Hitch height

[DougGirling]

Quick question regarding hitch height: I've measured from the ground to the inside of the hitch on the trailer (with the trailer level), measured from the ground to the top of the hitch receiver, and measured the height of various hitch balls in the store. It looks like I need to buy a hitch with a 3" - 3.25" lift.

The problem is that the hitches come in 2" increments. I can get a ball with a 1" extension to make up the difference. However, the whole back end of the vehicle will sink with the weight of the tongue and the crap that we always seem to travel with.

So, the question is: when I buy my hitch, should I fine-tune the height to 3", or go for 4" and rely on the back end sinking an inch. (To put it another way, is there a good - or even adequate - rule of thumb about how much sink to allow for?) Oh, the tow vehicle is a Dodge Grand Caravan minivan.

Thanks in advance,
Doug

[TPMcGinty]

When I needed to figure mine out I went to Northern Tools. The guy that helped me let me take the different hitches out with me and see which one fit the best. I've got a 4" drop.

[Dale M.]

Rise and drops are in all different sizes.... There is no set increment....

http://www.etrailer.com/pc-BMC3~40331.htm

http://www.etrailer.com/pc-BMC3~4281.htm


IT depends on which way you flip ball mount (insert)... Or what trailer site you are looking on or what manufacturers name you are searching out...

Beside plus/minus 1 inch is not going to make a whole lot of difference.....

Dale

[G-force]

Your trailer should be slightly down in the front or level, never angled upwards. If your between sizes on the ball mount, go with the one that puts the nose of the trailer slightly low.

[asianflava]

I wouldn't really sweat an inch it will vary on how the trailer and/or how the tow vehicle is loaded. As G-force mentioned, you should have it down rather than up.

[Trackstriper]

Don't mean to hijack, but since we're sort of into this question, why is it recommended to keep the front of the trailer lower? I've heard this recommended before, and prefer it myself, but is there a solid reason to do so other than that some trailers just look goofy with the nose high? Is this to lower the trailer's aerodynamic drag and/or does it have to do with the dynamic stability of the trailer. Does this hold true for an open utility trailer without a body structure? Curious.

Bruce

[Nitetimes]

I don't ever tow with the nose down. If you want to get the tail waggin' that's a sure fire way to do it. On the other hand if you have the front too high it will cause a lot of sway.
I have found and inch or so high in the front is about the best.

[BPFox]

In my experience, trailer movement has more to do with wheelbase and trailer length than anything else. My trailer will be riding high because of the drop frame design where my frame rails in front will only be about 6" off the ground when level. That said, my frame will also be longer than most here and with the axle set back almost 12' from the ball, trailer movement won't be a problem. Under normal conditions, and inch or two is no big deal either way. If you are not happy with the available store bought units you can always build your own. That way, it can be what ever size you want. Peace.

[madjack]

...as close to level as possible...an inch one way or another is not gonna make much difference...WHY??? I have heard everything from aero to bump clearance to swaying...my personal experience would indicate a bit of all three....
madjack

[G-force]

Under braking, especialy trailers with no brakes, all the trailers deacceleration is done by the tow vehicle. As you brake, the trailer is is being pushed into the tow vehicle. If its level, it will push in level. If the trailer is nose high, it will start taking weight off the rear wheels as it raises the coupler assembly. In a panic stop, you can get in the situation where enough weight is lifted off the rear wheels of the tow vehicle and the whole thing jackknifes. Having the trailer level, or slightly downward prevents this. Granted there are alot of other factors like your trailer and tow vehicle wheel bases, how good your brakes and tires are, trailer weight, etc, but when you have a choice to set up a tow vehicle and trailer, why not choose the geometry with the greatest saftey margin.

Mike

Having t

Don't mean to hijack, but since we're sort of into this question, why is it recommended to keep the front of the trailer lower? I've heard this recommended before, and prefer it myself, but is there a solid reason to do so other than that some trailers just look goofy with the nose high? Is this to lower the trailer's aerodynamic drag and/or does it have to do with the dynamic stability of the trailer. Does this hold true for an open utility trailer without a body structure? Curious.

Bruce

[angib]

....why is it recommended to keep the front of the trailer lower?

I believe the reason is that most trailers have a fairly high centre of gravity and it lies fairly close to the axle.

So when you tip them nose-up, the centre of gravity moves backwards quite a bit, reducing the hitch weight and increasing the tendency to sway (actually what it does is reduce the speed at which swaying will start).

I think most of us have experienced with utility or box trailers that if you lift the nose high enough, the centre of gravity moves behind the axle and the trailer wants to tip over backwards. This shows just how sensitive trailers can be to their ride angle.

Andrew

[BPFox]

The big difference here is we are not talking about utility trailers . Most utility trailers have the axle placed near the center so it's pretty easy to get the center of gravity to shift to the point of having a measurable impact on hitch down force. This is not going to be the case with most of the trailers being built here. On many of the builds I am reading about folks are moving the axle back and extending the tongue both of which will improve handing a great deal. The original poster was questioning about a situation where his trailer might be plus or minus one inch from level in the towing position. I doubt seriously if he tried both hitches he would be able to tell the difference in terms of how the trailer pulled.

[brian_bp]

Under braking, especialy trailers with no brakes, all the trailers deacceleration is done by the tow vehicle. As you brake, the trailer is is being pushed into the tow vehicle. If its level, it will push in level. If the trailer is nose high, it will start taking weight off the rear wheels as it raises the coupler assembly. In a panic stop, you can get in the situation where enough weight is lifted off the rear wheels of the tow vehicle and the whole thing jackknifes. Having the trailer level, or slightly downward prevents this...

This doesn't make any sense to me. The effect which is described here is real, but depends only on the ball height - whether the frame of the trailer is level or not is irrelevant.

By this standard, all towing balls should be as low as possible (and there's something to be said for that), regardless of trailer attitude.

[brian_bp]

....why is it recommended to keep the front of the trailer lower?

I believe the reason is that most trailers have a fairly high centre of gravity and it lies fairly close to the axle.

So when you tip them nose-up, the centre of gravity moves backwards quite a bit, reducing the hitch weight and increasing the tendency to sway (actually what it does is reduce the speed at which swaying will start).

I think most of us have experienced with utility or box trailers that if you lift the nose high enough, the centre of gravity moves behind the axle and the trailer wants to tip over backwards. This shows just how sensitive trailers can be to their ride angle.

Andrew

I agree - this is likely the reason for the recommendation. My guess is that most people never check their tongue weight, and tilting the trailer back risks compounding an existing problem.

I also agree with those who suggest that an inch won't likely matter in this case.

[G-force]

Actualy, it depends on the center of gravity of the trailer in relation to the axle (pivot point) and the coupler. Most trailers the CG (up and down, the vertical plane) is above the ball so it indeed usualy pushes down on the bumper of the tow vehicle. But some trailers, usualy utility trailers or boats, with a heavy load close to the pivot point, can get the ball above the CG. I agree, an inch or two probably doesnt matter for 99% of the vehicles and trailer out there. But a lifted 4x4 truck with the ball on the bumper towing a 5x8 utility trailer with a ton and a half of gravel with the nose of the trailer pointed way up is asking for trouble. Remember, we are striving for the safest geometry possable, given the choice of having an ideal situation, or something the "probably is ok", I'll take the former.

Mike

PS: I'm not sure CG is the proper term for what I am trying to say, I mean the center of the mass of the trailer as its mass is deacellerated...I'm sure an engineer can correct my terminology.

Under braking, especialy trailers with no brakes, all the trailers deacceleration is done by the tow vehicle. As you brake, the trailer is is being pushed into the tow vehicle. If its level, it will push in level. If the trailer is nose high, it will start taking weight off the rear wheels as it raises the coupler assembly. In a panic stop, you can get in the situation where enough weight is lifted off the rear wheels of the tow vehicle and the whole thing jackknifes. Having the trailer level, or slightly downward prevents this...

This doesn't make any sense to me. The effect which is described here is real, but depends only on the ball height - whether the frame of the trailer is level or not is irrelevant.

By this standard, all towing balls should be as low as possible (and there's something to be said for that), regardless of trailer attitude.