How many drop links do I use??

[altamont]

I think that I might be using too few links when hooking up my AS to my 2008 F250 SuperDuty. I use an Eaz-Lift hitch with 1000 pound bars. No problems in 15k miles but wonder if I am using too much tension on the bars.

When fully loaded I measured the distance from the top of the tires to the bottom of the wheel wells.

With NO trailer attached my front spread is 40.25 inches, rear is 40.25

Drop 4 links (firmest) I get 40.0 front, 39.75 rear. Hitch height is 17.5.

With Drop 3 links I get 40.5 front, 39.5 rear. Hitch height is 16 5/8 inches

Drop 2 links I get 40.5 front, 39.25 rear. Hitch height is 16.5

Any thoughts? I have had success with all configurations with no sway or difficulties.

[HowieE]

Dropping 4 looks good as far as weight transfer is concerned but the remaining question is how is the trailer riding as far a Parallel to the ground?

It is important with an Airstream that it ride parallel to the ground because of the type of axles. If the trailer is not riding level you may have to change the ball height and retry.

[altamont]

Good reply. I will check it out tomorrow when I hook up. As you can see, there is not much difference in ball height between the 2 and 3 links. I will shoot for level and see what happens.

[altamont]

I took the trailer out to a level surface and started with dropping one link. I could tighten the chain with my bare hand with almost no tension. I then dropped 2 and all was WONDERFUL. We drove some rough roads and arrived with nothing on the floor and all cabinet doors closed. What a difference between drop 2 and drop 3 (or 4) links. Handled like a dream and the ride was far less punishing to the truck and the AS

[Inland RV Center, In]

Originally Posted by altamont

I took the trailer out to a level surface and started with dropping one link. I could tighten the chain with my bare hand with almost no tension. I then dropped 2 and all was WONDERFUL. We drove some rough roads and arrived with nothing on the floor and all cabinet doors closed. What a difference between drop 2 and drop 3 (or 4) links. Handled like a dream and the ride was far less punishing to the truck and the AS

Always count the number links under stress. Never, dropped links.

In that way, you won't accidentially put an unnecessary twist in one chain, which will shorten it's length, making one side different from the other. Not good.

Andy

[dwightdi]

W/D bars are intended to equalize the load transfered from the trailer to the 2 axles of the tow vehicle. That is all. Setting of the ball height on the truck is intended to make the trailer run level. That is all it does. Adjusting the ball angle allows the w/d bars to have enough room to work properly. (It sets the number of links that you will run with.) During your initial set up adjustments, It should be your last adjustment after everything else is right. Counting links is what you should do every time you hitch up to go with all other things staying the same.

[Mikethefixit]

Personal Opinion ONlY
The measuring of fender heights tells you almost nothing. A trip to the CAT SCALE is a MUST. ITS gonna cost ya a few bucks but you will know exactly where the weight is in regard to links under tension. Every setup is different.
I use 6 links under tension is where Im at with my F350 springs and my Reese Straight Line. We get a ocean wave ride even as heavy as our truck is and nothing on the floor and or doors open after a 300 mile trip.
Again EVERY SETUP is different and only the CAT scale can tell ya exactly when the weights are close or equal. Depending on the TV you may have to search for the best axles weights to get the best ride.Its a lot of extra effort but will be well worth your time.
Roger

[HowieE]

I may be starting an argument here but a WD hitch is not designed or intended to transfer EQUAL amounts load to the 2 axles of the TV. There is not a TV out there that was ever designed to have it's load carried equally on both axles. The WD hitch is designed to insure that enough weight is placed on the front axle of the TV to maintain reasonable steering control. If the load was equally supported by both axles you would be riding on the stops of the front axles in many cases. The spring ratios, front to rear are quite different.

There is no standard as to the number of links that should be stressed or dropped. That depends on sever variables that are unique to each setup. The head angle is the biggest contributor with the weight of the bars being the second. These variables, along with the ball height, must be adjusted to give the desired stance of the trailer while transferring weight. Again there is no standard but with most truck as TV I shoot for a 60/40 ration of weight on the rear to front axle with the ration going down as you use heavier chassis TV.

Yes a scale is an advantage when setting up a system but not a requirement. The most important consideration when setting up an Airstream is to insure the trailer is riding parallel to the ground when finished. This is because of the type of axles used that do not have a compensating method between the axles. A trailer riding tongue high will have extra tongue weight. A trailer ridding tongue low will have reduced tongue weight. The latter can become a dangerous situation if the tongue weight is reduced below 10-12% of the trailer weight. This condition will increase the tenancy to sway.

Setting up an Airstream is not a 5 minute operation. It can take well over an hour to get it right.

[dkottum]

I'm still new at this, but my Airstream Owners Manual says the weight distribution bars should distribute the trailer tongue weight equally among three places, the tv front axle, the tv rear axle, and the trailer axle(s). The trailer must ride level, and this is a function of the hitch height, not the weight distribution bars.

My Equal-i-zer instructions do not mention weighing, only measuring wheel well distance to the ground, so that the tv sits lower on front and rear axles an equal amount when hitched, as when unhitched. If the same tv level is not possible, allow the front to sit a bit higher, but never the rear.

As for hitch ball angle, I find no specific instructions. However there is an interesting article by Andy Thomson of CanAmRV on hitch ball angle in the Summer 2010 issue of "Airstream Life" magazine, describing how a rearward angle can give additional traction in sharp turns, and additional stability at high speeds.

I can see the difference in my 1/2 ton '06 Tundra and your F250, in the amount of measured distance at the wheel wells. My Tundra is softer sprung and settles much more when the trailer is attached. Maybe that is justification for weighing heavier tow vehicles to get an accurate weight distribution, more so than lighter tow vehicles.

[HowieE]

Completely disregard the Airstream manual. That statement of Equal Distribution of the weight between the 3 sets of axles is a catch all statement written by a Lawyer who never had any mechanical engineering classes and never used a trailer.

Yes some weight is transferred back to the trailer axles but depending on the trailer length that will vary depending on trailer length and should not be a consideration when setting up the hitch. What you are interested in is some weight being transferred to the TV front axle to insure steering control. That amount will vary depending on the spring ration of the TV, and the length of the wheel base of the TV. A Bronco will require much more weight transferred to the front axle than an extended cab pick up to achieve the same control.

The comment regarding the head angle relate to a Reese hitch system. The Equalizer hitch does not have the level of design flexibility the Reese has, taking more of a brute force and ignorance approach. In order to adjust the bars it may be necessary to shim the height of the bar brackets.

[dkottum]

Regarding my Equal-i-zer hitch and head angle, it is completely adjustable to a downward angle. I did adjust it downward after reading the Thomson article, and on a test run it felt very stable. But then it felt very stable before, as well. Need some big freeway trucks and crosswinds, and a quick high-speed lane change to learn anything useful. My concern with this particular hitch is that the bars are very rigid (brute force approach, indeed) and too much downward angle may over stress the trailer a-frame, in turns.

I am trying to keep this within context of the O.P.'s inquiry, apologies if not.

[dwightdi]

I own both a Reese twin cam system plus an Equalizer system. The bars for the Equalizer system are twice the weight of the Reese bars and are much stiffer. This means the equalizer system has much less flexibility between the tow vehicle and the trailer when either encounter a bump or dip in the road. This leads to much higher forces being caused in the trailer and tow vehicle. The suspension system within the trailer and tow vehicle tries to compensate but the higher forces can cause more damage to the trailer. This is the reason Andy is always recommending using lighter weight (more flexible) W?D bars. I agree.

[Inland RV Center, In]

Originally Posted by dwightdi

I own both a Reese twin cam system plus an Equalizer system. The bars for the Equalizer system are twice the weight of the Reese bars and are much stiffer. This means the equalizer system has much less flexibility between the tow vehicle and the trailer when either encounter a bump or dip in the road. This leads to much higher forces being caused in the trailer and tow vehicle. The suspension system within the trailer and tow vehicle tries to compensate but the higher forces can cause more damage to the trailer. This is the reason Andy is always recommending using lighter weight (more flexible) W?D bars. I agree.

A simple test for excessive rigidity of the hitch set up, can be done by anyone.

When the rig is hooked up and ready to go, simply stand on the coupler and flex your legs as you would jumping up and down.

If there is a vertical movement of a couple of inches, your rig is in great shape.

If there is little to no movement, then your set up is "over rigged".

Excessive rated tow vehicles are one cause.

Excessive rated hitches, especially a couple of "so to speak" good hitch brands, are the other cause.

If the Airstream does not have a soft ride, it will reward you with damages to itself, that can become expensive, in time.

Yes, as many owners can attest to, even worn out torsion axles can and will punish the trailer.

The Airstream "pillow ride" for itself, is not a wish, but a requirement.

Andy

[Mikethefixit]

I agree wiff HowE. These systems are not designed and I don't think you will ever be able to get equal weights on TV axles or do I think you want too. I don't have my scale weights in front of me but if I remember correctly,when set correctly for my 1 ton,( Reese Old Style Dual Cam)I think there were about 200 lbs or so difference in the steering and the drive axle and that's where we get the best ride.
I don't want to argue the point and you are gonna do as you want. But I still feel that knowing excatly where the weight is and how much is there, so you can make adjustments accordingly. But pay no attention to me,I only dealt with weight distribution issues for 45 yrs when over the road,so what do I know. I still believe a trip to the CAT SCALE is worth the time and money. Oh 3 yrs of pullin my stream with a one ton has yielded no popped rivets or damage that I am aware of,an ocean wave soft ride is what we get.
GOOD LUCK