New Andersen WD hitch

[JBarca]

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

[Ron_Gratz]

There seems to be a wide range of experiences with the Andersen WDH.

Some not-so-good results are graphically depicted in this post on airforums.com.

Ron

[dennysemn]

mikedboyd wrote:
For 4 reasons, I traded in my Anderson on an Equalizer 1000# 4-point hitch today.

• DW could not turn the nut with my long-handle ratchet, and she has to be able to participate in the process

'Just wondering if I'm missing something here. Provided your hitch is already set up for your situation, and you know how many threads on the bolts should show, why not do this instead: After coupling, raise the tongue to allow easy and fast attachment of the WD chains. This method does not require the use of any long-handled ratchet, and the adjustments are already made.

I used to do the same with my old equalizer hitch on my older TT. Instead of using the snap tool to bring the torsion bars into the L brackets, I would raise the tongue a bit and just slide them in.

The Andersen Hitch has been on my trailer for about a year now and I love it.

[TomG2]

Sounds like you have a great dealer.

[mikedboyd]

For 4 reasons, I traded in my Anderson on an Equalizer 1000# 4-point hitch today.

• DW could not turn the nut with my long-handle ratchet, and she has to be able to participate in the process
• Could not lower tailgate with trailer attached
• All the talk about the couplers does have me concerned
• Dealer was willing to swap to the 4-Point for $100

[JBarca]

Ben, comments below

BenK wrote:


What isn't or hasn't been discussed is that the regular or traditional WD Hitch
systems 'do' beat up the coupler latch over time WITHOUT the constant contact
and force of the bushings.

The dynamic forces are NOT just from braking, or acceleration, but from all directions during a common road trip over the less than pristine roads, RR crossings,potholes, etc AT SPEED

What would you guys think or guess the forces on the latch is during a severe
whoop-do ?

Where the hitch is driven downwards to stretch the bottom plate to chain to rod to bushing?

There has been reports of the bushing shattering, or when the set screws employed
that they did not hold (allowed that bracket to move)

The back flex as nicknamed that occurs in a WD coming off a high up RR crossing, a big pot hole etc can be harmful to any WD hitch. If done quickly, the traditional WD hitch can crack a hitch head in extreme cases. I was told this by Reese tech service where this has had happen. In another thread about the Pull Rite a while (many few years now) we talked about back flex and when you go slow enough the truck will lift in the back to relief the very high spring force as it equalizes the loads. This helps relieve the pressure so go slow.

The Andersen or the traditional could have hard time in extreme fast back flex situations. While the traditional hitch may fair slightly better due to the operating principal, RV'ers towing heavy TW TT's should try not to bounce hard in those conditions. The dynamic jolt to the system is more than a handful... The Andersen may have a bent bottom chain plate and or urethane spring bracket issues.

BenK wrote:


John, you posted some pictures a while back of your trailer coupler
that had thousands of miles with a traditional WD Hitch system.

It looked very typical vs the miles on it and the latch pawl was
beat up. I've seen much worse and NOTE that is with a traditional WD Hitch system that does NOT have the constant contact that the Andersen architecture has.

Ben, don't know if you have me mixed up with another member. Yes I took pics of my ball coupler, however the latch shows very little to no wear. There is some light wear on the top formed dome of the coupler. I have a high TW, 1,400 to 1,600# pending loading and I have 1,700# WD bars. I do grease the ball and coupler.

Pic of my Shelby coupler here on page 7 of this thread

And this reply, shows pics of how that coupler works: Shelby coupler action

And more here with the grease wiped off and the latch action Shelby latch action

I have read recently that many have stated that the latch gets slammed when the truck stops with the traditional WD hitch. Well, after seeing mine and the way the dome of the main coupler is formed, I do not agree with this.

A traditional WD hitch exerts a very high downward force on the ball coupler pressing much more than the trailer TW. The only way the TT is going to slam the latch is if the forward force of the TT overcomes the added WD force pressing down on the ball and the TW to pop the tow ball out of that dome and then slide back in the free play to land on top of the latch.

Since my TT brakes are adjusted to stop with the truck, I do not get the trailer pushing the truck 99% of the time. The 1% is when my 7 wire cable fell out and the truck had to do all the work. Even then I caught it early, eased the truck to a stop and there was no slam. (and since then I now always tie the 7 wire cord plug cover over the plug to not hop out, live and learn)

I'm not stating the latch never gets touched, but it is far and in-between on my trailer. There are no shinny or even dull burnish marks on my coupler latch. There are wear marks on the front of the coupler and the top dome.

John

[JBarca]

Ron Gratz wrote:

JBarca wrote:
Hi Ed, Welcome to the discussion! When you came up with 1,000# per chain load, what are the assumptions surrounding this?

John, I don't know how Ed did it, but here is my approach to defining the relationship between tension and load transfer.

First we need to define some dimensions and variables. Let:
a = tow vehicle wheelbase
b = ball overhang (longitudinal distance from TV rear axle to ball)
c = distance from ball to mid-point between the TT's axles
d = perpendicular distance from Andersen chain to center of ball (reported by Andersen owner to be 6.5")
TW = tongue weight
LTT = load transferred to TT's axles
LF1 = load removed from TV's front axle due to TW without WD applied
LF2 = load transferred to TV's front axle when WD is activated
T = Andersen chain tension per chain
M = moment (torque) generated by Andersen chain tension (total for 2 chains)

then (assuming zero pitch-axis rotational friction between ball and coupler)

M = 2*d*T
LTT = M/c = 2*d*T/c
LF2 = LTT*(b+c)/a = 2*d*T*(b+c)/(a*c)
also
LF1 = TW*b/a

If we want to restore a load equal to some percentage (call it FALR) of that which was removed from the front axle, we have:

LF2 = LF1*FALR/100, or 2*d*T*(b+c)/(a*c) = FALR*TW*b/(a*100)

solving for chain tension (per chain) gives

T = FALR*TW*b*c/{2*d*(b+c)*100}

for example, if: b=60", c=200", d=6.5", TW=600#, and you want to restore 50% of the load removed (FALR=50)

T = 50*600*60*200/(2*6.5*260*100) = 1065# per chain

Ron

Hi Ron,

Catching back up on this.

I used your formula,

Ron G wrote:
solving for chain tension (per chain) gives

T = FALR*TW*b*c/{2*d*(b+c)*100}

And check it against my assumptions with my TT & TT.

I my case I used a 1,400# TW, 90% FALR and at the time I estimated "d" to be 8" where you used 6.5" So I tweaked the formula to use 8 to see if it came close to how I backed into it.

Both methods came in close to similar areas.

Using your formula gave 4,050# per chain.

Using my method 3,919# per chain or 131# less than you did.

From here:

JBarca wrote:
In my case I have an actual 1,400# TW and this hitch is rated that high. That is approx. 1,100# at each snap up chain using 28.5” long WD bar or 5,225 ft. lb of torque into the receiver. The Anderson using it’s 8” tow ball would need 7,838# total chain force to create this.

There is some error in this as my Reese Tow beast shank is longer then the Anderson shank but it get’s me in the league of feeling what chain forces are going on with the Anderson.

The 28.5” WD bar compared to the 8” long tow ball is the difference in the mechanical advantage of the 2 hitches for WD. The Anderson will always have to use higher chain force to get the same WD.

I used the spread sheet you sent me many years ago on backing into the chain force of a traditional WD hitch for a given TV and TT. Once you have the chain force you can create the torque in the receiver to the amount of weight returned to the front of the TV. Since I had scale weights and know how my hitch was adjusted, I figured out the torque in the receiver with the Reese then put the Andersen in the same setup to reproduce the same torque, thus creating a chain tension in the Andersen.

Point: 2 approaches that come very close to the same answer.

Also , thanks for the link to the AS site. I read that a while ago but did not follow the latest info.

[CHD_Dad]

Just wanted to chime in. I have had the Andersen for about a year now and taken a handful of trips. I find many pros with the design and execution. The towing experience was 95% of the way there for me. Unfortunately I cant get the Andersen to put enough weight back up front on my setup. My truck does not like being light up front and that was a deal breaker.

I can also say this - the people at Andersen have been very good with talking with me. It took a while to get things going back and forth but I ended up speaking with their VP for quite a while. He is a really nice guy and was very helpful and open to talking with me. He admitted to the hitches shortcoming with weight distribution. They knew they would hit a limit but said that after speaking with many hitch owners and lots of testing they decided that they were happy with the setup. When they designed it they knew they would need to compromise somewhere, almost all designs have a compromise. They were aiming for simple, lighweight, better ride with reduced bounce and keeping it clean (grease free). On all of those points they nailed it.

As for the coupler, I honestly dont know what model coupler I have on my FR. It doesnt show any abnormal wear that I can tell but it is also a brand new TT with only a handful of trips. It was a concern of mine after being brought up for long term use.

For me the Andersen will not work and I am in the process of shopping for a new WD system. For people who dont need a lot of weight moved forward or are not concerned with that I think its a very viable option to look into. I truly do wish they could have made it work on my setup, the ride when towing was near perfect.

[mikedboyd]

Seems to me that most agree it doesn't make sense from a good engineering perspective, too much stress in all the wrong directions, etc. On the other hand, those that have them mostly seem to like them, like me (so far). Interesting conversation.

[BenK]

Just a note that to 'watch' or 'keep an eye' on it is only going to catch
(if you see it) the obvious issue (crack, looseness, etc), but what about while
towing out 'there' ?

It does not surprise me that the set screw holes (or gouged indentation) has
elongated. That is how the Andersen works

Wonder about those who welded their bushing brackets onto the tongue

Since no compliance, the bushings take it all

Depends on the amount of compression and how much stroke is left before those
bushings fatigue to crack/break apart/etc

If me, I'd have many, many more bushings in series to increase the potential
stroke of the spring stack. Design the recommended compression to somewhere in
the middle of that stroke (based on expected or desired WD force vs the tongue)

Ditto that force dynamics exercise...that is what I saw and noodled when John first
posted this new to me hitch system

Still think an elegant design, but as usual...the devil is in the details and
the 'testing', which in today's product world...those test mules are us...

THANK YOU to Ron for posting that link and never saw a coupler latch like that.
Interesting and initially would seem better for the way Andersen loads coupler
latches...weird and needing more noodling. First blush says not in the bottom
area of that latch design, but upwards in how those two 'MOVING' components
interplay. Since both moves, wonder if over time, that very movement becomes the
issue?

Again for those who don't know what the or how the latch does it'w work...

The ball snugs into the front (towards the TV) of the formed coupler dome, which
has a lower hemisphere that goes below the equator

The latch then moves a pawl or some such into the back of the ball and creates
a lower hemisphere.

Now the balls equator is larger in dia than the subsequent dia of the lower
hemisphere created by that latch

Why when the ball is 'stuck', most will back up the TV into the coupler while
the latch is opened.

This moves the ball away from the front dome area and into an area that has an
opening larger than the ball's equator (circumference or dia)

Since this discussion on forces on the latch...ask you guys to noodle what might
be the forces on the latch during a whop-d-do

Assume the bushings have a very slow rate of change (why it works so well to snub
porpoising) will it compress more during that XXX milliseconds during the bottoming
of that whop-d-do?

I say or initially think, it will NOT compress very fast or fast enough to
absorb those forces and why the reported bushing bracket set screw indentation
elongation or movement

What is the force over and above the preset via torque on the bushing nut on
the bushing?

How many cycles is that bushing(s) good for at those forces?

Now that then brings into question the chain clevis that is ground down, polished
to reduce the cross section of it...how close to the plastic point of the
metal? How many cycles will it endure at those forces?

Since the chain is welded to the bushing rod, what is the condition of the
subsequent weld(s)? Did the chain lose it's temper, or was it dead soft metal
chain to begin with?

Hope there isn't any angular movement between the rod/chain and the bushing
bracket...tin canning is a potential on that now questionable weld (to me)


Note to those who are not in design, nor in CDR cycles of any design...my questions
are NOT pessimistic, but part of the design review cycle.

[Slowmover]

eb145 wrote:
I am thinking about getting an Andersen WDH.

And I had no idea of what kind of coupler I have on my trailer.

I now know it is a Redline CA5400 coupler. And NOT the Atwood 88xxx series coupler.



I even found a little video for it:
Redline CA5400 trailer coupler at ETrailer.com

Ed

I believe you'll want to examine some of the AIR posts to see the differences between the two ATWOOD coupler types. Just a different brand may not be enough, it would be the design of things.


Another recent post over there by a contributor who got fed up with lack of FALR and replaced the ANDERSON with a PRO PRIDE found that the ANDERSON bracket mount fastener holes to the TT frame had elongated in the approximately 4k miles (IIRC) of towing his mid-sized AIRSTREAM.

.

[eb145]

I am thinking about getting an Andersen WDH.

And I had no idea of what kind of coupler I have on my trailer.

I now know it is a Redline CA5400 coupler. And NOT the Atwood 88xxx series coupler.



I even found a little video for it:
Redline CA5400 trailer coupler at ETrailer.com

Ed

[TomG2]

eb145 wrote:

Ron Gratz wrote:

JBarca wrote:
Hi Ed, Welcome to the discussion! When you came up with 1,000# per chain load, what are the assumptions surrounding this?

John, I don't know how Ed did it, but here is my approach to defining the relationship between tension and load transfer.

First we need to define some dimensions and variables. Let:
a = tow vehicle wheelbase
b = ball overhang (longitudinal distance from TV rear axle to ball)
c = distance from ball to mid-point between the TT's axles
d = perpendicular distance from Andersen chain to center of ball (reported by Andersen owner to be 6.5")
TW = tongue weight
LTT = load transferred to TT's axles
LF1 = load removed from TV's front axle due to TW without WD applied
LF2 = load transferred to TV's front axle when WD is activated
T = Andersen chain tension per chain
M = moment (torque) generated by Andersen chain tension (total for 2 chains)

then (assuming zero pitch-axis rotational friction between ball and coupler)

M = 2*d*T
LTT = M/c = 2*d*T/c
LF2 = LTT*(b+c)/a = 2*d*T*(b+c)/(a*c)
also
LF1 = TW*b/a

If we want to restore a load equal to some percentage (call it FALR) of that which was removed from the front axle, we have:

LF2 = LF1*FALR/100, or 2*d*T*(b+c)/(a*c) = FALR*TW*b/(a*100)

solving for chain tension (per chain) gives

T = FALR*TW*b*c/{2*d*(b+c)*100}

for example, if: b=60", c=200", d=6.5", TW=600#, and you want to restore 50% of the load removed (FALR=50)

T = 50*600*60*200/(2*6.5*260*100) = 1065# per chain

Ron

Now this calculation makes me smile - it has been many years since my Statics and Dynamics classes! I especially like it because it shows my main assumption might actually be correct. But I will disclose how I came up with the 1,000# per chain estimate: several posts discussed a similar setup as mine that had various real measurements that showed about 1,000# per chain transferring the correct amount of weight to the front axle.

Ron's comment about the safety spec requiring that force for only 5 seconds is very relevant new information for me.

So a simple comparison (using rough estimate numbers - not exact) might be like this:

8 hours = 28,800 seconds. Let's round up to 30,000 seconds for a long day of driving.

And I have a 14,000# rated coupler.

Safety spec requires 3X the coupler rating for 5 seconds:
42,000# force for 5 seconds required by safety spec.

Andersen WDH exerts a constant baseline force:
2,000# force for 30,000 seconds
(Caution: THIS 2,000# force number will vary significantly for each rig)

Traditional WDH exerts a constant baseline force closer to zero.

Both couplers experience lots of dynamic forces from road use in all directions on top of the baseline (static) force.

So the obvious difference (as everyone following this thread knows and I am catching up on) is the Andersen WDH has a constant baseline force applied to the coupler in a rear direction.

And the baseline force on the coupler will vary significantly per rig depending on how much force is needed to get proper weight distribution.

And one coupler type (Atwood 88xxx series) so far has been shown to not like that constant baseline force.

Very enlightening.

And my 1,000 lbs per chain assumption is quite different from John's calculations that show almost 3,000 lbs. per chain for his 1,400# tongue weight setup. John's calculations.

I guess for now the bottom line for me is the more you have to compress the urethane bushing for proper weight distribution the more baseline force you are putting on the coupler. Know your coupler and keep an eye on it.


I just went outside, laid down on the gravel and looked "up" at the inside of my coupler for the first time. (Sunday morning in my pajamas:) )

What a great forum.

Ed

What did you see? Are you using an Andersen hitch and looking for damage? Pictures would be great if you are.

[BarneyS]

eb145 wrote:
Snip...
I just went outside, laid down on the gravel and looked "up" at the inside of my coupler for the first time. (Sunday morning in my pajamas:) )

What a great forum.

Ed

Pictures!!!! We need pictures! :B
Barney

[eb145]

Ron Gratz wrote:

JBarca wrote:
Hi Ed, Welcome to the discussion! When you came up with 1,000# per chain load, what are the assumptions surrounding this?

John, I don't know how Ed did it, but here is my approach to defining the relationship between tension and load transfer.

First we need to define some dimensions and variables. Let:
a = tow vehicle wheelbase
b = ball overhang (longitudinal distance from TV rear axle to ball)
c = distance from ball to mid-point between the TT's axles
d = perpendicular distance from Andersen chain to center of ball (reported by Andersen owner to be 6.5")
TW = tongue weight
LTT = load transferred to TT's axles
LF1 = load removed from TV's front axle due to TW without WD applied
LF2 = load transferred to TV's front axle when WD is activated
T = Andersen chain tension per chain
M = moment (torque) generated by Andersen chain tension (total for 2 chains)

then (assuming zero pitch-axis rotational friction between ball and coupler)

M = 2*d*T
LTT = M/c = 2*d*T/c
LF2 = LTT*(b+c)/a = 2*d*T*(b+c)/(a*c)
also
LF1 = TW*b/a

If we want to restore a load equal to some percentage (call it FALR) of that which was removed from the front axle, we have:

LF2 = LF1*FALR/100, or 2*d*T*(b+c)/(a*c) = FALR*TW*b/(a*100)

solving for chain tension (per chain) gives

T = FALR*TW*b*c/{2*d*(b+c)*100}

for example, if: b=60", c=200", d=6.5", TW=600#, and you want to restore 50% of the load removed (FALR=50)

T = 50*600*60*200/(2*6.5*260*100) = 1065# per chain

Ron

Now this calculation makes me smile - it has been many years since my Statics and Dynamics classes! I especially like it because it shows my main assumption might actually be correct. But I will disclose how I came up with the 1,000# per chain estimate: several posts discussed a similar setup as mine that had various real measurements that showed about 1,000# per chain transferring the correct amount of weight to the front axle.

Ron's comment about the safety spec requiring that force for only 5 seconds is very relevant new information for me.

So a simple comparison (using rough estimate numbers - not exact) might be like this:

8 hours = 28,800 seconds. Let's round up to 30,000 seconds for a long day of driving.

And I have a 14,000# rated coupler.

Safety spec requires 3X the coupler rating for 5 seconds:
42,000# force for 5 seconds required by safety spec.

Andersen WDH exerts a constant baseline force:
2,000# force for 30,000 seconds
(Caution: THIS 2,000# force number will vary significantly for each rig)

Traditional WDH exerts a constant baseline force closer to zero.

Both couplers experience lots of dynamic forces from road use in all directions on top of the baseline (static) force.

So the obvious difference (as everyone following this thread knows and I am catching up on) is the Andersen WDH has a constant baseline force applied to the coupler in a rear direction.

And the baseline force on the coupler will vary significantly per rig depending on how much force is needed to get proper weight distribution.

And one coupler type (Atwood 88xxx series) so far has been shown to not like that constant baseline force.

Very enlightening.

And my 1,000 lbs per chain assumption is quite different from John's calculations that show almost 3,000 lbs. per chain for his 1,400# tongue weight setup. John's calculations.

I guess for now the bottom line for me is the more you have to compress the urethane bushing for proper weight distribution the more baseline force you are putting on the coupler. Know your coupler and keep an eye on it.


I just went outside, laid down on the gravel and looked "up" at the inside of my coupler for the first time. (Sunday morning in my pajamas:) )

What a great forum.

Ed

[TomG2]

PHS79 wrote:
Our TT has the 81911 and we have the Andersen hitch last year we put on only about 2000 miles. If we still have the TT and the couple would have to be replaced at some point down the road, I would install a Bulldog hitch. We have Bulldog couplers on numerous trailers, one of which has more than 100,000 miles on it and still has the original coupler.

I do a "pre trip inspection" everytime that we are packing for a weekend. Because of the issues that some have had with the Andersen hitch and different couplers, I make sure to check the coupler just to look for anything out of the ordinary.

Checking over the coupler is a good practice no matter the brand of hitch used. I do. Been doing it long before I got an Andersen. Some couplers are pretty flimsy.