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Old 10-19-2020, 12:54 PM   #81
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Originally Posted by jaybauman View Post
It appears you mis-typed Steer value for TV+TT (No WDH). Your steer axle should be a lower value after you hook up your trailer with no WD. Should this value be 2840 instead?
Yes I did make a mistake on that one.
And you are correct that it should have been 2840 lbs.
Thx.
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Old 10-19-2020, 02:53 PM   #82
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Originally Posted by BayouBiker View Post
Joey, allowing for the typo mentioned, as it is you are returning a bit more that 50% load to the front axles and that is good result for you.

The last 1/16 does not return nearly as much load as the average of the previous 4/16ths which further indicates flex is absorbing much of the generated torque. I should have mentioned rear tow vehicle and trailer tire pressure as possible sources of excess flex also if the pressure is a bit low and soft rear tow vehicle springs which you can't easily do much about. In any case, you are in the right ballpark as is so you're in pretty good shape.

Q2. You are correct about how to shim the shank and slop in the system does impact weight transfer. The Andersen is much more sensitive to flex and gaps because you only have 1/4 inch of spring movement which translates into about 1 to 1-1/2 inch of ball movement in each direction so if shank fit allows for say 1/8 inch ball movement that absorbs 5-10% of the available tension there alone. Two or three additional gaps can rob you of half your tension. Conventional bars provide for 3-6 inches of ball movement so small gaps are much less noticeable.

Q3. correct again. Just check to see if the ball moves front to back, side to side or up and down in the socket. With your coupler, I am not sure how to adjust it if there is movement.

Q4. Yes, three or more fully welded points between the receiver and mount bar(s). Mine has four. One in front, one in back and two on the top. Then a secure attachment of the bar(s) to frame. Most factory receivers are great but some are not.

Q5. The blackened metal dust and the marking indicates some movement of the ball but it appears to be all in the pitch direction which is expected and will continue until the ball and socket conform to the same exact shape. Pitting, scrapes or metal to metal transfer should not occur.
Thanks for the detailed responses. Appreciated!

Had a few follow-up questions if you don't mind...

Q6: If I stop tuning any further to shift more weight to the Front Axle, what performance issues am I not optimizing and what issues could I observe when towing with my current setup? In terms of shifting weight to the front axle, I had been told about two different targets:
* 50% of difference in weight between TV only (Steer Axle) and TT+TV w/NoWDH (Steer Axle). For me, this would mean aiming for a SteerAxle weight of 2840+150 = 2990lbs.
* 33% of tongue weight should be added back to the Front Axle weight which for me would be 2840+680/3 = 3066 lbs.

If I don't aim for the 2nd one, will be braking be worse? What could I see due to not shifting more of my weight forward?

Q7: In terms of shim'ing the shank, any recommendations on specific products that have proven good?

Q8: In terms of checking for ball movement, I believe I am likely not doing this check correctly as it moves around quite a bit. I simply took the Andersen ball (detached from TV) and placed it into the coupler and latched it.

Q9: The rear suspension on the Expedition is quite soft so this may explain some of my challenge in shifting the weight. There remains visible sag in the rear even after shifting weight to the front. Would replacing the shocks with Bilstein 5100's help? I purchased them but was told to try tuning the towing setup first before considering replacing the shocks. Am also interested in whether products such as sumo springs could help with the shifting of more weight to the front.

Q10: What are the dangers of adjusting the tension to the Urethane springs to the point where they are squeezing beyond the noted amount (i.e. 11 threads causes the spring length to reduce smaller by 1/16" than recommended to 1 11/16")?



Thanks again for all the suggestions!
I'll make sure to keep an eye on my tire pressure as well (i.e. I have monitors and have always tried to keep the pressure ~75-80psi on my RV Endurance tires and ~40 on my TV tires (i.e. Hankook ATM Dynapro's).
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Old 10-19-2020, 04:03 PM   #83
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Great questions! If you fine tune the set up you may find steering more precise with less drift, porpoising reduced, suspension natural frequency more pleasant (roughly the same as a natural walk), and response to passing trucks and large van reduced. It won't alter braking much, and it can improve sway response slightly.

So nothing here that makes a great deal of difference, and it is possible your set-up performs better with less tension than you have currently, though I would be surprised.

The two general rules are more like guidelines intended to get you to the same spot. vehicle geometry (wheel base and hitch overhang differences from the guidance assumptions) accounts for the difference. I shimmed mine with a piece of 1/8 flat stock and hold it in with an anti rattle clamp.

Q8. What you describe is what I did, and initially had a lot of wiggle room like what you are describing. perhaps there is a way to remove that. I posted photos of one step. I will post pictures of the second step in a bit. I don't know how you can remove the wiggle room in your case. Since you are getting enough transfer, it may not be critical to do anything about it, though since I am a bit of a stickler, I would probably try to find a way.

Q9. If the new shocks have helper springs it will make a difference otherwise maybe not so much, though they may reduce the amplitude but not the frequency of porpoising. I find the frequency most annoying.

Q10. If you compress the urethane springs too much beyond 25% of the free length, they will wear out faster. In significant excess, they will split. Now that I think about it, when I distributed over 900, I did not measure total deflection, and I likely was well over the 25% guidance, I suppose I should do that over and report deflection also.
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Old 10-19-2020, 05:19 PM   #84
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Originally Posted by BayouBiker View Post
Great questions! If you fine tune the set up you may find steering more precise with less drift, porpoising reduced, suspension natural frequency more pleasant (roughly the same as a natural walk), and response to passing trucks and large van reduced. It won't alter braking much, and it can improve sway response slightly.

So nothing here that makes a great deal of difference, and it is possible your set-up performs better with less tension than you have currently, though I would be surprised.

The two general rules are more like guidelines intended to get you to the same spot. vehicle geometry (wheel base and hitch overhang differences from the guidance assumptions) accounts for the difference. I shimmed mine with a piece of 1/8 flat stock and hold it in with an anti rattle clamp.

Q8. What you describe is what I did, and initially had a lot of wiggle room like what you are describing. perhaps there is a way to remove that. I posted photos of one step. I will post pictures of the second step in a bit. I don't know how you can remove the wiggle room in your case. Since you are getting enough transfer, it may not be critical to do anything about it, though since I am a bit of a stickler, I would probably try to find a way.

Q9. If the new shocks have helper springs it will make a difference otherwise maybe not so much, though they may reduce the amplitude but not the frequency of porpoising. I find the frequency most annoying.

Q10. If you compress the urethane springs too much beyond 25% of the free length, they will wear out faster. In significant excess, they will split. Now that I think about it, when I distributed over 900, I did not measure total deflection, and I likely was well over the 25% guidance, I suppose I should do that over and report deflection also.
Thanks again for all of your helpful responses!

I'll look into the shim and anti-rattle clamp and probably just take my time to have the shocks installed when convenient...Will have to ponder about how much time to spend on the ball to coupler tuning...For some reason, my wife and kids are not as interested as I am about making the trek to the CAT scales. They've been quite patient with me heading over there 5 times in the last several months...

I thought I would post my data including the slightly looser tension. When I first started trying to tune, I always found looking at people's data useful to get a sense for the #'s...

Thanks again!


=========
DATA
Expedition (TV) Limits:
Payload: 1767 lbs
GVWR: 7720 lbs
Tongue Weight: 900 lbs
GCWR: ~15000 lbs
Front AWR Max: 3550 lbs
Rear AWR Max: 4380 lbs

TV Only:
Steer Axle: 3140
Drive Axle: 3460
Total Axle: 6600

TV+TT (No WDH)
Steer: 2840
Drive: 4440
Trailer: 4880
Total: 12160
Over Rear AWR by 60lbs

TV+TT (9 threads)
Urethane Spring Length: 1 13/16"
Steer: 2920
Drive: 4340
Trailer: 4920
Total: 12180
Allows 40lbs more in TV rear until exceed Rear AWR

TV+TT (10 threads)
Urethane Spring Length: 1 3/4"
Steer: 3000
Drive: 4240
Trailer: 4940
Total: 12180
Allows 140lbs more in TV rear until exceed Rear AWR

TV+TT (11 threads)
Urethane Spring Length: 1 11/16"
Steer: 3020
Drive:4180
Trailer: 4960
Total: 12160
Allows 200lbs more in TV rear until exceed Rear AWR
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Old 10-19-2020, 06:13 PM   #85
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I don't know franklyfrank, your story is interesting and I don't doubt your personal experience, but how can you be sure the problem was a fundamental design limitation of the hitch?

How much resistance to angular velocity is the Andersen is capable of delivering relative to the Blue Ox design do you know?

Zero, Nada.
All you have is compression of urethane rolls and the braking action of the hitch which is a joke. Neither generate counterforce.
Simple to understand. You can pull with a chain but never push. Same with a rope.
The Anderson especially dangerous when the trailer is pushing towards the TV. Going through Colorado with the many downhill runs I was basically crawling towards the end which of course forced every semi to pass me causing even more problems.
I am mechanically inclined and worked with that sucker for almost a full season. Experimented with different lengths of chain and setting combinations..
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Old 10-19-2020, 11:12 PM   #86
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When referring to safety wire, do you have a pointer to an example of what would be good to use? Thx!
I just ordered safety wire from Amazon, nothing special. As a temporary fix on the road, I used a tiewrap just to keep it from unscrewing. Click image for larger version

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Old 10-20-2020, 07:15 AM   #87
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Originally Posted by franklyfrank View Post
Zero, Nada.
All you have is compression of urethane rolls and the braking action of the hitch which is a joke. Neither generate counterforce.
Simple to understand. You can pull with a chain but never push. Same with a rope.
Interesting theory. Traditional shock absorbers don't generate a counter force, yet they work. The Equalizer does not generate a counter force. Wheel brakes don't generate a counter force. The Blue Ox uses a chain and spring to generate tension also. You can't push on the Blue Ox chain either.

The Andersen generates hundreds of ft lbs of angular resistance, just as does the Blue Ox. But the Blue Ox offers no resistance at zero yaw angle, which is not ideal.

Quote:
The Anderson especially dangerous when the trailer is pushing towards the TV. Going through Colorado with the many downhill runs I was basically crawling towards the end which of course forced every semi to pass me causing even more problems.
I am mechanically inclined and worked with that sucker for almost a full season. Experimented with different lengths of chain and setting combinations..
It is unfortunate you had poor experience. Sway tendency is worst on winding steep descents as you discovered. Small amounts of slop and flex in the system can easily rob you of 50% or more of its capability. Conventional WD systems make use of much larger preload distances so slop in the system has about 10-25% of the effect it has on the Andersen hitch. I suppose we could describe this as a negative, but no system does well with slop and it should be completely eliminated.
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Old 10-21-2020, 02:29 PM   #88
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Originally Posted by BayouBiker View Post
Interesting theory. Traditional shock absorbers don't generate a counter force, yet they work. The Equalizer does not generate a counter force. Wheel brakes don't generate a counter force. The Blue Ox uses a chain and spring to generate tension also. You can't push on the Blue Ox chain either.

The Andersen generates hundreds of ft lbs of angular resistance, just as does the Blue Ox. But the Blue Ox offers no resistance at zero yaw angle, which is not ideal.



It is unfortunate you had poor experience. Sway tendency is worst on winding steep descents as you discovered. Small amounts of slop and flex in the system can easily rob you of 50% or more of its capability. Conventional WD systems make use of much larger preload distances so slop in the system has about 10-25% of the effect it has on the Andersen hitch. I suppose we could describe this as a negative, but no system does well with slop and it should be completely eliminated.
You guys are getting way too technical for me. Are you talking about no counter force since it offers CF on pull but obviously you can't push a chain. However, the other side... other chain is being pulled. Isn't that counter force?

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Old 10-22-2020, 09:51 AM   #89
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You guys are getting way too technical for me. Are you talking about no counter force since it offers CF on pull but obviously you can't push a chain. However, the other side... other chain is being pulled. Isn't that counter force?

FE
On the BO there is constant counterforce on both sides in both direction provided by tention on the spring bars.
Essentially the way all good Sway Prevention hitches operate. The chain is pulling up on the spring bars continualy regardless of direction.
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Old 10-22-2020, 11:12 AM   #90
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How Sway Prevention Devices Operate...

My understanding of how sway prevention devices operate is to introduce a dissipative force into the mechanism. The springs and chains are for weight distribution.

Take a standard WD hitch with just chains, you have to add the friction bar to the A-frame to reduce sway.

The Equalizer Hitch provides WD and friction in its design of the bars and the support brackets.

On the Andersen Hitch, the urethane springs operate in compression providing tension on the chains like a standard WD hitch. This is not very dissipative. But put the hitch ball into the shank, and you have a dissipative element. And like on all other sway prevention devices, its always in play.
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Old 10-23-2020, 08:29 AM   #91
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My understanding of how sway prevention devices operate is to introduce a dissipative force into the mechanism. The springs and chains are for weight distribution.

Take a standard WD hitch with just chains, you have to add the friction bar to the A-frame to reduce sway.

The Equalizer Hitch provides WD and friction in its design of the bars and the support brackets.

On the Andersen Hitch, the urethane springs operate in compression providing tension on the chains like a standard WD hitch. This is not very dissipative. But put the hitch ball into the shank, and you have a dissipative element. And like on all other sway prevention devices, its always in play.
Accept when you are going dow hill and notice that the trailer is trying pass you up.
This occured a number times to me and scared the bejeezes out of me. It was than that I realized that thebrake shoe concept in thitch is nonsense. It might work with small light weight trailers but not with AS that have heavy toungue weight.
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Old 10-23-2020, 08:42 AM   #92
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franklyfrank, you may be too quick to put blame on the wrong component. Clearly something was wrong with your setup but it could have been any number of things. If the design was the fundamental issue, then all users would report inadequate sway damping. However I road tested it directly and found it capable of producing significant damping through the range of applied tension. If people are interested enough I can directly measure it and compare it to my Blue Ox.
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Old 10-23-2020, 02:42 PM   #93
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These photos illustrate how I shimmed the fork ramp so the ball fits tightly in the socket with no rattling in any of the three dimensions. the photos uses a thin piece of aluminum for ease but my actual shim is galvanized steel plate stock 0.044 inches thick.

Cut to correct width, leave it long

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closeup of socket, fork and ramp

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Inserted between fork and ramp

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Folded over to keep in place

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Finshed product after towing 1500 miles. I used plate with a slot milled in it so it conforms more easily to the desired shape since it was quite stiff.

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Old 10-23-2020, 03:14 PM   #94
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Since this was labeled "performance testing" do you have any video with the same TV and Trailer with the different hitches including the Andersen on a slalom course designed to induce sway at speed? At what speed did you induce sway and how long did it take to control? It would be more beneficial than antidotal information on sway control and static weight distribution numbers.
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Old 10-23-2020, 03:23 PM   #95
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I didn't take any videos. Slalom courses aren't a good way to objectively test for sway or measure damping, It is more for general handling performance rather than stability and tells you more about the vehicle than the hitch. I did a steering impulse test by snapping the steering wheel rapidly left or right enough to induce significant trailer yaw and then counted the number of oscillations before it was damped out. I did it at 70 mph.
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Old 10-25-2020, 10:35 PM   #96
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I didn't take any videos. Slalom courses aren't a good way to objectively test for sway or measure damping, It is more for general handling performance rather than stability and tells you more about the vehicle than the hitch. I did a steering impulse test by snapping the steering wheel rapidly left or right enough to induce significant trailer yaw and then counted the number of oscillations before it was damped out. I did it at 70 mph.
I trust that you are not suggesting others do likewise - or that would have to the most potentially dangerous 'advise' I've yet seen on a forum.

At speeds like that, there is only a tiny speed margin between the minor oscillations that are being described - and a full-on chaotic jack-knife.

I have done that described professionally but with stabilising outrigger wheels to preclude a total rollover - and the loss of control between the sway Brian describes and irreversible loss of control is sudden.

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Old 10-26-2020, 07:00 AM   #97
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Of course you are correct, Collyn. I don't suggest anyone repeat this test. An impulse test performed randomly without any build up is very risky. I started very slowly and deliberately and proceeded with caution vowing to stop if and when damping dropped significantly. I won't describe the exact process out of caution.
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Old 10-26-2020, 06:55 PM   #98
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Of course you are correct, Collyn. I don't suggest anyone repeat this test. An impulse test performed randomly without any build up is very risky. I started very slowly and deliberately and proceeded with caution vowing to stop if and when damping dropped significantly. I won't describe the exact process out of caution.
The main risk is that, with some rigs (particularly that feel ultra-stable), give next to no warning of incipient instability. In Australia (according to police) the most common comment after a roll-over is that 'it always felt so stable up to them'.

This forum puzzles me at times - in that people buy a very costly travel trailer, then buy (or use) a tow vehicle that is lighter - then seek various ways of easing that. (Friction devices work at low speed but are useless at high speed).

Either buy a lighter (and shorter) Airstream or a longer and heavier tow vehicle. If that is not feasible, drive slower. Your main risk is when descending steep winding hills at speed - and close-passing truck wind gusts.

This is not an issue of 'opinion'. Newton worked out the basics in the 1680s!

So did dog breeders - they probably found that dogs with oversize tails had issues when running!

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Old 10-26-2020, 07:49 PM   #99
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Again your comments are quite appropriate, there are many here who tow long heavy trailers with light short vehicles. Me, not so much. I tow a 7100 lb trailer with a long 9300 lb vehicle. It is quite stable inherently but WD and sway damping improves the ride, handling and steering feel quite a bit. It also has a dramatic reduction of lateral movement in vehicle aerodynamic slip streams and cross winds.
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Old 10-26-2020, 09:15 PM   #100
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TV weight vs TT weight

Is there a rough guideline on how much more should the TV be relative to the TT? My TV (2019 Ford Expy Max, wheel base of 131'') has a weight of 6600 lbs vs the TT (2017 FC 23D) which has a weight of 5580 lbs.

I am within the margins of the various other aspects but wanted to know what would be the impact be of having a TV that is ~1000lbs heavier than the TT...Or is the goal simply to make sure the TV is at least slightly heavier than the TT.



======

Payload is 1287 lbs (vs 1767 lbs available)
Tongue weight is 680 lbs (vs 900 lbs available)
TT is 5580 lbs (vs 6000 lbs GVWR)
TV is 6600 lbs (vs 7720 lbs GVWR)
TV.FrontAxle Weight is 3000 lbs (vs 3550 lbs available)
TV.RearAxle Weight is 4240 lbs (vs 4380 lbs available)
GCWR is 12180 lbs (vs 15500 lbs available)
% Front Axle return with WDH = 53% (160 lbs / 300 lbs)
Front Axle (TV Only) = 3140
Front Axle (TV+TT No WDH) = 2840
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