Weight Distribution & WD Hitches In General

[OnTheGo]

Just thought I would take the WDH discussion up a notch, if it's ok with the OP "OnTheGo".....,

It’s not only ok, it’s welcomed. Your issue is a logical “next step”.

I’m going to try and get a copy of SAE J2807, which might be the catalyst for a "50% rise return". It’s available on SAE’s site, but I’m not willing to pay for it. I’ll also look into Ford’s available technical information.

It might be the industry's way of saying if a certain percentage of the towing population won't apply WD correctly, this is what we'll try to keep them from creating an unsafe situation.

A manufacturer’s statement: “... the front axle weight after weight distribution should not exceed the original weight of the front axle without a trailer.” (Of course that’s one of the issues we just went through.) I think SAE J2807 will introduce most of us to FALR. If you comply with FALR guidelines, you won’t create an unsafe steering / handling situation.

I don’t know if this is correct (it's close), but here comes the short version pertaining to FALR:

Weight on front axle with no trailer = a FALR number of 100

Weight after coupling trailer without WD = a FALR number of 0

After WD the desired weight of the TV’s steer axle would be a return to 100.

An FALR of 50 – 100 is acceptable.

Less than 50 is considered to be insufficient.

More than 100 is considered unacceptable. (Some say dangerous.)

How this translates to wheel-well measurements: Your final front reading should be equal to the starting reading. If not, it's better to be a little higher, never lower.

... here we go again.

[Rustic Eagle]

OnTheGo,

The main reason I brought up the "50%" subject at this time is that it pertains to the basic objective of the WDH adjustment process. The thread to-date has provided a basic understanding of the WDH and it's association to TV/TT weights, and the role of the TV's front suspension in the proper function/adjustment of the WDH.

I also thought by mentioning, and/or discussing the recent Ford & GM "50%" WDH adjustment recommendation at this point in the thread may minimize some confusion in the future as folks reference their TV owners manual on the subject of using a WDH.

It's not my intent to over complicate the subject, but rather maintain the informative theme you have established within the thread.

Bob

[Raugustin]

Hi Bob,

just checked the owners manual for the Ram 1500, they briefly discuss the operation behind the Weight-Distribution Hitch, examples of how the TV/TT combination should look, but go on to say that you should follow the procedures of the WDH manufacturer.

Originally Posted by Rustic Eagle

OnTheGo,

The main reason I brought up the "50%" subject at this time is that it pertains to the basic objective of the WDH adjustment process. The thread to-date has provided a basic understanding of the WDH and it's association to TV/TT weights, and the role of the TV's front suspension in the proper function/adjustment of the WDH.

I also thought by mentioning, and/or discussing the recent Ford & GM "50%" WDH adjustment recommendation at this point in the thread may minimize some confusion in the future as folks reference their TV owners manual on the subject of using a WDH.

It's not my intent to over complicate the subject, but rather maintain the informative theme you have established within the thread.

Bob

[Doug]

I don't know hoe to use 'snip' so I'll just copy and paste.

"It might be the industry's way of saying if a certain percentage of the towing population won't apply WD correctly, this is what we'll try to keep them from creating an unsafe situation.

A manufacturer’s statement: “... the front axle weight after weight distribution should not exceed the original weight of the front axle without a trailer.” (Of course that’s one of the issues we just went through.) I think SAE J2807 will introduce most of us to FALR. If you comply with FALR guidelines, you won’t create an unsafe steering / handling situation."

"How this translates to wheel-well measurements: Your final front reading should be equal to the starting reading. If not, it's better to be a little higher, never lower."

I would think that is a logical assumption and approach by the manufacturuers to help people avoid setting up WDH incorrectly.

Prior to the Internet, most people just relied on the RV dealer and the WDH literature to set up their rigs.

I've not had a loaded out rig and TT for at least 25 years. Back then, I relied on wheel well measurments and followed the literature that came with the WDH.

Never knew about a CAT scale and its availability to the public.

Since that time, I've only owned small popups and never got close to my TV limits.

Maybe we should do a poll to see how many people have used a CAT scale to verify their towing set-up.

Question: Have you ever verified your towing set-up using a CAT scale?

1. Yes - before my 1st trip with my rig

2. Yes - but only recentlty. Owned one or more rigs with WDH and set-up previously only using RV Dealer or WDH literature.

3. Yes - but only after having a serious problem and/or issue.

4. No - have never weighed my rig on a CAT scale. Always relied on RV Dealer and WDH literature. Never had a problem and/or issue related to improper set-up.

5. No - have never weighed my rig on a CAT scale. Always relied on RV Dealer and WDH literature. I have had a problem and/or issue related to improper set-up.

Best regards,
Doug

[OnTheGo]

Bob, I hear you. I said before I like taking a technical adventure, but I understand many people don't. They simply want arrive safely at their destination; nothing wrong with that.

If I get a better understanding than "necessary", I'm OK with that. And if I can present it simply to the forum without everyone having to go down the same road ...

I remember the dealer's rep standing back and eye-balling my hitch setup when I picked up the TT and giving it his approval.
This is not a slam on the dealer, they did a good job with prep - very thorough. But as far as the hitch is concerned, they were getting me home with an unloaded truck and trailer.

I think most dealer reps assume you know you need further adjustment before loading up and taking it out on the road. I didn't. On the other side of the hitch, I have a capable truck (F-150) for my trailer, but I didn't know Ford had a "Payload" option. I wish I had it now.

What I would like to learn and have available on the forum is:

If I want this trailer, how much truck do I need?

Or, if I have this truck, can I haul this trailer? ... safely

What WDH should I buy, and why?

Now that I have the right equipment, how do I set it up?

We can answer some of those things. Probably not all.

The bottom line for me is I don't want to be dependent on someone else for purchasing decisions.


Today, I have a more immediate need - my iPod shot craps. And I like some music in the garage while keeping busy.

[Doug]

On The Go,
I always thought you could setup an Excel sheet getting the 80 for 20.

A format where you enter your data and you get a red, yellow, green result?

Each line could be related to what information you have.

If you don't have the information, you don't get a yellow/red/green response.

Just thinking out loud here.

Doug

[OnTheGo]

Good post, Doug. You posted yours while I was writing my last one. You basically described my situation as well. I didn't know there were CAT Scales.

I was telling an old friend about this thread. He was interested and somewhat concerned. I told him that it was not the problem that it might seem. I think the industry and dealers do have towing under control, but as individuals we can do better. Like all of us, I see many trailers being hauled without issues. Thousands of people get where they're going safely everyday. So, it's too soon to panic.

[OnTheGo]

I always thought you could setup an Excel sheet ...

That sound like a good idea, but I wouldn't know how.

[Rustic Eagle]

Originally Posted by Raugustin

snip......checked the owners manual for the Ram 1500, ....snip..... go on to say that you should follow the procedures of the WDH manufacturer.

Hi Ron,

.. and in all the WDH installation/adjustment instructions that I have seen they state to return the TV's front suspension back to it's "unhitched" height (or weight).

Bob

[Rustic Eagle]

Originally Posted by OnTheGo

snip...... How this translates to wheel-well measurements: Your final front reading should be equal to the starting reading. If not, it's better to be a little higher, never lower ......snip

OnTheGo,

I would have to agree in respect to the TV's front wheel well height, because I know with most full size GM Trucks/SUV's front suspensions if your compress the TV's front suspension below it's unhitched height with the WDH you can bottom out the suspension stops resulting in one rough ride (been there, done it).

It will be interesting to find with the recent "50%" height specification how it relates to "weight return" with the same TV's front suspension, and hopefully it's a simple manufactures clarification that can be applied easily.

Look forward to hearing what you find ......, I plan to make some outside inquires as well.

Bob

[amabee]

That's certainly an interesting change by GM, I also noticed the weight carrying hitch weight went up from 600 to 800lbs. Maybe its just me, but that seems like a LOT of weight on the hitch of a 1/2 ton pickup. Did they do something to the rear suspension? I know during my CAT scale weigh, the 620lbs dropped the back of my pickup a lot, I didn't really drive anywhere of course, but I would have to believe you would feel the steering loosen up. Also not sure about the 7000lb trailer before needing a WDH, at that point you'd be getting very close to the GCWR.

I'll be watching this thread to see what you find out.

[Rustic Eagle]

GM 2013 1500/2500/3500 WDH specifications in detail:

Ok, I found a "little" more detail on GM's 2013 1500 Series Silverado's "50%" WDH specifications, and the 2500/3500 series as well (Data source: http://www.chevrolet.com/owners/chevy-manuals.html)

Vehicle Series: 1500
Trailer Weight: Up to 7000 lbs
WDH Usage: Optional
Hitch Distribution: Refer to trailer manufacturer's recommendation

Vehicle Series: 1500
Trailer Weight: 7001 to 9900 lbs
WDH Usage: Required
Hitch Distribution: 50%

Vehicle Series: 1500
Trailer Weight: Over 9900 lbs
WDH Usage: Required
Hitch Distribution: 100%

Vehicle Series: 2500/3500
Trailer Weight: Up to 18000 lbs
WDH Usage: Optional
Hitch Distribution: Refer to trailer manufacturer's recommendation

The "Hitch Distribution" above is referring to the TV's front fender height (no mention of weight). I have no idea why GM would state "Refer to trailer manufacturer's recommendation", because I have never seen any RV Manufacture recommend any TV front suspension WDH distribution recommendations....., WDH Manufacturer's yes.

The GM 2013 Owners Manual still states 10% to 15% loaded tongue weight (of TT GVW).

Unless I'm missing something, IMO GM has created a lot of confusion in respect to their WDH recommendations

FORD 2013 150/250/350/450/550 WDH specifications in detail:

The following reflects the 2013 FORD 150/250/350/450/550 Series "50%" WDH specifications as stated in their owners manual (Data source: http://owner.ford.com/servlet/Conten...rd&model=F-150 & http://owner.ford.com/servlet/Conten...rd&model=F-250):

"When hooking-up a trailer using a weight-distributing hitch, always use
the following procedure:
1. Park the loaded vehicle (without the trailer) on a level surface.
2. Measure the height to the top of the vehicle front wheel opening on
the fender, this is H1.
3. Securely attach the loaded trailer to the vehicle without the
weight-distributing bars connected.
4. Measure the height to the top of the vehicle front wheel opening on
the fender a second time, this is H2.
5. Install and adjust the tension in the weight-distributing bars so that
the height of the vehicle’s front wheel opening on the fender is
approximately halfway between H1 and H2."

No mention of front suspension weight......, and the FORD 2013 Owners Manual still states 10% to 15% loaded tongue weight (of TT GVW).


I'm still digging.....

Bob

[OnTheGo]

Bob,

You are a step ahead of me with your post containing Ford’s WDH instructions. That information is verbatim from my 2012 F-150 manual, page 276. I called Ford’s information line and the rep referred my question (about 50% return) to technical and assigned it a case number. In the past, I have received good information using their system. It usually takes several days to get a response.

I found this link on a VW site: http://www.clubtouareg.com/forums/f6...n-34061-5.html Scroll down and there are some insights into SAE J2807.

I have an email out to my WDH manufacturer asking for insights. Their response will most likely be a recommendation to follow their instructions, and an unwillingness to speak for the TV manufacturers.

... some thoughts:

have there been front end / suspension changes (or anything else) to make a 50% return desirable

what, if anything, is wrong with a 100% return

TV customers must have asked builders to be able to place heavier loads on rear – are there tension / structure issues with a 100% return

anyone that’s ever driven loaded with roofing shingles, or any other overload, realizes the comfort level and safety of a 100% return

[OnTheGo]

amabee, you're making me remember the ease of hitching up the popup.

Also not sure about the 7000lb trailer before needing a WDH

7000 lbs is two fully loaded x17Z's, and we only haul one.

[Rustic Eagle]

Originally Posted by OnTheGo

snip..... I found this link on a VW site: http://www.clubtouareg.com/forums/f6...n-34061-5.html Scroll down and there are some insights into SAE J2807......snip

Interesting read to say the least.., and even after filtering out the VW Tauareg references within the information presented I got the impression that the author was still in the "interpretation" mode with the approved SAE J2807 standard.

For JOF reader clarification:

What is SAE J2807: An SAE trailer rating committee, with input form the American and Japanese Automotive Industries, was looking to create a "standard/practice" that all Automotive Manufactures would abide by in determining specific Weight Limits (ie; GCWR, Tow Ratings, etc.) thus making it easier to compare one vehicle to another (level playing field). The new practice identified as "SAE J2807" was approved in 2008 by American/Japanese Auto Manufactures, and was given an implementation date of model year 2013.

What is FALR: Front Axle Load Restoration

Originally Posted by OnTheGo

snip..... are there tension / structure issues with a 100% return....snip

I have not seen any evidence to-date even implying that, and I would believe that there would be a strong warning statement within ones owner's manual as well. Heck, it may be even something as simple as the TV manufacturer's opening up the FALR tolerance range W/WO WDH in use (could this be playing into the marketing of the latest Tow Rating wars somehow ???).

I'm curious to hear what your Ford information line inquire produces.

Bob

[Rustic Eagle]

Our discussion thus far has been focused around the Ford and GM "50%" WDH front axle restoration statements.., but it appears that the SAE vehicle test results generated in support of the SAE J2807 standards may also be influencing WDH manufactures. WDH manufacture "Equal-i-zer" brand has revised it's installation instructions to read:

"Good adjustment:

You have most likely achieved good weight distribution adjustment if your
measurements show the following with the trailer coupled and the weight
distribution engaged:

1. From the coupled without weight distribution measurement, the front
wheel well measurement is at least halfway back to the original uncoupled
measurement. See line C on Front Wheel Well Measure Chart.

2. The rear wheel well measurement is somewhere between the uncoupled
height, and the coupled with no weight distribution height. It should
NEVER be higher than the uncoupled height"

Data source, page 18: http://www.equalizerhitch.com/pdf/eq...anual_0111.pdf

IMO it simply means that the TV's front suspension with the Equal-i-zer WDH should be restored to at LEAST 50% and a maximum (100%) of it's original unhitched height.

One obvious observation is the importance (which we have been aware of) of not dropping the TV's front suspension below it's unhitched height with the WDH, and the SAE J2807 standard supports this conclusion. IMO this would also rule out achieving "equal squat" with most TV's.

At a minimum this may provide a little more credibility that 100% front TV suspension restoration is still alive and well.

Now back to the 50% ........................

Bob

Additional source material: http://www.rv.net/FORUMS/index.cfm/f...4.cfm#26670734

[OnTheGo]

When the dust settles on this issue, it's going to take some real convincing numbers to sway me to accept that 100% is not the desired result, with 50% being the minimum.

I still haven't had any responses.

[David472]

When we picked up our first TT, the JayFlight 22FB, the trailer dealer setup our WDH and I merrily went on my way. Later, I did measurements of the wheel well heights with and without the WDH. I discovered the setup was for about 50% return of the front wheel well height. When driving this combination at 60 mph highway speeds, the steering response was too "light" for my liking. I made adjustments to the WDH to bring the FALR to about 95% (a guesstimate). The CAT scale showed all but 50 lbs was returned to the front axle. This made the highway steering response much more to my liking. You will never convince me that 50% FALR is acceptable. Just my 2 cents worth.

I would add, don't worry about the rear wheel well height. Put all your attention on the front axle load with and without the WDH. That's what will determine your stability on the road. Shoot for near 100% FALR.

[Doug]

X2

[OnTheGo]

This made the highway steering response much more to my liking. You will never convince me that 50% FALR is acceptable. Just my 2 cents worth.

I guess you, like the rest of us interested in this issue, will watch it play out.