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dkottum · 03-14-2010, 05:13 PM

Hi Vern. We sure don't need more hitchin' tales.

But don't you have to compress the front springs to bring the truck to level? Stiffer springs, more resistance, more w.d. tension.

If not I will surely edit that line out of my post.

Thanks Vern, and I enjoy the thoughtful discussion.

Doug K

overlander63 · 03-14-2010, 05:42 PM

Quote:

Originally Posted by r carl

Im sure a 1974 frame is only a 4" channel. The 1998 is at least a 5" so be carefull comparing.

Our '74 has a 5" channel. I know, I had to cut part of it out and replace it.
I can post pictures and copies of the receipts for the materials.

r carl · 03-14-2010, 05:48 PM

Im glad i didnt bet on that, you would be

. I thought it was the early 80s when they went to 5".

overlander63 · 03-14-2010, 05:51 PM

Quote:

Originally Posted by r carl

Im glad i didnt bet on that, you would be

. I thought it was the early 80s when they went to 5".

No, it was 4" through most of the '60's. What did change was 5" C channel to 5" box channel in the mid '80's. However, if anything, the C channel would be weaker, and more subject to flex and damage, than the newer box channel. Our trailer does weigh in at a tick over 7500 pounds, fully loaded.

Ag&Au · 03-14-2010, 06:14 PM

Quote:

Originally Posted by dkottum

Hi Vern. We sure don't need more hitchin' tales.

But don't you have to compress the front springs to bring the truck to level? Stiffer springs, more resistance, more w.d. tension.

If not I will surely edit that line out of my post.

Thanks Vern, and I enjoy the thoughtful discussion.

Doug K

After thinking about it, here what I came up with:

It depends on what your goal is in transferring weight. If your goal is just to transfer a certain number of pounds, then the spring strength does not matter. If your goal is to level the truck without regard to how much weight is transferred, then the spring tension comes into play.

Which brings up the question: Which should be the goal?

Regards,

Ken

2airishuman · 03-14-2010, 07:00 PM

Quote:

Originally Posted by w7ts

... Which should be the goal?...

the answer depends on which gizmo is referenced...

1. w/d bars RESTORE steering axle loads (the term equalizing is kitchen swill when used in reference to w/d bars)

2. the shank/stinger/ball mount DROP/distance is used to level the trailer (after the w/d are tensioned).

3. the hitch apparatus ties tv2trailer and SOME of them include sway dampening or sway elimination

4. pig tail transmits juice 4 battery and lights

5. chains and breakaway/brake wire are 2nd safety features IF the primary connection fails.
____________

so AGAIN, primary goal of w/d bars is to RESTORE steering axle load.

all the other real/imaginary objectives 4 w/d bars are 2ndary and vary from rig2rig

"leveling" the truck is NOT a goal of w/d, but may be a CONSEQUENCE on some trucks, sometimes.

1. the truck may not have been "level" unhitched, most are NOT.

2. a tad more DROP on the drive axle of REAL trucks is ok, especially when the axle RATINGs favor the rear.

like most newer mopar trucks.

my truck is 3-5 inches HIGHER at the rear unhitched and only 1-2 inches higher after CORRECT w/d bar tensioning.

but "level" isn't part of the equation, or my rigging goals except for the trailer.

rear axle is only 100 lbs higher capacity compared to the front on my truck (6000/6100),

even with the heavy diesel engine up front.

on SOME trucks this ft/r axle capacity difference is 1-4 THOUSAND lbs

and on those trucks much LESS (or none) w/d is needed...

since the steering axle may not UNload with towing (these trucks typically have a LARGE payload) .

3. REstoring steering axle loads doesn't = compressing the front springs.

w/d is NOT about 'squatting' the truck at all corners (see the primary goal)

4. IF the headlights are pointed upwards while towing that's a CLUE to improperly adjusted w/d gear OR tires pressures...

and a minor issue... IF the front axle load has been restored correctly...

almost no truck with properly adjusted w/d gear will need the headlights adjusted...
____________

5. LEVELING the trailer matters but is largely dictated by DROP on the shank/stinger gizmo...

one can ~ these adjustments with a measuring STICK and many readings...

but weights at the various TENSIONs on the w/d bars are the gold standard.
___________

this thread USED 2b a sticky, and except for the lame jokes about UNDERSTANDING it or math issues...

it's a USEFUL thread on things related.

i have no idea why it isn't now a sticky,

especially considering some the CRAP threads that are stickies in other subforums...

it DOES explain some of these issues without regard to brands of ANYTHING...

http://www.airforums.com/forums/f464...sis-19236.html

maybe that's why it's no longer a sticky?

cheers
2air'

ROBERT CROSS · 03-14-2010, 07:34 PM

Restoring front axle weight/load is the goal, our Burb is not level whether towing or not.

At the CAT..
no bars, str axle 3140...drive axle 5280...trlr axles 7580
WD bars set, trlr level, str axle 3540...drive axle 4900...trlr axles 7680

....it's the trailer that MUST be level.

2airishuman · 03-14-2010, 08:19 PM

one more string of notions...

Quote:

Originally Posted by HiHoAgRV

...Does anyone have some background to the often quoted info that the vehicles spring stiffness has anything to do with transfering weight when using WD bars?

I've drawn some free body diagrams and the only items I see that come into play are distances (ball to axles), bar length and bar tension.

Mees thinkin we have another old hitchin tale on our hands...

i agree with vernon on this point but can't sort out HOW to rectify it in the only brain at my disposal.

in nick's thread i suggested spring rates/tire pressures and cog may alter the math slightly...

but over the last 4-5 years THINKING about this, i dunno anymore.

i suspect the math/equations would be made more complicated to account for those issues (spring rates/tire pressures/cog)...

and only result in MINORly different results compared to the original length/weight equations...

this is way over my pay grade, so someone with real math/engineering skills would need to sort this out for us.

ultimately using scale readings and altering equipment ONE PIECE at a time is the best/pragmatic approach,

while the equations explain WHY and what is happening...
___________

and last, lastly to the O.P....

AVOID or question ALL of the bs/myths/oldtimertales and so on promoted here.

anyone preaching HOW to rig as a declared authority

needs to be able and WILLING to support every step in their approach...

when sensible folks QUESTION those recommendations...

don't buy into any bodies NONsense

if they aren't willing to offer up the basic science/math/engingeering that supports those recommendations.

ok, i'm outta my mind now...

cheers
2air'

jmtandem · 03-14-2010, 08:51 PM

2air,

Interesting comments about heavy diesel engines especially on pickups. Here you preach it that the truck in that configuration may not need much if any WD, but on that other thread when I suggested the same you (tried to) discredit me. Amazing. Maybe you saw the 'light', maybe you just say things. I do agree with you about rear end light trucks being higher and that settling some of that actually causes a truck to ride like a truck is built to ride, more level. That is why I am not a believer in the common measuring of wheel wheels to ground front and rear and then trying to get back there after hitching the trailer that is so common in the instructions of most hitches. Let the rear settle, let it ride more level, let it carry the weights on the rear axle that it was designed to do. It actually works better than empty as to handling of the truck.

Ag&Au · 03-14-2010, 09:13 PM

Quote:

Originally Posted by jmtandem

2air,

................................................
That is why I am not a believer in the common measuring of wheel wheels to ground front and rear and then trying to get back there after hitching the trailer that is so common in the instructions of most hitches. Let the rear settle, let it ride more level, let it carry the weights on the rear axle that it was designed to do. It actually works better than empty as to handling of the truck.

The Equal-i-zer hitch i used to have said to do that. However here is what I have always done. My truck rides a$$ high when empty. It makes sense to me that it was designed to ride level when loaded. When I hitch up with WD bars slack, the back end is low. I tension the WD bars until the truck is level ( rear and front fender wells equal height above ground. (The first time I did it, I adjusted the drop down on the hitch bar to level the trailer).

Regards,
Ken

Aquabud · 03-14-2010, 09:13 PM

My gosh. It seems incredible that a straight answer can't be found for all this.

You'd think an AS engineer would be able to help hear...or someone from HH or PP.

Geez.

Ag&Au · 03-14-2010, 09:20 PM

Quote:

Originally Posted by Aquabud

My gosh. It seems incredible that a straight answer can't be found for all this.

You'd think an AS engineer would be able to help hear...or someone from HH or PP.

Geez.

I would also think that one of those sources would be able and willing to help. That is why I am always amused* when people who want an answer come here first. Especially if they have read some of the previous threads and see where they all go.

By amused, I don't mean laughing at them. I am just chuckling, because I know where the discussion is going to go. I bet I could almost write the script.

Regards,
Ken

jmtandem · 03-14-2010, 09:52 PM

W7ts,

Agreed. I found the same thing with my Equalizer hitch. I have 1200 bars and only tension to level or almost level. Works perfectly without all the measuring stuff. I raised this issue with Progress Mfg. (the makers of the Equalizer hitch) and asked them why they did not specify tension values measured by holes in the L bar under tension or some other measure instead of measuring front/rear before/after stuff. No reply. As more and more tow with diesels it will become an issue as there is no way that some of the tongue weight should be added to the already very heavy front axle on a diesel pickup. And for most pickups the axle bias is way different front/rear empty so adding tongue weight to the rear axle is good. Adding some to the TT axles is probably good, too. Some folks have vehemently disagreed with me often citing one method fits all manufacturer's instructions that cover everything from one ton trucks to Tundras and Explorers. One method of dialing in the hitch doesn't work for all vehicles. On hitches like the Equalizer there has to be some tension for the sway to work. The sway will work less if tension is less, not at all if tension is basically not at all, so I think it would be a very valid question to get answered by the manufacturer as to how much tension is needed for their sway to function. As I have used the hitch, I am becomming less and less of a believer that the Equalizer is really a significant sway mitigation hitch. Very little friction is in the L brackets so it all has to be mitigated in the sockets. I am not real sure about sway mitigation advertising vs reality.

2airishuman · 03-14-2010, 09:58 PM

Quote:

Originally Posted by Aquabud

My gosh. It seems incredible that a straight answer can't be found for all this...

'bud...

IF u dig around there actually are "straight" answers posted here on several hitches DIRECTLY by the hitch makers and their staff...

in particular the EQ' brand has provided some very clear answers here on bar selection and hitch rating choices.

very specific.

haha and pp have also done that.

but once those VERY specific recommendations have been offered (i can provide the links if u need them)

someone comes along with a "yes butt" or objection that really doesn't apply...

or a hugely ODD rig combination...

or tries to destroy the hitch makers advice by suggesting "airstreams are different"...

so there's NOT much point in the vendors REPEATING their advice in several threads.

also they've got their OWN forums and might do that on their OWN websites.

Quote:

Originally Posted by jmtandem

...Interesting comments about heavy diesel engines especially on pickups...

'tandem u must be reading another thread

because there's nothing in my post suggests ANYTHING about the "heavy diesel engine" impacting hitch or w/d bar selection.

and the thread u make reference to is linked below

http://www.airforums.com/forums/f463...ngs-60922.html

i stand by the comments there,

and leave to others who wanna WASTE TIME to read the silliness and decide 4 themselves.

the truck YOU reference is a 1 ton, 6 wheel thing and with a smaller trailer.

it is NOT the topic of this thread...

cheers
2air'

dkottum · 03-14-2010, 10:26 PM

Ken,

Your script outline may include an honest inquiry, honest opinions and experience, seat-of-the-pants opinions based on experience, surefooted opinions and arrogance, argument, and ridicule and cartoons.

It remains unclear why some Airstreams are incurring damage, and others are not.

Little opportunity for discussion.

The original poster is astonished and bewildered after a couple hundred entries.

overlander63 · 03-14-2010, 10:29 PM

Quote:

Originally Posted by Aquabud

My gosh. It seems incredible that a straight answer can't be found for all this.

You'd think an AS engineer would be able to help hear...or someone from HH or PP.

Geez.

A lot of the smoke and mirrors is because of product liability concerns. Nobody dares give a straight answer, because somebody will use that info. and there will be a problem, and the lawyers will come 'calling.

The nearest thing you'll probably get is the "you can handle up to a 1000 pound tongue weight with this setup" statement from some of the WD manufacturers.
If it weren't for the litigious society in which we live, many manufacturers would be happy to give you their best recommendations.

And I'm sure the above is one of the answers given in many of these same threads...

Secguru · 03-15-2010, 01:57 AM

I really appreciate all the thoughtful replies.

The thread http://www.airforums.com/forums/f463...ngs-60922.html is absolutely worth reading on this subject. Thanks so much 2Air for the link.

I understand the physics much better now and the correct process as:
- Test drive unloaded TV and pay attention to steering and front end control
- Weigh unloaded TV front and rear axles
- Weigh loaded AS tongue and wheel weight (sans the TV)
- Attach AS to TV and re-weigh front and rear axles
- Test drive TV with AS attached before adding WD tension and pay attention to steering and front end control
- Add WD tension as required to restore lost weight to front end if required to restore steering and front end control
- Do not exceed hitch manufacturer recommendations on WD tension for tongue weight

Would others agree or disagree?

ROBERT CROSS · 03-15-2010, 06:32 AM

Quote:

Originally Posted by Secguru

I really appreciate all the thoughtful replies.

The thread http://www.airforums.com/forums/f463...ngs-60922.html is absolutely worth reading on this subject. Thanks so much 2Air for the link.

I understand the physics much better now and the correct process as:
- Test drive unloaded TV and pay attention to steering and front end control
- Weigh unloaded TV front and rear axles
- Weigh loaded AS tongue and wheel weight (sans the TV)
- Attach AS to TV and re-weigh front and rear axles
- Test drive TV with AS attached before adding WD tension and pay attention to steering and front end control
- Add WD tension as required to restore lost weight to front end if required to restore steering and front end control
- Do not exceed hitch manufacturer recommendations on WD tension for tongue weight

Would others agree or disagree?

Sounds like a workable plan 'ta me.
The road tests to get a feel for a properly set up rig is a good plan....but do it SAFELY away from traffic, may be difficult due to the location of most CAT scales.

One other point....it's most important that the trailer be level while towing.

Stream Safe...

overlander63 · 03-15-2010, 08:18 AM

Go online and look at Google maps of the locations of all the scales in your area, and try to find one that has an isolated access road nearby. We did this with ours, there was a road that went straight out from town for about 3 miles, and there was a county park at that spot with a big parking lot to stop and turn around in.

jmtandem · 03-15-2010, 08:21 AM

2air,

No, I think the thread I was refering to was "Do I need sway". You are leaning toward another thread, but perhaps it also has the same comments by many. As this subject comes up the comments tend to be the same. Andy on one hand working thru 40 years of issues and problems with Airstreams and those on the other that think it best to just use the hitch manufacturer's recommendations. Even Sean to my knowledge has not weighed in on this lesser spring bar issue for heavier duty trucks and he is pretty good about sharing info as appropriate. Everybody has their lawyers telling them what not to say in case that advise comes back to bite them.