equalizer hitch setup

[retrocar66]

I have a reese WD hitch with 800# bars. I'm setting it up with a new TV, a 2009 Lexus GX470.

Per the advice in these forums, I measured the TV wheel well height unloaded. Then measured again with the trailer hooked up.

With the trailer on, I got no change on the rear wheel well height, but lost 3/4" in the front.

Does this mean I need to take some weight off the bars? I don't have any more chain on them, so this means I'd need to change the hitch ball angle (bring it forward.)

Or is this kind of measurement within bounds of "normal?" This TV does have a rear air suspension, and I could hear it turn on after I lowered the trailer onto the hitch ball. It did this without the key in the car, so I don't think there's a way to turn it off. I'm wondering whether the Lexus is compensating for the tongue weight by raising the rear suspension, and if so whether this matters for the hitch setup.

Thanks!

[Gene]

The title of your thread is "equalizer hitch setup", but the Equalizer is a different hitch than the Reese. Since your question is about the Reese, maybe you should contact a moderator about changing the name.

I have seen questions about vehicles with air suspension and never paid much attention because I don't have it. Do a search on air suspension and you may find the answer. Or you could pull the fuse on the air suspension system and see what happens, but that seems questionable.

Gene

[retrocar66]

Gene, thanks for the response. Sorry for the confusion, I meant "equalizer" in the generic sense of weight distribution. I forgot it was a brand as well.

Per Andy's instructions in this thread I got the following weight measurements:

1. The tow vehicle front axle weight, without the trailer: 2660lb
2. The tow vehicle rear axle weight, without the trailer: 2440
3. The front axle weight of the tow vehicle, with the trailer attached: 3040
4. The rear axle weight of the tow vehicle, with the trailer attached: 2580
5. The trailer axle or axles weight while attached to the tow vehicle: 4320

So I've got 140lb added to the rear axle and 380lb, or over 70% of the tongue weight, to the front.

I cannot loosen the bars any more -- they're already at the end of the chain. The ball is tilted a little -- should I reduce that tilt, i.e. make the hitch ball more vertical? The rig "looks right" to me, in the sense that everything seems pretty level, the bars are slightly bent and parallel to the trailer frame, etc. But the weight distribution seems wrong. Is there something else I should check or change?

I'm going to try to attach a couple photos of the setup this evening in case that elucidates anything.

[retrocar66]

Here are a couple of photos of the current setup.

[retrocar66]

I'm wondering whether the bars are too heavy. Are 800# bars too heavy for a tongue weight of 520lb? That is the empty weight. I expect it to be a little heavier loaded, but I haven't been able to load it yet so I don't know.

[Gene]

Not having a Reese, I can only speak generally—but the most important thing is that the trailer is level. You can't be sure by eyeballing it. Use the longest level you (or a neighbor has) and hold it to the belt line. But you have to be on a level surface and you can check that with a level too.

Paved areas are not perfectly level because they have a small slope to allow rain runoff and because humans made them. The tow vehicle won't be level unless you are really lucky, but by measuring the top of the wheel wells unloaded and loaded you can see how far off you are. In fact right and left sides of the TV will probably be different, but don't overthink this and stay on one side.

When you load the TV, the back will dip down and the front will come up; when you adjust the hitch, you are putting more load on the front and you want front and back to come fairly close to each other. It won't be perfect and should be within an inch of each other. If it is too high in the front, your headlights will light the sky. Closer is great, not easily attained. On an Equalizer, the bars should be level, but that is least important of the three and even harder to do.

I expect all hitches have the same needs of levelness and some, maybe all, companies copy one another in design. The point of a weight distributing hitch is to lock onto the TV frame and shift weight forward to the front axle. It can be done various ways—chains or no chains or shifting the pivot point forward like a Hensley or ProPride.

It is good you are trying to figure this out yourself because dealers don't often do a good job. You have to change the adjustment from time to time as parts wear, but after a while you can forget it for a long time. A good adjustment can take a long time and be tiring—the parts are heavy and having done it under a blazing sun, I can assure you it wears you out. Once you figure it out, you always have a good idea what to do when you have to. Once you get it right, the trailer will tow noticeably better (unless it was good beforehand).

[You posted the photos after I wrote the above. The trailer looks good and I guess you don't have a beltline. The TV looks low at the front, but maybe the pavement is uneven. Hard to tell because the TV may create an illusion of unlevelness. Sheet metal design can be deceiving but measuring the wheel wells is more accurate.]

Gene

[Ron Gratz]

Originally Posted by retrocar66

1. The tow vehicle front axle weight, without the trailer: 2660lb
2. The tow vehicle rear axle weight, without the trailer: 2440
3. The front axle weight of the tow vehicle, with the trailer attached: 3040
4. The rear axle weight of the tow vehicle, with the trailer attached: 2580
5. The trailer axle or axles weight while attached to the tow vehicle: 4320

So I've got 140lb added to the rear axle and 380lb, or over 70% of the tongue weight, to the front.

I cannot loosen the bars any more -- they're already at the end of the chain. The ball is tilted a little -- should I reduce that tilt, i.e. make the hitch ball more vertical? The rig "looks right" to me, in the sense that everything seems pretty level, the bars are slightly bent and parallel to the trailer frame, etc. But the weight distribution seems wrong. Is there something else I should check or change?

Page 185 of the online 2009 Lexus GX470 User's Manual states:

"If using a weight distributing hitch when towing, keep your vehicle level with the ground."

Since your vehicle has rear height control, the rear height will be kept close to its unhitched height.
This means that, to keep the vehicle level, you must adjust the WDH so the front remains close to its unhitched height.
That implies the WDH must be adjusted to return the front axle to its unhitched load.
With your air suspension, this might require a trial and error approach.

Your scales data indicate you've added 380# to the front axle. The front axle load change should be close to zero.
You need to find a way to reduce the amount of load transfer -- either add some chain links, or reduce the amount of rearward tilt of the hitch head.

Ron

[Msmoto]

All sounds like good advice....changing the hitch ball angle forward may be best. Then when set up, ending with front and rear TV axle weights the same vis chain adjustment would keep the tire loads at a minimum on your TV.

In fact, I am readjusting my set up precisely this way to bring TV weights equal front and rear.


Ms Tommie Lauer
Greensboro, NC
2015 Serenity 30 RB / 2008 Dodge Cummins 4 X 4
WBCCI #4165 AIR #31871

[slowmover]

Originally Posted by Msmoto

All sounds like good advice....changing the hitch ball angle forward may be best. Then when set up, ending with front and rear TV axle weights the same vis chain adjustment would keep the tire loads at a minimum on your TV.

In fact, I am readjusting my set up precisely this way to bring TV weights equal front and rear.


Ms Tommie Lauer
Greensboro, NC
2015 Serenity 30 RB / 2008 Dodge Cummins 4 X 4
WBCCI #4165 AIR #31871

No. Steer Axle near to solo weight, not over. And Drive Axle where ever it falls plus a few percent.

This is so however one loads the truck prior to hitching and applying WD. Drive Axle needs to be heavier.

Put the effort into TV tire pressures. With TT tires at max sidewall pressure. Weigh each wheel position. Stay within OEM guidelines plus maybe 5%. Test pressure rise from cold after two hours steady state driving for less than 10% rise. Adjust for lowest TV pressures under noted conditions and then move up, some, in subsequent testing. Maintaining close to factory understeer means less than 100% FALR. And tires at the lower end of pressure.

I keep my 2WD CTD at 7,950-lbs solo. 1220 pounds above empty. 40-lbs difference at all four corners. I expect to see WD numbers overlain, NOT corrected by a different loading.

As I run the roads at 58-mph I am willing to experiment against oversteer problems somewhat. We're yours mine I'd do the following:

On a 4WD Dodge, larger FF/RR Helwig antiroll bars, rear Panhard Rod and KONI FSD shocks. Go to latest revised steering gearbox update.

Dead recirc ball steering is the real problem. With the best numerical or formulaic baseline this is the thing to chase afterwards.

Ball joint and Rod end play are the other 4WD problems. Tire choice is what will be the icing on the cake as transient response is about trailer, not truck, turn in. See too much TV tire pressure and not enough TT pressure around here. It is the wrong direction.

A ProPride if you don't have one. No other hitch type can have the TT react as quickly.

[retrocar66]

Originally Posted by Ron Gratz

Your scales data indicate you've added 380# to the front axle. The front axle load change should be close to zero.
You need to find a way to reduce the amount of load transfer -- either add some chain links, or reduce the amount of rearward tilt of the hitch head.

Ron

Ron - your comment confuses me, because I thought the idea of the WD hitch was to transfer some weight to the front axle. Is that incorrect? If so I have been conceptualizing this wrong. Is it possible to use spring bars without transferring some weight to the front axle? Because if they remove weight from the rear axle, it seems like at least some of it would end up in the front (and some on the TT axles.) But I have also seen some people say that it's the hitch head angle that transfers the weight forward. When I read your comment I realize I'm not sure how this works.

I have also been working under the assumption that a 50/50 load split between the TV axles is ideal. But if I read you right, you're saying that the TV front axle should receive no weight from the hitch.

At any rate I'm going to reduce the hitch head angle as you say, then weigh again and see what I get. I'll post the results here. Thanks for the detailed response.

[paiceman]

You've got a leveling system on the Lexus, I am guessing you've turned that system off when hooking up and towing. We used to tow with the same vehicle and it would level itself no matter what weight we put on the ball.

[retrocar66]

@paiceman I don't think there's a way to turn off the leveling on the Lexus? At any rate I can't find anything about that in the owner's manual. It's off while I'm hitching up, since the ignition is off. But as soon as I start the truck, it lifts the back end up.

I adjusted the hitch head forward by a few degrees, and now with the bars at the last link on the chain (i.e., no loose links) I have the front axle load down to 60 lb over solo weight. The rear axle is taking all the rest of it. The front wheel well is exactly at the height it is before hitching up.

My only concern now is, are the bars loaded enough to function properly? The bars are 800#. I keep wondering if I should go down to 600# bars. There seems to be barely any stress on the bars. There's a little bend in them but it doesn't seem like much. I'm getting some bobbing of the front end of the truck as I tow at 45-50mph, and I wonder whether that's the bars loading and unloading too frequently, due to being too strong.

[Ron Gratz]

Originally Posted by retrocar66

Ron - your comment confuses me, because I thought the idea of the WD hitch was to transfer some weight to the front axle. Is that incorrect?---

The function of the WDH is to add back some or all of the load which was removed from the TV's front axle when the TT was hitched.
For a typical TV/TT combination, hitching the TT with no WD applied might cause a load equal to about 50% of the tongue weight to be removed from the TV's front axle (and cause a load equal to about 150% of TW to be added to the rear).
If the amount of load added back onto the front axle is less than or equal to the removed load, as TV manufacturers recommend, the net load gain on the front axle is negative or zero.
So, yes, the WDH does add load back onto the front axle -- but the load added should not exceed the load removed.

---Is it possible to use spring bars without transferring some weight to the front axle? Because if they remove weight from the rear axle, it seems like at least some of it would end up in the front (and some on the TT axles.)---

Laws of physics cause three simultaneous actions -- load is added to the front axle, load is removed from the rear axle, and load is added to the TT's axle(s).

---But I have also seen some people say that it's the hitch head angle that transfers the weight forward. When I read your comment I realize I'm not sure how this works.---

Actually, it is the downward force exerted on the TT's A-frame by the WDH chains which causes the load transfers.
The downward force is determined by the stiffness and curvature of the WD bars.
The curvature of a bars is determined by the unloaded position of the rear end of the WD bar and by the length of chain under tension.
If you increase the rearward tilt of the WDH head, you lower the rear end of the unloaded bar. This will increase the amount of curvature and bar load if the length of tensioned chain remains constant.
If you keep the amount of head tilt constant and decrease the length of tensioned chain, the curvature and bar load will increase also.

I have also been working under the assumption that a 50/50 load split between the TV axles is ideal. But if I read you right, you're saying that the TV front axle should receive no weight from the hitch.

I'll refer you to this thread for comments on this matter.

Ron

[blkmagikca]

Here is an example of how the weight is distributed.

Last week I was at the Escapade in Tucson AZ and had my AS & TV weighed. The TV was first weighed alone, each wheel on a separate scale, but loaded with my "cargo" (generator and assorted tools and boxes of junque). Then another weight was done with the AS & TV hitched, again with a separate scale under each wheel.

http://www.vsquare.com/howard/photos...smartweigh.pdf

Note that weight measured of each wheel of the TV increased by 200 lbs when hitched. Thus, there is equal distribution of the AS's weight to each wheel of the TV.

As an addendum, this weighing was done with full fresh water, full wash tank & full waste tank (it was at the end of a 5-day rally where I has only water & electric hookups. Note that I am still under the max weight allowed.