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New Andersen WD hitch

JBarca
Nomad II
Nomad II
A fellow camper bud showed me this. It's new and different.

Anyone using one?

Andersen WD hitches

A U-tube video with the factory guy explaining it. You have to get past MR Truck doing his intro. Interesting 5th wheel hitch too.

http://www.youtube.com/watch?v=xvM7mCnqmwo&feature=related

It looks like this



I'll hold my comments for a short while to not cloud your thoughts. Ideally we can find someone here using one to quiz them on it.

John
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.
514 REPLIES 514

BenK
Explorer
Explorer
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!


Only time will tell on how the latch(s) last or not.

Not just a couple of trips, but tens of thousands of miles and years
of service. Even then, dependent on the terrain, size of the trailer,
the driving style with lots of etc, etc, etc...

I think the coupler needs to be a custom for an Andersen system. It
should be 'backwards' with the latch in 'front' and the shaped area to
capture the ball in 'back'...or...some how remove the forces on the
latch, which was never designed to handle that level of forces

Again, I still think the Andersen is an elegant architecture, but the
devil is in the details and the latch is only one of those details

Not just unhooking (not being able if that latch comes apart or is
deformed), but during a whoopee-doo where the ball wants to go down
and the coupler wants to go up...the shape of the coupler (front)
captures the ball for this and the latch keeps the ball from moving
backwards OUT of the coupler front capture area...
-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?...

BenK
Explorer
Explorer
Glad you guys got to a common point

Have been PM'd to keep it simple so as to not have to PM me more...those folks
got lost with the last few posts

Years ago during discussions of the GMT800 receiver found that 'consumed' made
sense to the folks talking to and have been using that ever since,
but with highly trained and detailed eyeballs...that is too loosey goosey a term

The last few posts discusses that in detail and here it is baked down in
layman's terms that have worked for me on those PM discussions

All traditional receivers use the cross tube (whether square or round) is a
torque tube.

The Pin Box has the shank and hitch head levered upwards by the WD Hitch system
spring bars (round and trunnion) and on the Andersen system, by the chain

Both imparts a lever arm force (we call that a moment in eng speak) on the
shank head.

The top portion at the ball end is pushed towards the front of the TV

The bottom portion opposite of the ball end is pulled backwards.

This will have a twisting force (torque) on the TV's receiver cross tube because
the pin box transmits that WD force to the point where the Pin Box is attached
to the cross tube of a TRADITIONAL receiver cross tube

Where the difference in the GMT800 receiver is how they managed this force. It
also uses the cross tube as a torque tube, but they also use the bumper as a
transfer component.

That bumper transfer component consists of several pieces and is the food chain
to the TV frame. There is compliance (movement) through out that food chain

My assumption is that since they used the bumper, they then reduced the cross
tube wall thickness thinking it didn't need as much any more

Since the food chain to the TV frame via the bumper has so many components that
are BOLTED together, there is movement both bending the components and movement
in the bolted joints

The GMT800 receiver pin box moves much more than most traditional
designed receiver pin boxes. So much that some (many) bend beyond
their elastic point and into their plastic point and does not snap back. It stays bent.

Now switch to the WD spring systems and think this is where Andersen either
by design or luck that they chose a plastic spring.

All of the WD Hitch systems I've ever seen has a limited or small travel for
their springs. The Andersen system the smallest or shortest spring travel. It
would be interesting and germane if we could get hold of all of their spring
rate curves (lbs vs travel). Better yet if we could find their release speeds
and getting to porpoising that the Andersen does not, to date, have or is reported

The number of links on the traditional systems and the number of threads on the
Andersen system are indicators of how much tension is on the spring bars/trunnions
and plastic bushings.

That then transfer forces to the receiver pin box rotating it upwards, that then
creates torque on the cross tube

If that pin box is allowed to rotate too much, the travel of the spring system
of the WD Hitch runs out of gas, so to speak and is where I came up with 'consume'
during PM discussions with members here

True, not consumed, but runs out of distance or whatever you wish to call it

Don't believe that the GMT800 receiver pin box moves more than most other traditional
designed receivers...here are some links and pics

GM Hitch Deflection Measured - Comments Welcome
John's comment on his GMT800 receiver:

"The amount of deflection of the GM hitch was amazing"



One more thread on this: Receiver on GM seems to tilt up - best replacement?

Yes, just a few, but never the less, shows how 'some' of these GMT800 receiver
pin boxes do bend and this image shows how it 'tried' to transfer to the bumper
bottom, that then transfers to the inside bumper cross brace, that then transfers
to the bumper bracket to the TV frame rail.

Here is the diagram made up years ago during one of the discussions on the GMT800
receiver showing the force vectors (my opinion).


Here is another made up years ago with my opinion on quality of production of
the GMT800 receiver. Mainly my forensics on how that one broke off the pin box
from the cross tube. Actually had the guy send me that pin box and took hundreds
of pictures and made up this diagram during that dicussion


That is because of the amount of movement (flexing or porpoising) that the GMT800
has and mainly with those who tow heavy...the folks with lighter loads don't
report as many issues.

Here is the latest post on this exact issue, but GMT900. GMT900 pickups
continue to have this design, albeit bolstered by addition of gussets
inside the 'U' bracket. GMT900 SUV's have a more traditional receiver
but they continue to have it inside the bumper, which has crash crumple
duties and why it is limited to 1,000 lb tongue weight in WD mode
GMT-900 Hitches: How Many Have Replaced It? 2012May

To bring this back to the Andersen Hitch system...since the Andersen system
has a shorter spring travel, any receiver that has lots of travel will have
the Andersen system run out of gas (spring travel) so that it will no longer
be able to 'WD' the tongue weight

John's comment on his GMT800 receiver:

"The amount of deflection of the GM hitch was amazing"


and my coinage of 'consumed', which is a misnomer, but gets the idea
across to non-technical folks that I've been talking to...
-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?...

CHD_Dad
Explorer
Explorer
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!
2012 FR Surveyor Sport 295
2015 Nissan NVP 3500 SL 5.6L
Tekonsha P3 / "New" Blue Ox Sway Pro

JBarca
Nomad II
Nomad II
See comments in blue

Ron Gratz wrote:
John, I copied the following from the last post on Page 37.

I think it agrees with your statements above.

Ron Gratz wrote:
I think we're saying the same thing -- if the WD spring force is the same, the load transfer will be the same -- regardless of receiver torsional stiffness.

I think we also agree that, if receiver torsional stiffness is sufficiently low, physical restrictions on ball mount tilt and/or lift chain length might limit WD bar force.


Just one point of clarification --

JBarca wrote:

On a low stiffness system you may need to go 1.5 to 2 times the chain link less to get the same weight to move to the front axle. The hitch head may have rotated 3 to 4 degrees now for the same weight transfer.

If the receiver rotates 3.5 degrees, the excess rise at the end of a WD bar would be about 2.5". You would need to shorten the length of chain under tension by 2.5" to compensate for the receiver rotation. Is that essentially what you meant by "go 1.5 to 2 times the chain link less"? Yes this is correct. I did not do the exact math, I estimated from prior field observations.

Alternatively, you would need to increase the rearward tilt of the ball mount by 4-5 degrees. Or, you could use some combination of increased tilt and fewer links under tension.

Ron


Ron,

I do believe we have come to alignment! 🙂

Back to the Andersen hitch, there is no hitch head rotation due to the design concept which is one less adjustment availble. Only urathane spring compression. An RV'er following the directions may not be able to get the hitch to apply WD correctly if the reciever system has excess rotation and a low torsional stiffness. This is just a heads up to folks starting to use this hitch for something to look out for.

John
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

Ron_Gratz
Explorer
Explorer
John, I copied the following from the last post on Page 37.

I think it agrees with your statements above.

Ron Gratz wrote:
I think we're saying the same thing -- if the WD spring force is the same, the load transfer will be the same -- regardless of receiver torsional stiffness.

I think we also agree that, if receiver torsional stiffness is sufficiently low, physical restrictions on ball mount tilt and/or lift chain length might limit WD bar force.


Just one point of clarification --

JBarca wrote:

On a low stiffness system you may need to go 1.5 to 2 times the chain link less to get the same weight to move to the front axle. The hitch head may have rotated 3 to 4 degrees now for the same weight transfer.

If the receiver rotates 3.5 degrees, the excess rise at the end of a WD bar would be about 2.5". You would need to shorten the length of chain under tension by 2.5" to compensate for the receiver rotation. Is that essentially what you meant by "go 1.5 to 2 times the chain link less"?

Alternatively, you would need to increase the rearward tilt of the ball mount by 4-5 degrees. Or, you could use some combination of increased tilt and fewer links under tension.

Ron

JBarca
Nomad II
Nomad II
Ron,

H'mm there is one point that did not come across right as I can tell by your response. I'll insert in blue.

Ron Gratz wrote:
JBarca wrote:
Your statement about;
Ron Gratz wrote:
However, 100% of the torque which is generated by the WD bars will be transmitted to the tow vehicle via the receiver. It has nowhere else to go.
Yes it is true where 100% of the torque is going into the receiver, however it is not always being reflected at the front wheels of the TV. It is being lost in the process.---
Well, I thought we were in agreement. Now, I'm not sure. Perhaps it's just the words we're using to try to explain our thoughts.

First, I think we can agree the WD bars cannot generate torque as long as there is "slack" in the bar/hitch/drawbar/receiver/frame system.
As far as pure slack, (meaning excess clearance in the hitch shank to pin box for example) very little to almost no torque of significance is generated until the pure slack is taken out. Yes we agree on this.

There can also be deflection in the frame and in the mounting of the receiver. It is not slack as in clearance, it is a weaker member of the system. This is what I was referring to the lost part.


So, I suggest we focus on a system from which the "slack" has been eliminated.

IOW, if the bars are generating torque, there is no "slack" in the system.
This means 100% of the applied torque is transmitted to the TV and the loads on the front and rear axles will change in response to the applied torque.

Not trying to be nit picky but this is where the issues are coming. Not all TV receivers are created equal. Your statement about 100% of applied load being is transmitted to the front axles is a correct statement however the "amount" of load per WD adjustment can differ.

What has been seen in the field on some brand receivers is a low amount of torque transfer per amount of WD hitch adjustment. These are the problem receivers.

Not all TV receivers have the same level of torsional stiffness. WD bars can generate torque in a low torsional stiffness system however the amount of torque will be interactive with level of torsional stiffness for the amount of WD bar adjustment. And then there is the frame and joint deflection in some cases.

On a low torsional stiffness receiver the hitch head must rotate further to create the same WD bar load as opposed to a higher stiffness receiver.

On a high stiffness system when you decrease the chain links under tension (take up a link) you immediately get a large result of WD transfer to the front axle and you only rotated the head appox 2 degrees.

On a low stiffness system you may need to go 1.5 to 2 times the chain link less to get the same weight to move to the front axle. The hitch head may have rotated 3 to 4 degrees now for the same weight transfer.

Yes, granted 100% of the applied WD bar load is transferred to the front axle, however on a low torsional stiffness receiver the "amount" transfer is not much for a known hitch adjustment as compared to a higher torsional stiffness receiver.

If you run out of WD hitch adjustment trying to get the WD bar loaded enough to transfer the weight you want, the low efficiency of the receiver will not allow proper WD adjustment to occur. Again 100% of the what ever was generated went up front, it was just not enough.

This low efficiency receiver creates "an appearance" that the receiver is absorbing the WD adjustments you are making but not much is happening. Yes, in reality what little bit of torque you are creating is moving it is just not enough to do the work you want it too. Since you can only adjust the WD hitch so far, you cannot overcome the loss of inefficiency before running out of adjustment.



For example, if you apply a torque of 4000 lb-ft (CCW when viewed from driver's side) to a TV which has a 12.5' wheelbase, 320# will be added to the front axle and 320# will be removed from the rear.
I agree once you can create that torque

Laws of physics demand that the torque and force applied to the TV (in this simplified example, the applied force is zero) are exactly balanced by reactions at the axles.
IOW, 100% of the applied torque and force MUST be "reflected" in the axle reactions.
Neither torque nor force can be "lost in the process".

Again agree

When some folks talk about "consumed" or "eaten up" by the receiver, “I believe” they are referring to lost motion or excessive rotation in the receiver system.---
If that's the case, they also should refer to the differing amount of WD bar force resulting from excessive rotation rather than stating that the same amount of WD spring force does not transfer as much load. Again agree, once the WD bar load is created for the intended WD on the front of the truck, the rear axle weight will move. A low torsional stiffness and low efficient receiver requires excess rotation to create the same WD bar loads. The hope is you did not run out of WD hitch adjustment by this point.

I agree that some folks may think that when that take up 1 link of chain to create a lot of force that they actually did create a large force. You are suppose to get a visible reaction when the receiver is stiff. When you run into a low stiffness receiver the WD bar load increase per chain link is a lot lower to what they may be use to or that they can quickly see much load movement. It appears to be absorbed by the receiver when in pure reality it is not, it just did not move much weight and the WD bar force load is a lower as a result of it.


Ron


OK, did I pick better words to get the point across?
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

Ron_Gratz
Explorer
Explorer
BenK wrote:
Semantics, again, guys....I think violently agreeing in principle, but the verbiage is getting in the way...
Ben, if you believe semantics and verbiage is the problem -- can you rephrase the following to get your point across?

BenK wrote:
---So it DOES NOT transfer as much weight to the front axle as a traditional receiver would with the same WD spring forces
Or, could you please explain how having the same WD spring forces can result in different amounts of load transfer, if that really is the point you're making?

I feel this is quite important because we frequently are telling people that they need a certain amount of WD bar load to achieve a certain amount of load transfer.
It would be inconsistent to tell them they can get differing amounts of load transfer with the same bar load.

Please feel free to use 'engineer speak'. 🙂

Ron

BenK
Explorer
Explorer
Ron Gratz wrote:
JBarca wrote:
Your statement about;
Ron Gratz wrote:
However, 100% of the torque which is generated by the WD bars will be transmitted to the tow vehicle via the receiver. It has nowhere else to go.
Yes it is true where 100% of the torque is going into the receiver, however it is not always being reflected at the front wheels of the TV. It is being lost in the process.---
Well, I thought we were in agreement. Now, I'm not sure. Perhaps it's just the words we're using to try to explain our thoughts.

First, I think we can agree the WD bars cannot generate torque as long as there is "slack" in the bar/hitch/drawbar/receiver/frame system.
So, I suggest we focus on a system from which the "slack" has been eliminated.

IOW, if the bars are generating torque, there is no "slack" in the system.
This means 100% of the applied torque is transmitted to the TV and the loads on the front and rear axles will change in response to the applied torque.
For example, if you apply a torque of 4000 lb-ft (CCW when viewed from driver's side) to a TV which has a 12.5' wheelbase, 320# will be added to the front axle and 320# will be removed from the rear.

Laws of physics demand that the torque and force applied to the TV (in this simplified example, the applied force is zero) are exactly balanced by reactions at the axles.
IOW, 100% of the applied torque and force MUST be "reflected" in the axle reactions.
Neither torque nor force can be "lost in the process".

When some folks talk about "consumed" or "eaten up" by the receiver, “I believe” they are referring to lost motion or excessive rotation in the receiver system.---
If that's the case, they also should refer to the differing amount of WD bar force resulting from excessive rotation rather than stating that the same amount of WD spring force does not transfer as much load.

Ron



Semantics, again, guys....I think violently agreeing in principle, but the verbiage
is getting in the way...

My verbiage is from a few years ago and IIRC when John still had that Suburban
and was measuring the 'deflection' or whatever you guys wish to a call it, on his
receiver (GMT800)

Got tons of PMs asking for explanations. There were a few other threads smack on
that same topic...GMT800 receivers bending upwards (gone beyond their elastic
and into the plastic range of the material/design). There are pictures
of members GMT800 receiver pin box bent upwards, statically without WD
loading

I too can and do 'engineer speak', but not much here. Or try not to as the general
audience is NOT technical and ranges from a smidgin of techie speak
to PE's

I'll dig up some of those threads and link them on this thread, as it is time
and I think germane to this thread....Andersen WD Hitch System and how it works
on various OEM TV's receivers.

Via SmartPhone...excuse my fat finger typos
-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?...

Ron_Gratz
Explorer
Explorer
JBarca wrote:
Your statement about;
Ron Gratz wrote:
However, 100% of the torque which is generated by the WD bars will be transmitted to the tow vehicle via the receiver. It has nowhere else to go.
Yes it is true where 100% of the torque is going into the receiver, however it is not always being reflected at the front wheels of the TV. It is being lost in the process.---
Well, I thought we were in agreement. Now, I'm not sure. Perhaps it's just the words we're using to try to explain our thoughts.

First, I think we can agree the WD bars cannot generate torque as long as there is "slack" in the bar/hitch/drawbar/receiver/frame system.
So, I suggest we focus on a system from which the "slack" has been eliminated.

IOW, if the bars are generating torque, there is no "slack" in the system.
This means 100% of the applied torque is transmitted to the TV and the loads on the front and rear axles will change in response to the applied torque.
For example, if you apply a torque of 4000 lb-ft (CCW when viewed from driver's side) to a TV which has a 12.5' wheelbase, 320# will be added to the front axle and 320# will be removed from the rear.

Laws of physics demand that the torque and force applied to the TV (in this simplified example, the applied force is zero) are exactly balanced by reactions at the axles.
IOW, 100% of the applied torque and force MUST be "reflected" in the axle reactions.
Neither torque nor force can be "lost in the process".

When some folks talk about "consumed" or "eaten up" by the receiver, “I believe” they are referring to lost motion or excessive rotation in the receiver system.---
If that's the case, they also should refer to the differing amount of WD bar force resulting from excessive rotation rather than stating that the same amount of WD spring force does not transfer as much load.

Ron

rexlion
Explorer
Explorer
Instead of "consumed," I think I might suggest the word "absorbed."

Good to hear of the rains in Marinette, my sister's farm is just up the road (Stephenson) and the fields were way too dry there.
Mike G.
Liberty is meaningless where the right to utter one's thoughts and opinions has ceased to exist. That, of all rights, is the dread of tyrants. --Frederick Douglass
photo: Yosemite Valley view from Taft Point

JBarca
Nomad II
Nomad II
Ron Gratz wrote:
We had three days of rain here in the twin cities of Marinette, WI, and Menominee, MI.

Thanks Ron, We had a good Memorial day. Here in Central OH it was “full on” summer… 90 to 92 deg F all 3 days. Glad we had the AC in the camper to escape the heat and be able to sleep at least.

Ron Gratz wrote:
Receiver torsional stiffness does not enter into the relationship between WD spring force and load transfer.
JBarca wrote:
---When you do reach the WD spring force to be the same on a less efficient receiver after over adjusting the hitch, then yes the WD on the TV will be the same.---
Ron Gratz wrote:
I think we're saying the same thing -- if the WD spring force is the same, the load transfer will be the same -- regardless of receiver torsional stiffness.

I think we also agree that, if receiver torsional stiffness is sufficiently low, physical restrictions on ball mount tilt and/or lift chain length might limit WD bar force.

However, 100% of the torque which is generated by the WD bars will be transmitted to the tow vehicle via the receiver. It has nowhere else to go. Nothing is "consumed" or "eaten up" by the receiver.

Yes, we do agree. Once the WD bars gets loaded up enough, the weight will move. The words "consumed" or "eaten up" by the receiver I believe were used to describe what can and has occurred on some OEM receivers when excess flex is observed.

When I had my 2003 K2500 Suburban I had a level of what I would state is “receiver inefficiency” occurring. This may have been the beginning of realizing this vintage TV with the torsion bar front end suspension is not going to squat equal and GM did not want it too either. Just in 2003 they never put that in the owner’s manual and a 39 page post on RV.net was born…. By 2004 GM did list in the manual to not over compress the front end.

In my case I was up against a level of receiver to frame flex and possibly a level of excess receiver twist. I was losing the ability to transfer the hitch WD forces to the front of the truck. I did change the receiver to a Putnam XDR which had different adjusting attributes.

I did experience what I would describe is a large amount “receiver inefficiency” on my buddies 2002 Yukon (shorty WB Yukon). He had a Draw-tite hitch with the DC and he came to the house and we setup the hitch in my yard. He tried on his own to get this right but was having trouble as the WD settings where not responding like others have had.

He had a Travel-Star camper with an approx. 850# TW as measured by my Sherline tongue scale IRRC. This is now maybe 6 years ago, maybe more. He had 1,200# WD bars. We totally reset the hitch so the DC would not be in a binding condition in turns then started to adjust the head tilt to gain proper WD on the TV which in this case was to return the front axle to unhitched fender height.

His receiver was not responding like others I had adjusted. A washer of head tilt to the rear would result in not much to almost no movement on the front of the truck. It took almost 3 washers worth of tilt to get the front to change much. Granted in this case I did not have the dial indicator out measuring fender heights, we were using a tape measure. There was a zone of very high “receiver inefficiency” were hitch head tilt movements would not yield fender changes on the front of the TV to expected results. Once we started approaching 4 to 5 more washers we had an abrupt amount of movement.

On this setup once all washers that the head tilt pin could accept and an additional chain link we over drove the front end beyond unhitched and had to back off. This soft 1500 suspension you could overdrive the front end much quicker than the 2500.

When we were all done and the TT leveled out, the front was above 1/8 to 3/16” of unhitched height I stepped back and looked at the hitch head. WOW… to my surprise we had used up all of the head tilt and the hitch shank was very high up in the air. This Draw-tite head of that era had approx. 12 degrees of rear tilt with full washers. The head was tilted to the rear approx. 10 to 12 degrees with the shank close to that far above unhitched. That is a lot of rear head tilt and much more than normally needed to get a WD hitch to adjust properly with strong WD bars and a lighter TW.

In this case the receiver was rated at 1,500# in WD mode against an 850# loaded TW using 1,200# WD bars. That combo should not of given the end results it did. I told him this receiver is not responding correct, we have used almost all of the hitch settings and it still is not right. He took it home, ordered a Putnam Class 4 had his dealer installed it for him and even the dealer was shocked. The system adjusted out like it should with the receiver change.

I wish we had more time, I would of really liked to study that receiver to see where the loss of torsional twist was going. The end result was the pin box to the receiver tube and the receiver tube to the frame brackets rotated further then normally observed even on my K2500 original Burb receiver with a 1,200# TW which was the same series receiver.

Ron Gratz wrote:

As a side note -- the VESC V-5 Regulation and the corresponding SAE Standard indicate that a rotation of up to 5 degrees is acceptable.

Ron


Yes I know you found this spec a long time ago and was really good info. I would have to go back and find it to see if they state where the 5 degrees starts. I have found when a loaded TW is in the 900 to 1,200# range that the dead weight on the ball can rotate the pin box down approx. 5 degrees from unhitched position. Once WD is adjusted to return the TV front axle to unhitched height the pin box can be rotated up 2 to 3 degrees from the unhitched position. See here, NOTE, this is a 1,200# TW, using 1,200# WD bars, 2003 K2500 Burb, Putnam XDR receiver rated at 1,700# in WD mode.


Now see the same camper, same loaded 1,200# TW, same 1,200# WD bars, 2005 F350, Ford OEM receiver rated at 1,250# in WD mode.



The F350 OEM Super duty receiver has a tighter shank to pin box fit then the Putnam XDR did which made the XDR need more tilt.

I know that the suspensions are different between the K2500 Burb and the F350 as well as the TV WB. However the receiver ratings where a lot different too. I have not yet found a relationship between TW WD mode rating to when a receiver exhibits this high inefficiency problem. Some have lots of rating and the TW is low in comparison while some are at the high end of the ratings and work great.

Your statement about;
Ron Gratz wrote:
However, 100% of the torque which is generated by the WD bars will be transmitted to the tow vehicle via the receiver. It has nowhere else to go.


Yes it is true where 100% of the torque is going into the receiver, however it is not always being reflected at the front wheels of the TV. It is being lost in the process. The connection between the hitch shank and the front of the TV front end has more flex in some setups then others. Once the lost motion is accounted for the WD adjustments start showing up at the front axle, hopefully before you run out of hitch adjustment.

When some folks talk about "consumed" or "eaten up" by the receiver, “I believe” they are referring to lost motion or excessive rotation in the receiver system. Some GM’s from year 2000 to 2006, some Toyota 750# WD rated receivers on PU's and some F150's have experienced this effect to name a few I have run across. You can generally spot the issue by the hitch shank pointing up at a very high angle, 5 plus degrees from unhitched, trying to get the TV front end close to unhitched height.

This lost motion or excessive rotation in the receiver system may be in spec however you may also have a WD hitch that cannot tolerate it. I do not know if the TV OEM's and the WD hitch OEM's ever connected on what "normal" is suppose to be.

On the Andersen WD hitch I would suspect this high inefficiency of the receiver system would show up as seen by having a larger degree of thread exposed behind the urethane springs and by a large angle pointing up on the hitch shank.

John
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

Ron_Gratz
Explorer
Explorer
JBarca wrote:
Dog gone... Sorry I’m late to the party. Was out camping. 🙂
John, hope you had a good Memorial Day weekend. We had three days of rain here in the twin cities of Marinette, WI, and Menominee, MI. 😞

Ron Gratz wrote:
Receiver torsional stiffness does not enter into the relationship between WD spring force and load transfer.
JBarca wrote:
---When you do reach the WD spring force to be the same on a less efficient receiver after over adjusting the hitch, then yes the WD on the TV will be the same.---
I think we're saying the same thing -- if the WD spring force is the same, the load transfer will be the same -- regardless of receiver torsional stiffness.

I think we also agree that, if receiver torsional stiffness is sufficiently low, physical restrictions on ball mount tilt and/or lift chain length might limit WD bar force.
However, 100% of the torque which is generated by the WD bars will be transmitted to the tow vehicle via the receiver. It has nowhere else to go. Nothing is "consumed" or "eaten up" by the receiver.

I am not aware of any cases where receiver rotation was great enough to prevent sufficient load transfer from being obtained. Perhaps you do. I think there were some cases where people were unable to achieve equal front-end "squat" on their GMC vehicles and attributed the problem to a "weak" receiver, being unaware that the vehicles had suspension travel limiters (a.k.a. jounce bumpers) on the front.

As a side note -- the VESC V-5 Regulation and the corresponding SAE Standard indicate that a rotation of up to 5 degrees is acceptable.

Ron

JBarca
Nomad II
Nomad II
Dog gone... Sorry I’m late to the party. Was out camping. 🙂

Ron, you found that 5 year old post. :C LOL

Ron Gratz wrote:
BarneyS wrote:
Ron, I learned long ago not to try to argue a point with you (:W) BUT notice that Ben said "So it DOES NOT transfer as much weight to the front axle as a traditional receiver would with the same WD spring forces." (Bold added for emphasis) I still think his point was valid.:)


If the "WD spring forces" are the same, the load transfer to the front axle will be the same
-- unless you change WD bar length, TV wheelbase, ball overhang, ball to TT axles distance, or tongue weight.

Receiver torsional stiffness does not enter into the relationship between WD spring force and load transfer.


Ron, I agree with your statements as per the words on the screen. There is an element not being stated that does occur on certain receivers. Receiver efficiency to transfer an adjustment of a WD setting into the TV frame is a factor.

This leads to the receiver torsional stiffness discussion. The difference is the WD spring forces are not the same per what some may declare as a normal WD adjustment when a receiver has excess flex. When you do reach the WD spring force to be the same on a less efficient receiver after over adjusting the hitch, then yes the WD on the TV will be the same. If you happen to be an unlucky RV’er with a weaker receiver stiffness there are times you just run out of WD adjustment on the hitch before proper WD on the TV is ever obtained. The excess pin box to shank play (excess clearance) falls in here as well.

That being said, I totally agree Renojack is way off on his WD settings at this point. It may be he simply does not yet have the urethane springs tightened up enough. Or he has a combo problem. Since we have not seen a side view picture of his Anderson hitched to his Burb, we cannot tell if the pin box on the receiver has a large upward angle to it. Renojack, any chance of posting a side pic?

To all:

We have not yet run into a troubleshooting post on the Anderson hitch where the user has a low efficiency receiver where excess flex affects their ability to properly adjust the hitch. Sooner or later we will.

It will be really interesting to see this Anderson Urethane spring deflection chart. If someone obtains a copy, please post.
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

Ron_Gratz
Explorer
Explorer
Ya, I too am relieved we got that settled.

I was afraid I was going to have to dredge up this and subsequent posts :B

Ron

BarneyS
Explorer III
Explorer III
Whew! Glad to see that we agree, and that my long held thoughts were true. :B I was not reading into Bens comments the same thing you were and, of course, not reading with an engineers critical eye for detail. :W

Anyway, I thoroughly enjoyed our exchange and hope others got some meaningful information from it. That, in my mind, is the purpose of these forums.:) Thanks!
Barney
2004 Sunnybrook Titan 30FKS TT
Hensley "Arrow" 1400# hitch (Sold)
Not towing now.
Former tow vehicles were 2016 Ram 2500 CTD, 2002 Ford F250, 7.3 PSD, 1997 Ram 2500 5.9 gas engine