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]

BenK wrote:

renojack wrote:
snip...Where does the claim that the stock Chevy hitch absorbs weight distribution come from. I had the hitch checked an all is in order as far as loose or craced welds.

What happens is that the receiver pin box assembly bends on the round cross bar to 'consume' WD forces till it reaches its limits...then it will transfer (distribute) the WD forces.---

Every receiver will undergo some degree of pitch-axis rotation (twisting) when subjected to the pitch-axis torque generated by a WDH. The amount of rotation depends on the receiver's torsional stiffness and the magnitude of applied torque.

A receiver does not "'consume' WD forces until it reaches its limits". The torque which is applied to the hitch head by the WD bars is transmitted to the receiver via the drawbar and further is transmitted to the TV via the receiver.

If the torque is great enough to stress the receiver's steel to its yield point, the receiver will experience some degree of permanent rotation. This might or might not be great enough to detect visually.

Even if the receiver is stressed to its yield point (but not as far as its ultimate strength), it does not 'consume' WD torque. It still will transmit whatever torque is generated by the WD bars. However, if there is enough receiver rotation, you might find you need to increase the rearward tilt of the ball mount or decrease the number of links under tension -- but you will be able to load the bars and transfer load.

So, actually, the receiver will transfer all applied torque until it reaches its ultimate strength. Then it will undergo excessive rotation with decreasing transfer of torque, and eventually will fail if the rotation becomes great enough.

If cracks develop at critical locations, then the amount of torque required to produce yield stress or ultimate load will decrease.

Ron

[BenK]

renojack wrote:
snip...

Where does the claim that the stock Chevy hitch absorbs weight distribution come from. I had the hitch checked an all is in order as far as loose or craced welds.

Here are just 'some' of the threads on the GMT800 receivers

What happens is that the receiver pin box assembly bends on the
round cross bar to 'consume' WD forces till it reaches its limits...then
it will transfer (distribute) the WD forces. There are a multitude of
other issues with that design

First reported here below and is of a GMT800 8.1L Suburban just like the OPs:

Hitch Failure, the first report in 2003

This the first image on any forum that I know of and from the above
thread





A couple more:

Hitch Failure

One more Chevy hitch story




and some images of failed or compromised GMT800 receivers

[renojack]

I went back and weighed the 2005 Suburban and found 3660 on the front and 3280 on the rear. I contacted Andersen who is sending me a compression chart of in ches of compression to lbs of pull on the chains. I am hoping to gain the difference of what I see as 360-380 lbs or most of it by a couple more threads of compression on the urethane springs.

Where does the claim that the stock Chevy hitch absorbs weight distribution come from. I had the hitch checked an all is in order as far as loose or craced welds.

[Ron_Gratz]

renojack wrote:
The non WD weights were: Front 3200 Rear 4720 Trailer Axles 7000

The WD attached weights with 7 threads showing were: Front 3280 Rear 4680 Triler Axle 7000

The Suburban alone was 6980 and the trailer alone was 7980.

The wheel wells were just a little shorter in the rear than the front (less than an inch from unloaded.

Can I deduce that the tongue weght is 980 lbs and is the 80 extra lbs in front when hitched too much? Any adjustment needed? Any comments welcomed . I don't know where to attach the scale error of 40 lbs or is it significant?

Did you measure the front axle load separately for "Suburban alone"?. That's an important value. The main purpose of a WDH is to restore all or most of the load which was removed from the front axle.

The numbers provide two estimates of tongue weight -- (3200+4720)-6980 = 940# and 7980-7000 = 980#.

The numbers provide three estimates of GCW -- 3200+4720+7000 = 14920, 3280+4680+7000 = 14960, and 6980+7980 = 14960.

The difference of 40# in the first GCW easily could be resolved by changing the numbers to 3240+4740+6980 = 14960. That "adjustment" would give internally consistent values which would indicate that when WD was applied: 40# was added to the front axle, 60# was removed from the rear axle, and 20# was added to the trailer axles. This 2:3:1 relationship is consistent with how a WDH works.

However, as Bryan pointed out, the numbers indicate almost no load was being transferred. The indicated load transfer to the trailer axles was 20# versus approximately 200# transfer to the trailer which would result from proper WDH adjustment.

The indicated 40 or 80# added to the front axle is not nearly enough. With a tongue weight of nearly 1000#, when the WDH is properly adjusted, it will add back 400-500# to the front axle. And we need to know the unhitched front axle load in order to know how much load should be added back.

Ron

[carringb]

Those numbers look to me like you are barely transferring any weight at all with the hitch.

[BenK]

What year is your 8.1L Suburban?

If GMT800 (2000-2006), then the receiver should be replaced with a proper one. The
OEM receiver bends and consume WD forces. So it DOES NOT transfer as much weight
to the front axle as a traditional receiver would with the same WD spring forces

If GMT900 (2007 on), then note that the receiver is welded on and is part of
the bumper crumple zone. Why it is rated or limited to a max of 1,000 in WD mode
But you said 8.1L and IIRC, there is no big block offered on the GMT900 platform

[renojack]

I took the new Anderson installation on a Suburban 3/4 T 8.1 liter with 4WD to the CAT sacales today. Trailer is a 30 ft Pilgrim TT. The non WD weights were :

Front 3200 Rear 4720 Trailer Axles 7000

The WD attached weights with 7 threads showing were :

Front 3280 Rear 4680 Triler Axle 7000

The Suburban alone was 6980 and the trailer alone was 7980.

The wheel wells were just a little shorter in the rear than the front (less than an inch from unloaded.

Can I deduce that the tongue weght is 980 lbs and is the 80 extra lbs in front when hitched too much? Any adjustment needed? Any comments welcomed . I don't know where to attach the scale error of 40 lbs or is it significant?

P.S. 30-50 mph winds on the freeway were noticed but very manageable at 50-60 MPH speeds.

[renojack]

KKapa wrote:

Mike E. wrote:

renojack wrote:
Directions call for 100 lbs on the bracket bolts and 3 turns after contact on the setscrews. Just dropped it off at the shop for the weld option-2 inches on the trai;ing edge at the bottom of the outside bracket.

My instructions state 150 ft/lbs on the bracket bolts.

Ours say 100 too

My instructions are 100 on the frame bolts and "around" 150 on the receiver/ball bolts. I think we are all on the same set.

I had mine welded yestersday and the welder, who has also installed some others elected to weld 2" on the upper and lower outside trailing edge and the lower leading edge of the outside brackets. They are not going ANY place and I have more peace of mind. Operating as advertised. While only in town so far the biggest feature that I have taken advange of is the turning and backing radius compared to the friction slide bar sway control limitation.

[CHD_Dad]

Sounds like they are revising instructions on the fly as they work things out. I would have thought they did all that prior to selling these on the market, this hitch was supposed to have been in design for several years.

BTW - when I called Radauto to inquire about this hitch, the lady told me they drop ship all of Andersen hitches direct from Andersen. She told me that nobody online would actually stock these. If you look at the eBay sellers, they list the shipping point as Idaho which is where Andersen is located. Not exactly sure why they sell that way but it sure must be a profit maker for the sellers. No inventory or shipping costs to worry about!

[KKapa]

Mike E. wrote:

renojack wrote:
Directions call for 100 lbs on the bracket bolts and 3 turns after contact on the setscrews. Just dropped it off at the shop for the weld option-2 inches on the trai;ing edge at the bottom of the outside bracket.

My instructions state 150 ft/lbs on the bracket bolts.

Ours say 100 too

[Mike_E_]

renojack wrote:
Directions call for 100 lbs on the bracket bolts and 3 turns after contact on the setscrews. Just dropped it off at the shop for the weld option-2 inches on the trai;ing edge at the bottom of the outside bracket.

My instructions state 150 ft/lbs on the bracket bolts.

[renojack]

Directions call for 100 lbs on the bracket bolts and 3 turns after contact on the setscrews. Just dropped it off at the shop for the weld option-2 inches on the trai;ing edge at the bottom of the outside bracket.

[BenK]

renojack wrote:
The brackets appear to have rotated on the set screw. The bracket bolts were torqued to the recommended 100 ft lbs. Suprized me.

First mention of a torque value...previously posters have said the
instruction manual said to make 3 full turns, or something like that

Which is it?

Or am I mixing up the pointed set screw with the bolts holding the
brackets together?

[Gallifrey]

Yep, I think some bracket rotation is inevitable and ok, but they should stay put as far as moving along the beam.

[renojack]

I have an appointment this morning with a welder.