Setting up an under frame mount coupler with WD setup

[Frozen001]

So if you read my other post about the hitch failure (Hitch Failure), you will see I have to help my father set up the WD setup for is new trailer. The trailer has an under frame mount hitch, so when the dealer set it up, getting the chains to reach the snap up brackets is tough. I know there are some pretty knowledgeable people on here about setting these WD hitches up. I am looking for some pointers.

[Frozen001]

campigloo wrote:
I'm no expert, but the tilt on that hitch really gives me the creeps. Any hitch I have seen or used does not change the angle of the receiver. The shank on the hitch stays straight with the rest of the truck. The only angle that changes is the head that is intentionally adjustable. Something looks bent to me.

Part of that is the angle, and the truck is not totally level. Also that photo was with too much tension causing the front too low. And again the shank has slop inside the receiver tube. It is pretty normal at least now compared to in the past. The tube has just as much slop as my 2500HD OEM had and the Curt XD I replaced it with. It appears to be the new norm. I remember when there was much less in the receiver tubes.

I will post some photos when we take it to a level parking lot, and I am sure it will not look as bad as this shot.

[campigloo]

I'm no expert, but the tilt on that hitch really gives me the creeps. Any hitch I have seen or used does not change the angle of the receiver. The shank on the hitch stays straight with the rest of the truck. The only angle that changes is the head that is intentionally adjustable. Something looks bent to me.

[Frozen001]

Campin LI wrote:

Frozen001 wrote:

My concern with the head tilt is in relation the ball axis has with level ground.

That angle makes no difference.

OK then if that is the case he has a lot of room to reduce the tension on it. The head original head tilt that resulted in too much transfer was using the Reese directions to set the tilt. (set by the height of the bar ends from ground on page two of the directs).

One area we both noted is that the ball of the newer trunion heads sits about 3/4"-1" above the top of the trunion sockets. We both felt if that was level or at lease closer, some of the problems with the bottom mount couplers could be reduced. This would bring the bars closer to the frame.

[Campin_LI]

Frozen001 wrote:

My concern with the head tilt is in relation the ball axis has with level ground.

That angle makes no difference.

[Frozen001]

Campin LI wrote:
I don't think you understand what you need to do. The angle the hitch head makes with the truck means nothing. If you tilt the head forward toward the truck, you could take up a chain link. I think you are lifting the back of your truck up too high, especially if the front is down 1". The front suspension may be on the bump stops too. I think you should keep tilting the head forward toward the truck until the front of your truck is at unhitched height or slightly higher. Then move hitch head up or down on the shank until the trailer is level. Keep re-adjusting until it is right. The coupler mount really has no bearing on your setup.

You were already referred to the sticky on setup to read. You need to have a basic understanding of what to do before you start. Good luck.

You are not fully reading my post. We did take it up one notch and it retuned the front unleveled height, which is the target from every where I have read.

My concern with the head tilt is in relation the ball axis has with level ground.

Lets get this straight.

1) Lets call 90 degrees the point where if you draw a line along the axis of the hitch ball the point where that line is perpendicular to level ground. We will call a ball tilted toward the trailer to have a pitch of greater than 90 degrees. A tilt toward the truck we will call less than 90 degrees. Some crude images to illustrate this.



The greater than 90 degree angle is what I have typically seen. In this case we are looking at the ball angle to be less than 90 degrees. (the angle is in relation to level ground) Is this a valid configuration? I believe the ball is resulting in the less than 90 degree angle because of the slop in shank has in the receiver tube.

[Campin_LI]

I don't think you understand what you need to do. The angle the hitch head makes with the truck means nothing. If you tilt the head forward toward the truck, you could take up a chain link. I think you are lifting the back of your truck up too high, especially if the front is down 1". The front suspension may be on the bump stops too. I think you should keep tilting the head forward toward the truck until the front of your truck is at unhitched height or slightly higher. Then move hitch head up or down on the shank until the trailer is level. Keep re-adjusting until it is right. The coupler mount really has no bearing on your setup.

You were already referred to the sticky on setup to read. You need to have a basic understanding of what to do before you start. Good luck.

[gmw_photos]

Looks like it's winding it up alright. If it was mine I'd put a good receiver on it if I were going tow something that heavy with that stout of WD bars.

[Mvander]

That receiver looks to be pointing upward to me. Could be the pic but i would give that receiver a thurough inspection. The shank looks upside down too. If you fliped it you could tilt the head back and get the bars at the correct angle and gain some height adjustment where you need it.

[Frozen001]

So last night we set it up per the reese instructions. Here is what we noted:

1) The hitch head as setup by the dealer was 4" lower than what reese instructs.
2) The slop between the 2" receiver tube and the 2" shank makes setting these things up difficult
3) We did this in his driveway which may not be 100% level. This weekend we are going to bring it out to a flat parking lot to verify the setup. I was not present when he made a final adjustment of tilting the head forward 1 tooth. Prior to me leaving the setup resulted in the front of the truck being almost 1" lower that unloaded height, and the trailer nose high. By moving the 1 tooth, he said he ended up almot exactly at the unloaded height. That said, I am a bit consered on how the angle of the head ended up. Attached it a photo of the setup as it was with the truck frong 1" lower than it's unloaded height.





I drew some lines on it using MS paint to attempt to highlight the angles. At this point the head looks like the ball is straight up and down. My fear is that by moving the head tilt 1 tooth less the tilt is now toward the truck. When we look at it this weekend I will have more information. If this is the case, I honestly thing my prefered solution would be a longer chain.

Also anyone know how to tell if his OEM receiver is flexing? I am concerned about that as well.

Thanks

Lou

Moderator edit to re-size picture to forum limit of 640px maximum width.

[BarneyS]

That thread that I linked to earlier discusses that problem. Many receivers are either too big or not strong enough and wind up when under load. You just have to tilt some more to compensate or find a way to reinforce the hitch receiver to it doesn't bend as much. Many folks (me included) replace the factory receiver with an aftermarket one that is built much stronger. Many mid 2000 GM vehicles were notorious for this and some others also.
Barney

[Frozen001]

BarneyS wrote:
I am not so sure you really do understand the typical setup as you stated because of your last statement. What do you mean by " negative tilt"? The hitch head should tilt back towards the trailer and should not move at all when the bars are drawn up. It needs to be in a fixed postion. That position is determined by the amount of weight distribution needed when the bars are at the proper angle and the number of chain links needed under tension to achieve proper weight distribution.

Barney

The negative tilt I am talking about is what happened when the dealer set it up. They positioned the head by placing it on the truck, and the adjusting the tilt until it was level. Then due to the slop between the 2" shank and the 2" receiver tube when the bars were put under tension the shank went from resting in the bottom of the receiver tube to now pressing on the top of the receiver tube. That movement cause the head to go from level to being tilted toward the truck. I know this is wrong, but was just verifying that it is wrong. If you look at the photo I posted of it hitched to the truck you can see this "negative" tilt. I told the dealer it was wrong but I think at this point after putting together two WD setup on the same combination they had had enough, and said it is fine. I just said I would fix it later then after we got it home.

[BarneyS]

Frozen001 wrote:
I totally understand the typical setup, but with his trailer having the coupler on the bottom of the frame and I am wondering if being on the last or second to last link is a problem since I thin that is were it is going to fall. Also just to be sure, the ball had should not have "negative tilt" correct, the farthest forward should be level under tension correct?

Many on here have bottom mount couplers and have no problems setting up their WD hitch. There is no reason not to use the last link in the chain as it is just as strong as any other link.

I am not so sure you really do understand the typical setup as you stated because of your last statement. What do you mean by " negative tilt"? The hitch head should tilt back towards the trailer and should not move at all when the bars are drawn up. It needs to be in a fixed postion. That position is determined by the amount of weight distribution needed when the bars are at the proper angle and the number of chain links needed under tension to achieve proper weight distribution.

I suggest you take a long look at this thread which will help you. About 2/3 of the way down the page there is a picture and post about member Turk2500's trailer who has the same type low mount coupler that you have. Take a look at his setup, but also study that whole post including the provided links. I think that thread will give you a lot of information to help you get your fathers trailer set up properly
Barney

[Lspangler]

Last link is just as strong as the first link. Chain length makes no difference

I also have a windjammer with the under mount coupler. On my propride hitch I use the last hole in the link bar

On his hitch you want the head tilt and chain length adjusted so the spring bars are about parallel to the frame when the front end is at unloaded height and a slight downward tilt on the head. You may need to add or remove washers adjusting tilt and then add or remove chain links or restore front axle weight.

With the under mount coupler you will need longer chains than a similar setup on a top mount coupler to get the bars parallel.

Linc

[Frozen001]

I totally understand the typical setup, but with his trailer having the coupler on the bottom of the frame and I am wondering if being on the last or second to last link is a problem since I thin that is were it is going to fall. Also just to be sure, the ball had should not have "negative tilt" correct, the farthest forward should be level under tension correct?