goducks10 wrote:
So your saying that a 1/2 ton with a 7200lb GVW that squats 2-1/2" with 900lbs on the hitch is the same as a 1 ton dually with a 14,000lb GVW that squats 1/2" with the same 900lb TW?---
I can't answer your question because I don't know what you mean when you say the 1/2 ton "is the same as" the 1 ton dually.So your saying that a 1/2 ton with a 7200lb GVW that squats 2-1/2" with 900lbs on the hitch is the same as a 1 ton dually with a 14,000lb GVW that squats 1/2" with the same 900lb TW?---
I can say that if the trucks have the same wheelbase and the same ball overhang, the 900# tongue weight will cause the same load to be removed from the front axles and the same load to be added to the rear axles for the two trucks.
If the 1/2 ton squats 2-1/2" and the 1 ton dually squats 1/2" for the same amount of added load, that means the rear suspension for the 1 ton is 5 times as "stiff" as for the 1/2 ton.
If we assume the trucks both have a 150" wheelbase and a 60" ball overhang, the 900# TW will cause about 360# to be removed from the front axles and about 1260# to be added to the rear axles.
For both trucks, the WDH must add 360# back onto the front axle to return the front load/height to the unhitched values.
Quote:
---I just don't see how you would need to put the same tension on the bars/chains to return to the same fender hiegth. If I only needed to bring the front down 1/4" as opposed to 1-1/4" your say it would be the same exact setup on both vehicles. Then why do guys use different settings with their trucks and TT's? Some guys need (Eaz-Lift for example) 4,5,6 washers, some are 1,2 or 3 links hanging.
They use different settings because their trucks and TTs have different wheelbases, ball overhangs, and tongue weights. ---I just don't see how you would need to put the same tension on the bars/chains to return to the same fender hiegth. If I only needed to bring the front down 1/4" as opposed to 1-1/4" your say it would be the same exact setup on both vehicles. Then why do guys use different settings with their trucks and TT's? Some guys need (Eaz-Lift for example) 4,5,6 washers, some are 1,2 or 3 links hanging.
Quote:
I was always under the impression that unless the front of the TV is raised then no weight is being removed. The more the amount it raises the more is removed. Is that right or wrong?
It is correct that the front will not raise or lower if the front axle load does not change.I was always under the impression that unless the front of the TV is raised then no weight is being removed. The more the amount it raises the more is removed. Is that right or wrong?
If load is removed from the front, the front will rise.
The amount of rise depends not only on the amount of load removed but also on the suspension stiffness.
The amount of load which must be added back via the WDH depends only on the amount of load removed by application of TW -- it does not depend on suspension stiffness.
Ron
2004 Ram 3500 2wd Dually
2015 Grand Design Reflection 303RLS
That bushing crush is why have asked for the higher tongued trailers, so they have
a longer ball-shank?
Also, that is what happens to plastic springs that are compressed beyond their travel
rating. Coiled steel springs will just bottom out and no more travel ability.
Plastic or any compliant material springs will continue to be compressed till the material itself fails.
Some might go plastic and extrude themselves out, some might crack, some might
crumble, etc
The cool think about using a plastic spring is that it's stored kinetic energy
is released slowly. So the potential for the WD Hitch System 'bouncing' is much lower.
-Ben Picture of my rig
1996 GMC SLT Suburban 3/4 ton K3500/7.4L/4:1/+150Kmiles orig owner...
1980 Chevy Silverado C10/long bed/"BUILT" 5.7L/3:73/1 ton helper springs/+329Kmiles, bought it from dad...
1998 Mazda B2500 (1/2 ton) pickup, 2nd owner...
Praise Dyno Brake equiped and all have "nose bleed" braking!
Previous trucks/offroaders: 40's Jeep restored in mid 60's / 69 DuneBuggy (approx +1K lb: VW pan/200hpCorvair: eng, cam, dual carb'w velocity stacks'n 18" runners, 4spd transaxle) made myself from ground up / 1970 Toyota FJ40 / 1973 K5 Blazer (2dr Tahoe, 1 ton axles front/rear, +255K miles when sold it)...
Sold the boat (looking for another): Trophy with twin 150's...
51 cylinders in household, what's yours?...
threads (revisit, or something like that). Don't see threads authored
by blocked members. To that one guy who remembered my email posted
a few years ago, please do NOT post/tell anyone...was a big mistake
when I did that
Plus personally like to keep posts with the same topic on as few as
possible threads. As too many dilutes and too often, miss something
germane to the topic
Question was 'can I explain why the Andersen does not distribute enough
weight'
First, before I get dinged again on one of my thoughts that the Andersen
does NOT put weight (and to address that before comments back) that 'weight'
in units of measure is pounds (weight)
Visualize taking any traditional WD Hitch springs (round, trunnion, etc)
and straighten or bend them to point straight down, parallel to the
Ball shank center line.
Then apply a force to the now straightened spring bar end where it
normally has the chains attached
That force pulls that bar end BACK towards the trailer
The resultant torque on the TV Receiver is what lifts (via torque
on the receiver cross tube) the TV's rear end to distribute weight
over to the TV's front axle
Don't know the exact lever arm lengths, but for discussion purposes
use 8 inches from the ball center down to the plate at the bottom of
the Andersen Ball/Shank. Then with the above scenario will have the
traditional bar lever arm around 25 inches. Again, 'or there abouts'
in comparison between a traditional vs Andersen WD Hitch
So if the amount of force is exactly the same between them in this
scenario, the one with the longer lever arm will develop more torque
or WD
Since the Andersen's lever arm is way shorter. The force required
to equal the traditional's lever arm would be much larger
Think of one palm pushing towards the front of the TV, while the other
palm pulling on the bottom of the Andersen ball/shank, or pulling
on the bottom of the hitch head where the spring bars attach to the
WD Hitch head.
BUT the traditional WD Hitch system will not load the coupler
latch assembly as the Andersen does. Traditional WD Hitch will load
the top of the ball, or more precisely have a downward force on the
coupler to ball union. The Andersen push/pulls the tongue towards the
TV, therefore loads the latch assembly
That then develops torque on the line/distance between the ball center
and the end of the lever arm (Andersen bottom plate or traditional WD
hitch spring end)
BTW this is the verbatim quote I got from Andersen when I asked about the pressure put on the rear of the coupler - "The marring of the ball and the pressure applied to the coupler does not concern us as the force is much less than a trailer that is being towed conventionally and every time the brakes are applied the coupler is slammed to a stop on the ball."
I didnt reply to that one as that was also in their reply about something else, but I dont agree with that statement at all. I have never felt my trailer "slamming" into the ball and have never seen wear on the rear of the ball like I do with the Andersen. I have some pretty good and deep wear marks on the ball. I think if your TT brakes are setup correctly there should never be "slamming" into the ball.
2012 FR Surveyor Sport 295
2015 Nissan NVP 3500 SL 5.6L
Tekonsha P3 / "New" Blue Ox Sway Pro
As for the magintude of the force being less, I beg to differ. Unless they have some numbers to back that statement up (which I doubt) it's called an opinion. In my opinion, the force could be very similar. A 3000lb trailer being braked by the tow vehicle at 1g will exert 3000lbs on the 'rear' of the ball. I thought somebody somewhere estimated the chain tension to be in the neighborhood of 2000lbs per chain on the Andersen system IIRC... At any rate, a key difference is that in a 'conventional' or non-braked trailer, that pressure is only in that direction when braking (or when the trailer is pushing the vehicle downhill). On a trailer using an Andersen setup, that pressure is there virtually ALL THE TIME. That's where I've got a problem... Unless they have worked with the coupler manufacturers and dones some long term testing of a variety of couplers for compatibility (which I'm not convinced they did), I would take their claims with a grain of salt.
Ron Gratz wrote:
Class 3 -- 15,000# both forward and rearward
Class 4 -- 3 times trailer GVWR both forward and rearward
I don't know how much forward thrust against the ball will be produced by the Andersen system,
but it probably is considerably less than the VESC/SAE test specification.
Ron
CHD Dad wrote:
Hey guys - since we obviously have some engineers on here, has the coupler/latch issue ever been figured out? I know many pages back there was talk of contacting one of the big coupler manufacturers about it but I dont recall ever seeing a followup to that post. To me that is the single biggest flaw and/or safety issue with the Andersen design. Having the latch fail either while towing or when it comes time to just disconnect would be a major issue!
According to the VESC V-5 Regulation and the SAE J684 Standard -- the longitudinal test load for a ball and coupler is:Hey guys - since we obviously have some engineers on here, has the coupler/latch issue ever been figured out? I know many pages back there was talk of contacting one of the big coupler manufacturers about it but I dont recall ever seeing a followup to that post. To me that is the single biggest flaw and/or safety issue with the Andersen design. Having the latch fail either while towing or when it comes time to just disconnect would be a major issue!
Class 3 -- 15,000# both forward and rearward
Class 4 -- 3 times trailer GVWR both forward and rearward
I don't know how much forward thrust against the ball will be produced by the Andersen system,
but it probably is considerably less than the VESC/SAE test specification.
Ron
OK, I am an engineer. And I've been reading this long thread recently with interest because I'm thinking of buying the Andersen WDH.
I've been thinking about the "reverse stress" concerns on the ball and coupler. Only time will tell, but maybe it's not such a big worry - here's why:
So for a Class 4 ball and coupler, don't the standards quoted above mean they must work up to 3G forces (3 times trailer GVWR)? And this means 3 G's both forward and backward (for accelerating and braking). Especially for extreme braking conditions where the trailer brakes totally fail and the truck brakes must stop the trailer through the ball and coupler. Probably the highest G Forces on the ball and coupler will be while braking with failed trailer brakes.
I doubt any TV can accelerate with a heavy trailer anywhere near 3G's - unless you had a jet engine or rocket or something as you would need 42,000 lbs of thrust from the TV to get 3Gs on a 14,000 lb rig: (6,000 lb TV + 8,000 lb TT) x 3 G's = 42,000 lbs. of thrust through the TV tires to the road to get 3Gs on the ball and coupler. A couple guys on the Tow Vehicles forum might have a mod for this.
![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/cool.gif "cool")
So if you have a 8,000 lb GVWR trailer, the ball and coupler MUST be able to handle 24,000 lbs. of force in either direction (forward or reverse). I think the force on each chain from compressing the bushing for a heavy trailer can be around 1,000 pounds per chain.
This means 2,000 pounds of force (more or less) is applied to the coupler (1,000 lbs. per chain) that is rated for 24,000 pounds of force. This seems like a pretty good safety margin. But again, these are calculations (that I think I got right) - only time will tell for sure.
And over on the Airstream forum, some of them did have issues with their couplers failing with Andersen WDH. I have a theory for why they are seeing that. Basically Airstreams don't rust or rot - there are lots of 30 and 40 year old Airstreams out there with 30 and 40 year old couplers that are probably worn out. But the owners don't know about it till they use the Andersen Hitch.
Ed
I don't know if the Andersen WDH has been certified per the VESC/SAE regulation/standard.
I do know that the standard/regulation states that the specified force level need be maintained only for a maximum of five seconds.
Based on user reports, it is likely that the coupler latching mechanism failures are a result of the steady chain-induced force which acts continually when the Andersen WDH is activated.
That type of loading would not have been simulated in the VESC/SAE tests.
Ron
Ron Gratz wrote:
Ed,
Snip..............Based on user reports, it is likely that the coupler latching mechanism failures are a result of the steady chain-induced force which acts continually when the Andersen WDH is activated.
..........Ron
Ed,
Snip..............Based on user reports, it is likely that the coupler latching mechanism failures are a result of the steady chain-induced force which acts continually when the Andersen WDH is activated.
..........Ron
How many and what kind of failures are they reporting? Dozens? Any particular couplers or all of those used on modern travel trailers? I have an Andersen hitch which I like for being clean, lightweight, easy to use, and resistant to sway, but I do not want to lose my 2012 trailer while going down the road. Has this actually happened to anyone?
"Ben - that all makes perfect sense to me and what I was thinking about when looking the design over after getting my scale numbers. There just isnt enough leverage for the amount of force the chains are applying. It works to a point and then rapidly diminishing returns start happening."
I agree with the leverage statement and that is basically the reason I did not go with the Anderson for my new, heavier trailer I have on order.
I'm NOT an engineer, but I understand basic mechanics and concepts of leverage and weight distribution. I also do not see how the chains pulling on a horizontal plane as they apparently do can apply enough leverage to get the proper weight back on the front tires as compared to what weight distribution bars do.
I agree that the chains do transfer some weight to the front, but not enough for the larger trailers. The Anderson is probably fine for trailers in the 5-6,000 lb range.
2016 6.7 CTD 2500 BIG HORN MEGA CAB
2013 Forest River 3001W Windjammer
Equilizer Hitch
Honda EU2000
"I have this plan to live forever; so far my plan is working"