristics of my TT by changing the tongue wt by just 100 lbs or in one link in my WD setup.

Two rules of thumb that I look at personally is the 120 in of WB for a 20' trailer and 4in more of WB for each additional foot of trailer along with the two vehicle should weigh more than what is being towed. Now those a loosely for a Tag Type Trailer with a normal WC and WD hitch setup. The HA and Pullrite are exceptions and for me a my Van with a 138in WB weighing close to 9,000 lbs when fully wet and hooked up to a good sized trailer a trailer much over 8,000 lbs or 28 to 30 ft in length would have me looking seriously at either the HA or Pullrite hitches. Of course the last time I looked about a year or so ago about the only thing that would be good for a trailer above around 10K would be the 2K/20K Pullrite system since there weren't any "CLASS V" (i.e. the 1500/15000 WD systems available for the F-series SD) made for the E-series. While my TT is only 6K lbs it's a funky profile with the rear being over 11' tall at the rear HERE

Larry

[/ QUOTE ]

Hey Larry, the engine is sort out of most of the slipstream and I doubt this would come into effect unless you were going really fast.

roofeditor · 09-13-2005, 07:42 AM

Tongue weights are important, too little will will cause problems.

Moving the trailer axle back some if possible will increase the "polar moment." If possible try moving the axle further back, slight movement can bring about striking results.

Max tire pressure on the rear (EX) tires will reduce side flex.

Don't use max tire pressure on the front.....I don't know why but it makes the steering wheel touchy?

A set of Rancho 9000 shocks set on the max setting will be a tremendous improvement. You can back off when not towing because at mas they are a bit stiff.

A steering stabilizer on the front end also helps a lot.

Tires. E rated tires work much better than D rated. The Pirelli Scorpions worked much better than the Firestone steel-ex.

Tires on the trailer should be at max.

Biggest sway bar on the front and back of the EX also helps.

Raising the Ex up on lifting devices should make it worse.

Angle of the boat can cause problems. Angled slightly downward should be best. Angled upward should be bad.

Boat with a cover on may reduce airflow turbulence.

None of the ideas I have will cost much other than the sway bars. The shocks would be the first place I would spend money. I am a fan of Bilsteins but I tried both on my Excursion(s) and the Rancho 9000's worked better.

tfalk · 09-13-2005, 09:10 AM

More wood on the fire [img]/ubbthreads/images/graemlins/smile.gif[/img]

Replaced the shocks with Bilsteins in my 05, rides firmer, still jumping all over the road. If you hit a bump on the highway at 65 or so, it will change lanes all by itself. Stealer checked the alignment, said everything was 'in spec' except they adjust the toe slightly. No noticeable change in handling. Replaced the rear sway bar with the 30mm superduty bar, no noticeable change. Even thought of trading it in for an F250 but I'll get raped on the trade-in value... different STEALer told me $19K trade-in for an 05 XLT with 4700 miles [img]/ubbthreads/images/graemlins/confused.gif[/img] [img]/ubbthreads/images/graemlins/rolleyes.gif[/img] I have to admit, the 4 letter tirade they got in response was pretty funny....

Looks like my only option is to keep throwing parts at it until something works. Landyot's radius arms are on order. New BFG TA/KO 285's should be here in the next couple of days. I'm also ordering V and B springs. After that, it's off to an alignment shop to see where it really is. Sooner or later, something has to work...

What's annoying me is I built a kit car from the ground up, took 18 boxes of parts and made a driveable car out of it, but I can't determine what the hell is causing this problem. Just for reference, I had a friend drive it too. He's been trailering his Shelby for over 25 years, and he said the same thing, this thing just is not stable. At least it's not my (sometimes vivid) imagination.