Dual Cam Setup

TUCQUALA wrote:
Notice the differences: higher chain hook on old, and closer in to the frame. Hinge point is higher and further out than the "HD" style.

Tough one for me to try to figure out. If we can assume that the chain hangs straight down in both cases then it seems like the old one would be better. If the hook is closer to the frame then I would assume there's less force generated trying to rotate the bracket. I can't really tell from the photo what the difference is - I'm not sure if it's enough to matter. The hinge point being further out seems like a good thing too. The snap-up needs to bend/move more before all the load is on the little keeper pin. I also like the fact that the old one does not have those two "points" trying to dig into the face of the frame.

Now if something goes bad, and the old bracket does manage to rotate, it could be worse. It's longer so would be like turning a bolt with a longer wrench.


Based on what we now know, we should be preventing rotation (bolt the snapup in) and protecting the frame (backer plates - I would do both sides of the frame).

If we assume the snap-ups are secure and have the frame protected then it may not matter which one you use. I would go for the new one, just because it's been beefed up in a number of places.

Not trying to hijack this commentary, but I felt this is particular to both your problem, and mine.

JBarca pics of his earlier HD snap up made me go look at a few differences with my much older ones. Mine are '03 vintage, and my son's are '05 vintage and are exactly the same. His setup was 1000# which are the bars I was using when my hitch cracked. Notice the differences: higher chain hook on old, and closer in to the frame. Hinge point is higher and further out than the "HD" style. The metal bar clamped is positioned where the frame would meet the snap ups.






So my thoughts are: How much more or less twisting force is applied to the trailer frame under normal towing events, which would include turns, driveways, twists and turns, by each of these snap ups??? Which would be better for these new, weaker trailer frames???

I think the older style would be less prone to have a failure. I know I have had one fail with the new hitch, but I still believe there was something abnormal happening during the first setup. The snaps and bangs were way out of line.

Appreciate all your thoughts on this, esp from you and JBarca!!


Gerry

JBarca wrote:

And even more so, is there are standard for side loads of a snap up bracket? I myself do not yet know of one.

I've asked Reese for an engineering document outlining the loads they expect to see on the bottom of the A-Frame bracket under load with heavy tongue weights. I think I also asked for the load a 6" tube frame should handle at the center of the face. I haven't gotten any response. I have responses to subsequent emails, so I have to assume it's been ignored. I specifically asked for this as an aid for building a warranty claim with Coachmen.

JBarca wrote:

The Hitch manufactures and the TT manufactures may need to talk more.

Yes, that's what should happen. But what appears to be happening is the the end user is stuck in the middle, re-engineering these products in order to prevent recurring damage or as a safeguard to avoid it.

JBarca wrote:

Who is the one to take the lead? Build a hitch that works on every TT or build a TT that works with the WD hitches now avaible on the market? The conventional WD hitch has not changed much in the last 50 years... TT A frames have.

There must be some parameters these systems were designed around. That info should be readily available. It's not.


I've also asked Reese if they have a statement for Coachmen saying that a properly installed Dual Cam System does not void any warranty. They didn't answer that question either.

So, in my opinion, the solution should be that the trailer manufacturer and the hitch manufacturer jointly declare that a properly installed system will be supported under warranty. If there are problems the hitch manufacturer and the trailer manufacturer can work out who remedies it, but at least the end user isn't left out in the cold. Since the hitch manufacturer and trailer manufacturer are jointly warranting the end to end system, there's incentive for both the cooperate to get it right.

JBarca wrote:


I have not yet figured out if the DC addition to the WD hitch created all this frame issue. Not that anyone is yet pointing to the DC to aggravate this frame bend at the snap up issue, just I myself have not connected those dots yet.

I believe the DC contributes to the forces attempting bend in the face of the frame.

We agree there's considerable force at the bottom of the snap up. And I think we agree that it gets worse if anything goes south (snap up bends, frame bends, etc.)

In addition, I think there's a rotational force on the dual cam mount where it wants to rotate into the face of the frame. Those self tapping screws in thin sheet metal aren't much of a deterrent.


This photo from the pinch bolt shows some evidence of that rotation:



I'm pretty sure the dual cam frame bracket rotates a little as soon as a load it applied, so some rotational force is always there, it's just a matter of how much.

If my analysis is correct, then the dual cam design is "doubling down" on trying to bend the frame vs just using weight distribution with snap up bars.

Hi mrekim,

I feel your pain and frustration. And I can tell you are open minded about this trying to learn as much as you can along the way.

This issue goes beyond the Reese snap up. Being open minded lets look at some other hitch manufactures and see if the same thing would of occurred with the frame and snap up. I picked these brands specifically as the snap up concept is the same as the Reese.

http://eaz-lift.com/eazlift/ EAZ lift. They have been around a long time even if recently acquired by Camco.

http://www.huskytow.com/product/trunnion-bar-weight-distribution-hitch/ Husky Towing Products. These folks have been around a long time using the same concept snap up.

http://www.curtmfg.com/Category/80/Weight%20Distribution Curt Mfg. A reputable name in the industry selling the conventionla WD hitch.

http://www.vtowing.com/About.aspx Valley Towing Products, Their web site I cannot seem to navigate right or something is not working. Here is a pic of the hitch from Cabelas Valley hitch

There are others on the market that make the same style snap up, Robin Industries etc. All those style hitches have the same underlying snap up principal of forces. Granted some may be bent to be better on the 90 degree top bend, however the side load on the frame is not that much different. They are all no drill snap ups as listed. Have to dig into if they recommend bolting on higher TW's

I have not yet figured out if the DC addition to the WD hitch created all this frame issue. Not that anyone is yet pointing to the DC to aggravate this frame bend at the snap up issue, just I myself have not connected those dots yet. So this leaves us with your exact A frame setup, your TW, your very capable tow vehicle, 1,200# WD bars and a WD hitch hanging on a snap up bracket of the Reese “style”.

It is a fact that making a turn with a conventional WD hitch where the truck and trailer wheels are on different surface angles changes the hitch head tilt in relation to the trailer A frame. If the trailer wheels are on level ground and the truck on a surface that on angle (say 5 or 10 degrees for example) in relation to the TT, the hitch shank in the back of the truck is going to follow the truck and the hitch head with the tow ball in the coupler will pivot the WD bars. The hitch head movement will change the loading on the inside and outside turn WD bar. How much it will change will depend on the angle and the head tilt of the hitch.

On the DC, since the chain does not swing like a non DC WD hitch it is easier to spot that the inside turn WD bar can totally unload in spring force. And it does not take very much angle between the truck and trailer. I have seen it and measured it in my own driveway.

On the non DC hitch the chain attached to the WD bar will swing towards the TT. Since it is attached to the WD bar, it is harder to see that inside WD bar unloading. And it may take more angle difference between TV and TT to go to zero load, however the load is still significantly reduced because the hitch head is titled in a force unloading direction.

Once the inside turn WD bar unloads in force or a majority of the force, the chain force pulling on the snap up of the outside turn WD goes very high. This is where the heavy force comes from that did the damage to your A frame.

The A frame has to take this side pulling chain force directed into the frame rail by the snap up and not deform under load. Reese may be getting the black eye on this one as it was the brand in use at the time. The question is what industry standard exists for A frames on trailers that are known to have to use a WD hitch? And even more so, is there are standard for side loads of a snap up bracket? I myself do not yet know of one. I will start looking though. The Hitch manufactures and the TT manufactures may need to talk more. Who is the one to take the lead? Build a hitch that works on every TT or build a TT that works with the WD hitches now avaible on the market? The conventional WD hitch has not changed much in the last 50 years... TT A frames have.

I have a flat deck equipment trailer at home, rated for 9,900#, The A frame is made from 6” channel and there is a 6” wide C channel welded in left to right between the frame rails near the sanp ups as part of a hydraulic tilt lift. I can post a pic later tonight. This thing is even beefier then my 6” channel , 10,000# camper. Many enclosed cargo trailers use tube A frames. I have towed them often just do not own one right now to go out and measure the tube thickness. Many in the 10,000# class may be 6 to 8" structrual tubing.

Point in this is the A Frame is in the middle of the mix. Would any one of those other brands that have been around a long time be any different than what the Reese did? They are all no drill snap ups and the length of the snap up it not that much different. The pressure points acting on the A frame side wall are similar. If Coachman comes back and declares the Reese DC is not compatible with their trailer frame, did they also wipe out all the other brands that use the same style snap up?

More to think on.

JBarca wrote:
took the preemptive strike before issues showed up.

Yes, it seems with the Reese stuff, that's required. Basically you need to re-engineer the system. The thing that wasn't obvious to me is that adding through bolts and backer plates, etc. is not "insurance" against some event like a sharp turn or backing and a tight angle into a camp site. You need it just to get out of the driveway.....

JBarca wrote:
At that time this did not show up in the instructions as it does now, only knew by phone call.

Mine said to use a self tapping bolt only for Jayco trailers with coupler at the bottom.

JBarca wrote:

Mine only have 2 holes in the bracket to allow it to be bolted. The set screw pinch bolt must be in place or the entire bracket will bend off the frame at the top pivoting on the 2 lower snap up bolts.

This implies another pretty large point stress on that thin steel frame. Can Reese really claim they have a soundly engineered system for current frame designs?

Based on my conversations with tech support, I think Reese believes that all failures related to their system are simply unexplained outlier events or installer error. I'm not sure they are even considering the possibility that their design may not be compatible with currently shipping trailers.

JBarca wrote:

Seeing your tube frame crush like it did really starts to question this setup.

I don't understand Reese's lack of concern for the frame issues.


I'm trying to stay optimistic until I get the dealer to determine if the frame will be covered under warranty. Waiting weeks for an appointment to determine coverage is frustrating.

I'm hoping that at the very least I'll have a formal statement from Coachmen as to whether the Dual Cam system is compatible with the frames on their heavier trailers.

JBarca wrote:

I have a camping buddy with a Jayco and a 1,200# Reese DC and they are tube frames. I'll have to check he may have increased now to 1,500# bars. He did through bolt the snap ups and put a full backer plate on the inside. He has had the rig now many years and it not come up as an issue for him, again he bolted it to prevent the start of the problem. Which seems to point to being key. Once the bracket starts to bend or the frame deflect, all bets are off.

Yes, so more re-engineering to get it to work. Also, it seems that the margin of safety with respect to protecting the frame is pretty small.

JBarca wrote:

The rigidity of the tube frame for sure is in question. Is his older camper thicker?

Yes, good question. Why use 1/8" tube vs 1/4" C. The 1/4" C should only be a little heavier. It would stand up to these systems better. And it would be easier to maintain with respect to rust prevention.

JBarca wrote:

the Reese SC hitch

I looked at that. Some (most?) Reese competitors have a no drill solution as well.

I can't imagine what caused Reese to go from a no-drill to self tapping screw solution.

JBarca wrote:

As TT manufactures continue to push towards lighter frames to save weight, they should address this area. It is not that hard to add frame plates on day 1 as they know people have to use a WD hitch on these heavy TW campers. They are letting the WD hitch mfr deal with it.

I think it's getting put on the customer to some degree as well. For example, I installed this according to the instructions and have had no "abnormal" towing events. Reese has already stated that they're not interested in dealing with the frame.

Now Coachmen may step up, or even better, they may work with Reese to remedy things for everyone who may be impacted. I'm doing my best to keep an open mind. Waiting many weeks to even get it looked at for warranty consideration is frustrating...



What would be really interesting is if a Reese competitor stepped in and said "we have a better system - we'll fix you up"...

Here are some more pics. I have the older lighter brackets but bolted on from day 1, 1,600# TW and 1,700# bars and 6" C Channel frame and using the 2 lower bolts. I had the good fortune of being on the forum long ago when snap up failures where talked about and I took the preemptive strike before issues showed up. The heavy snap up's where not even out then on the 1,700# hitch. Where I came up with the 1,200# number was a call to Reese tech support. They stated "in some cases" customers have reported snap up failures in turns on these heavier TW's. They had no problem at all bolting on the snap up's. At that time this did not show up in the instructions as it does now, only knew by phone call. It however never says anything about what loaded TW's need these. http://www.reeseprod.com/content/downloads/installation/N66006.pdf

Mine only have 2 holes in the bracket to allow it to be bolted. The set screw pinch bolt must be in place or the entire bracket will bend off the frame at the top pivoting on the 2 lower snap up bolts.

My older brackets where never 90 degree square even in the free state. I never liked that fact however the edge that rests agasint the frame corner is taking all the load and since I'm bolted flat on a rigid surface, the setup can deal with the bend.

Here are some pics to help show setup














Seeing your tube frame crush like it did really starts to question this setup. I have a camping buddy with a Jayco and a 1,200# Reese DC and they are tube frames. I'll have to check he may have increased now to 1,500# bars. He did through bolt the snap ups and put a full backer plate on the inside. He has had the rig now many years and it not come up as an issue for him, again he bolted it to prevent the start of the problem. Which seems to point to being key. Once the bracket starts to bend or the frame deflect, all bets are off.

The rigidity of the tube frame for sure is in question. Is his older camper thicker?

In this case, any brand snapup that is simialr with a top clamp like the Reese could yield the same effect left unbolted.

This type of mounting on a thinner tube frame may be a better option where the snap up has a heavy plate on both inside and out and uses full length straps on front and rear of the bracket along the frame. 4 bolts then hold the load clamped over the frame. This hanger is only one strap however for a snap up it would have a plate wide enough for inside straps on both ends. There is no pinch bolt, all the weight pulls the top down against the top of the frame and the strap bolts prevent the snap up from pulling out away from the frame. This creates a no drill situation. Pic is from the Reese SC hitch


However that method may cost more to make the snap up. Their solution of making the heavy gusseted brackets like you have may help stop the top of the snap up clamp from springing open however as you have proven the pinch bolt and frame crush is still an issue.

You mentioned the center bolt on the snapup, your right a through bolt may very well interfere with the pinch bolt. I'm still no fan of self tapping bolts. Mine does not have that upper center bolt. In your case with the adding the new frame plates you could tap the plate on the top center hole. However I myself would still through bolt the 2 lower holes.

As TT manufactures continue to push towards lighter frames to save weight, they should address this area. It is not that hard to add frame plates on day 1 as they know people have to use a WD hitch on these heavy TW campers. They are letting the WD hitch mfr deal with it.

John

JBarca wrote:

However the snap up on 1,200# and above can still fail due to the top springing open.

I think we've established that number is no more that 1,000# at this point....

JBarca wrote:

By bolting the snap up on that bending action that you so very well show in your sketch is not allowed to start.

Agreed. But, can you really through bolt the top hole. I think it almost lines up with the pinch bolt on the other side.


The most frustrating thing is that I spoke to Reese a few days before this all happened and they were supposed to send me rivnuts for the DC and snap-up mounts. I made it clear that I had lost trust in the self tapping screws. I wish I had just zipped one of the self tapping screws in the snap up mount while waiting.

Oh, and those rivnuts still haven't arrived....


Also, just to be clear, that drawing is not a bending action. The motion presented in that photo happens as soon as you snap up the bar. No excessive load, no turns, no bending. I think it's because the angle between the frame face and the top on the bracket is greater than 90 degrees.

The pinch bolt is parallel to the top of the bracket. So when you snug it down the top of the bracket is is flush to the top of the frame while the face of the bracket is not.

As soon as you snap up the bars, the bracket moves to other position where it's only touching at the pinch bolt, the top outside corner and the center of the tube. That's why I don't understand why this issue isn't more widespread.

I suspect the pinch bolt digs into the frame a little at that time and presents an even more concentrated point source ....

JBarca wrote:

The bolts if drilled at the top of the hole in the snap up prevents the downward force from springing open the top of the bracket and also prevents the bracket from starting to pivot outward to apply a point load to the bottom heel of the snap up putting a lot of pressure on thin tube frames.

So my understanding of excessive load on the tube when installed as shipped and according to the instructions is correct?

JBarca wrote:

It is not always "obvious" to everyone which way things should be.

Yes, hence my reference to the sticker.

mrekim wrote:
A light bulb just went off in my head:

Look at this photo from the Reese web site:




Note how the snap-up extends the entire height of the frame. That makes a lot of sense to me. the bottom of the snap-up is at a strong point on the frame, not one of the weakest.


Now this drawing of how these work on a 6" tube frame:





Is it reasonable to speculate that these snap-up brackets are simply not designed for 6" frames and that the original design took into account preventing stress on the middle of the frame and that somehow, with these larger frames, Reese may have simply dropped the ball?


[edit]
OK I found some pics (including my install instructions) with the snap up not reaching the bottom of the frame. I still don't understand how a huge portion of the load on the snap-up does not end up trying to fold the frame in though (without the bolt at the top).
[/edit]

Hi mrekim,

Sorry I have been away a bit and a lot has gone on since. A few things, that sales literature from the Reese site is a demo model. That is a 3" wide A frame. They show up on pop ups... It is not a real TT A frame that we are using.

5", 6" 8" A frame rails will have the issue of the snap up being supported by the frame center. It is not the A frame width issue, My channel iron 6" A frame rail has zero issues supporting the load pressed against it. And the set screw will bit directly to the inside web of the C channel. However the snap up on 1,200# and above can still fail due to the top springing open.

By bolting the snap up on that bending action that you so very well show in your sketch is not allowed to start. The bolts if drilled at the top of the hole in the snap up prevents the downward force from springing open the top of the bracket and also prevents the bracket from starting to pivot outward to apply a point load to the bottom heel of the snap up putting a lot of pressure on thin tube frames.

The Reese snapup bracket is very simailr to a C clamp setup and not a really great one at that. Have you ever sprung a C clamp before using one too small for the weight it has pulling on it? Same thing happens with the snap up.

I'm going to dig for a pic for you to help show the moment arm load effect of the chain on the snap up. This may add some help to the good discussion ongoing. I'll be back in a bit.

Thanks

John

PS. thanks for passing on the comments from Reese on the discontinuing of the bent angle chain plate. Yup, I suspected that folks were putting it on backwards and then really creating a problem factored into the equation. Sort of like this. I helped another bud with his, he pulled out the self tapping screws in his tube frame going around a corner. And the chain plate being on wrong did not help it. He was also into a corner radius issue.


See the other side, look you can see the bottom is bent some even if this side is turned.


It is not always "obvious" to everyone which way things should be.

buzzard616 wrote:
Having read the whole string I am concerned that NOBODY has suggested that many of your clearance and binding issues would be rectified by switching to a bent bar hitch for your deep TT frame.



The frame on the TT in the photo is nowhere near as deep as yours but you can see that there would be nothin' but air between the bars and the frame.

Hi Blizzard,

Since mrekim did not have the Reese round bar hitch head the issues associated with that style hitch when using a DC have not been discussed.

While the Reese round bar hitch head has some frame clearance going for it, it has other issues far beyond those of the trunnion bar hitch. The wost being the fact that when used on the DC, many users cannot get the WD set correct on the truck as they run out of hitch head tilt.

See this pic.


That hitch head is tilted all the way back to the TT. There are 5 usable positions of head tilt. 2 positions tilt the ball "towards" the truck, 3deg and 7 deg, the 3rd position is almost straight up. The last 2 positions are towards the TT. One at ~ 3 degree the other at ~ 7 degrees.

When using the DC you need to establish the correct chain clearance near the DC arm. In mrekim's case, he setup on 6 links under tension to create proper clearance. Then he tilts the hitch head to gain the correct WD on the truck. The Reese HP trunnion bar head can tilt 14 degrees towards the TT in fine increment from the serrated washer adjustment.

The Reese round bar head runs out of usable adjustment with those 2 rear tilt positions at 7 degrees. Many forum users have started with the round bar to later, sell it and buy the trunnion bar hitch to get the WD correct. When the TW of the camper comes close to the round bar ratings the problem is even more aggravated. If you have say 1,200# WD bars on a 800# TW, then you may get by and it work. Not so when you start getting closer to the 1,200 and need more head tilt.

It is not a round bar issue, it is the Reese round bar head tilt system with the hex washer used with the DC. A older drawtite head with washer added/subtracted tilt can work.

Every hitch has pro's and con's. There is no perfect one size fits all. In this case, the trunnion bar clearance can be obtained on the trunnion bar head with the correct tow ball and hitch adjustment. It is not that the Reese round bar hitch is bad, it just does not fit this application well.

And as mrekim stated, round bar or trunnion bar does not change the snap up issues associated with thin tube style A frame rails.

Just pointing out what may not be so obvious so folks following along can see all the conditions when they get a new hitch.

John