Weight Distributing Hitch Questions and More

[Bird]

I have had both Eaz Lift round bar type WD hitch and Reese trunnion bar WD hitch, and wouldn't give you a nickel for the difference. They both work well. I did not think I'd like the Reese dual cam sway control because a friend had that and it makes a lot of noise (popping and squeaking) when turning and while it is adjustable to some extent, it is not adjustable to the extent that the Eaz Lift friction sway control is, so that's what I used and liked. Now a lot of people say the sway control isn't necessary, and they're right. Neither are seat belts, air bags, trailer brakes, etc. "necessary". They only become important when you need them. Having been an RVer for many years, I lost count of the number of RVers I visited with who had a brand new rig and I learned they had a new rig because they wrecked their previous one. Almost without exception they said their dealer didn't tell them about sway controls until after they wrecked their first rig. But you can bet every one of them had a sway control on the new rig.

I think others have pretty well covered the topic, but I don't remember seeing anyone mention that you can buy the spring bars specifically for different weights; i.e., 500#, 750#, 1000# bars are different strengths. And while you don't have to do anything to the hitch receiver on the vehicle, you do need a different hitch head; one designed for the type of bars you're going to use. You usually just buy the complete assembly together.

Incidentally, Trailer hitch, hitches and bike rack (800)298-8924 seems to have about as good a website with illustrated hitch equipment as I know of.

 

[john_bud]

Bird,

I was always told that sway control is important for enclosed trailers where the wind is a big impact, but an equipment trailer with much less side wind area it isn't a big deal.

Thoughts?

jb

 

[KeithInSpace]

Have no idea how sway control works, but I've personally seen utility trailers swinging wildly/violently from one side to the other. In both cases, they were overloaded vehicles that weren't generally suited to towing (cute-ute in one case, green wood-sided station wagon in the other).

In both cases, the vehicles were loaded in addition to the loaded trailer, greatly lowering the ball such that it was much lower than the axles.

It is my (limited) understanding that you ALWAYS want the ball up and the trailer flat or "sloping back", even when loaded, to combat sway as a result of bad towing geometry.

Sway because of wind is a whole different monster, but I am 100% certain you can have loads of sway with a low profile trailer in no wind.

That would further the argument that WD hitches are a first line of defense against sway. They promote proper geometry at the ball.

 

[Bird]

Bird,

I was always told that sway control is important for enclosed trailers where the wind is a big impact, but an equipment trailer with much less side wind area it isn't a big deal.

Thoughts?

jb

John, it just seems logical to me that a tall, solid sided trailer (or any other vehicle for that matter) is going to catch more wind, so assuming all other factors were equal; i.e., weight, load distribution, type of hitch, weight of towing vehicle, etc., yes, the wind would have more of a sway causing impact on the enclosed trailer, but as Keith said, you can certainly have plenty of sway with an equipment trailer, so to me, yes, it's a big deal. But as with many others, I used a good sway control and weight distributing hitch with my travel trailers, but I didn't have one on my equipment trailers. In my case, I wasn't usually going very far, I wasn't going very fast, I didn't have a heavy load, and I was always very careful about weight distribution. I say always because I scared the dickens out of myself when I was 16 years old, fortunately recovered with no accident and no damage, but I never forgot it.

Of course, I drove vehicles for years with no seat belts, no air bags, no power steering, no power brakes, no anti-lock brakes, etc. I'm not saying a sway control is an absolute necessity, but it sure does add to the safety factor.

 

[MossRoad]

I still cannot find the GCWR of my Suburban. The dealer cannot search back to 1993(at least that is what they are telling me). Anyone have any suggestions?

 

[zzvyb6]

Sway control is not intended to solve the sidewind gust load problem but will help it. Sway control is intended to add a yaw damping moment to the combination to counteract the natural tendency of the truck and trailer to have out of phase yawing conditions. This situation has a very significant speed causation factor, it gets (worse*squared) as you go faster. This can be a problem when the tongue load fraction is under 5%, or the vehicle speed increases (as in going down a long hill) in an unintended manner. You will reach a 'critical speed' making the combination unstable as in jack-knife. Trailer rollover is the principle mode of failure for travel trailers. Yaw damping also results from the use of multiple trailer axles. This allows you to have a lighter tongue load to trailer weight for the same combination load. The cam or friction dampers try to do the same thing. The cam lobe system enforces a predefined tongue position, The friction device adds yaw damping moments to the tow angle dynamics. There is a difference, though. The friction damper looses effectiveness once it starts to slide: the damping force is a constant at all times during the 'event'. If the tow angular velocity keeps increasing it can not stop it. The cam system adds a stabilizing moment that is proportional to the yaw angle instead of a constant value, hence is more likely to help you if you really get bent out of shape (as in a sudden double lane change).

In either case, the equalizing hitch should be alway set to maintain a level tow vehicle frame position. This keeps the front axle steer geometry and the rear axle steer geometry at manufacturer recommended positions. Now, just in case you think the rear axle doesn't steer on a front steered car, you are very wrong. There is considerable deflection steer (sideforce based), steer from roll (geometry) and steer from braking/traction (deflection and geometry) in all vehicles no matter who makes them. While its only a degree or so, tires, especially heavily loaded ones, punch out thousands of poinds of sideforce per degree, so it has a major effect on your trucks heading angle. The trailer just adds some more load to the equation(s). Keep in mind that the hitch without EQ loads the rear tires as well as unloading the fronts. This is also a geometry and a tire sideforce loading concern.

Remember the old discussion about greasing trailer balls? Well a dry ball also serves as an effective friction damper and will help you if you have nominal wind or driver induced course corrections. As I recall, those 'ex-Spurts' swore that you need to grease them. But they've probably never run engineering tests on these systems as I have, so, I stand by my statement: if you want your balls greasey, grease your ball.

AND, the place we do all this rocket science is here: (Google Earth it)

42.36'.48.59"N
83.40'.49.70"W

 

[MrJimi]

MossRoad, from your other post on this I think you will be fine. Most Suburbans have a huge gas eating engine and will tow the world ( well, almost )
Go for it

 

[Egon]

greasing trailer balls?

This sounds interesting. Tell us more please.

 

[MossRoad]

This sounds interesting. Tell us more please.

Yes. Please do. I was always told to grease them up or they would wear out really fast. Of course, I always manage to run my shins into the hitch and besides getting a nice grease stain, I also get a nice lump!

 

[KAB]

I still cannot find the GCWR of my Suburban. The dealer cannot search back to 1993(at least that is what they are telling me). Anyone have any suggestions?

My 90 Blazer was rated for 6000# with the 5.7. If you don't find an answer before I my next trip to the Akron area I will stop and see a guy that should have that information. I will watch this post to see if you get an answer, if not, I will see if he still has the 93 books. I should be there in the next 2-3 weeks.

Kurt