Andersen Ultimate with Lippert 1621 HD Pin Box

[Searching_Ut]

Folks, I'd ask in this post that everyone please stick to factual, technical information type responses if any, and avoid emotional responses, or the personal attacks which often seem to become the case in discussions about the Andersen Ultimate hitch.

As I posted earlier, in a post the moderator had to rightfully lock, the Pin box base plate on my 2016 Bighorn fifth wheel was bent by the set screws on the Kingpin adapter for my Andersen Ultimate hitch. I posted photos in that post. I had addressed the issue with my dealer, and they said "that happens with that hitch", and said it wasn't an issue they would address claiming Andersen said it was not a problem. I had difficulty accepting this second hand information and went to Andersen for their response, evidently initially having e-mail issues in getting their response, which follows:

....................................

"Here's the response I sent previously. Also I spoke to my technical support again today and they are going to go ahead and send that spacer out so, you should see that within a couple days. Just be careful not to put it over any of the set screws. I apologize for the inconvenience.

Lippert used a thinner material to make the pin box is made out of on this particular model, and that has allowed this type of bending. You can put a spacer in and tighten it up. If you'd like we can send you a spacer. This will increase surface area around the pinbox to prevent that from happening any more.
As far as the intentations in the truck bed, can you please send some pictures of both the bed & base? If you're using the older style Ultimate, we can swap it out for newer base as we did have a few problems with that.
Thanks for your help. Have a great afternoon"

............................................

The pin box in question is a Lippert, model LIPP1621 HD, GVRW 18,000 lbs. and it is installed on a fifth wheel with a dry weight of 12,084lbs, dry pin weight approximately 2500lbs, GVWR of 15,500 My understaning is that this is one of the most common pin boxes currently being put on Lippert frames, so if you're using an Andersen Ultimate on a newer fifth wheel trailer with a Lippert 1621 pin box you might want to keep an eye on it and contact Andersen for spacers if you start having problems.

Again, I'd like to request this posting stay informational, factual, or at least keep opinions on the design of a technical nature, avoiding personal attacks, or emotional responses. For once I'd like to see an Andersen Hitch posting not become a burden on the moderators.

[Searching_Ut]

johndeerefarmer wrote:
I find three different Lippert 1621 pin boxes. They are rated at 15.5k, 18k and 21k. Shipping weights are 100, 105 and 115 lbs. Obviously heavier due to more and/or thicker steel
From what I can figure out the 1621 is 15.5k and the HD comes in either 18k or 21k.

So my question for the OP is- if your HD version of the 1621 pin box has issues, it looks like the standard 1621 which is very common on fivers would have major failures with the Andersen hitch. Yours is the first issue that I have heard of and you have the HD version.
So this makes me wonder if there is some other explanation?

When I first started looking in to this I thought based on internet reviews etc that the hitch is pretty much trouble free. Once I started having problems and talking to folks, I'm not so sure. My Dealer was aware of the issue, considered it to be normal wear with this hitch. Once I started looking in the storage lot etc I personally found one other pin box being deformed, although not as much as mine. It wasn't a lippert. As far as the metal used in the pin box, I'm not sure it varies much if at all in the base plate. My 18k lippert, and 21k Reese fifth airborne I replaced it with both measure the same with calipers as far as steel thickness in the base plate, but do vary in the thickness of the metal thickness in other areas. Finally, I've since talked with two individuals who quit using their Andersen hitches because of issues, and of course Andersen was aware of the potential and had shims already made up and ready to ship if required, so it's hard to say how common the issues may be. It's safe to say not unheard of, but anything mechanical can fail, and I have no idea what the fail rate is.

In trying to figure out why mine failed while the majority of the ones I see haven't, all I can figure is it might have to do with my towing more in the mountains than most. Downhill though the mountains where the engine brake isn't enough and you have to brake in the corners with the Ram brake controller resulting in the truck taking more of the braking load than desirable probably puts more stress on the pin box than anything else I do. The fact I had to put mine on with the pin forward of the ball instead of ball forward of pin might come in to play also, although I'm not sure why it would. Just speculating, and in the end for me it doesn't really matter as I'm using a traditional hitch now.

[johndeerefarmer]

I find three different Lippert 1621 pin boxes. They are rated at 15.5k, 18k and 21k. Shipping weights are 100, 105 and 115 lbs. Obviously heavier due to more and/or thicker steel
From what I can figure out the 1621 is 15.5k and the HD comes in either 18k or 21k.

So my question for the OP is- if your HD version of the 1621 pin box has issues, it looks like the standard 1621 which is very common on fivers would have major failures with the Andersen hitch. Yours is the first issue that I have heard of and you have the HD version.
So this makes me wonder if there is some other explanation?

[Me_Again]

Searching_Ut wrote:

Me Again wrote:

Searching_Ut wrote:
As you know, the bighorns themselves set fairly high up, and there isn't much I could do to raise the trailer itself easily.

We have similar trucks and my Big Horn is a larger model. It is pretty level. There is a mod you can do to the rear springs by moving the spacer to the other side of the spring pack. It creates a bit of a problem with the removal of the pin/bolts in the disc brakes, however that does not have to be done that often. Chris

We went with the 3270 bighorn as it was the best compromise we could find between what the DW likes and wants, and what I prefer. I like forest service type campgrounds, boondocking etc. where small is great. The wife would prefer something 3000 square feet or larger 🙂 She has decided this rig works for her though so we're getting good use out of it

As for lowering the truck, I'll have to look into that more. I have the factory air suspension in the rear, so it doesn't drop at all when I hook up other than an inch or so if I select the alternate trailer height setting. The air bags will probably complicate things. Initially I was only slightly nose high. Unfortunately, the new pin box raises things a couple inches, it's not exactly the same as the 1621 dimension wise. I'm currently looking for a good trailer shop to install a hitch on the back of the bighorn so I can tow my side by side. Maybe I'll explore options on raising the trailer a couple inches, but I'll have to watch total height being as how I'm already over 13ft.

OK, you did not say factory air earlier. I would talk to B&W about short vertical arms for the hitch. They have to have had requests for that. Someone posted that the flat bed hitch is shorter.

Looking at pictures of the verticals(pivit arms) in my RVK3270 they look shorter than the RVK3600 vertical parts. I measured mine for you, 13.25" from the bottom to the top of the rubber piece.

I have the factory pucks, Demo picture frame and RVK3270 manual slider. Chris

[Searching_Ut]

Me Again wrote:

Searching_Ut wrote:
As you know, the bighorns themselves set fairly high up, and there isn't much I could do to raise the trailer itself easily.

We have similar trucks and my Big Horn is a larger model. It is pretty level. There is a mod you can do to the rear springs by moving the spacer to the other side of the spring pack. It creates a bit of a problem with the removal of the pin/bolts in the disc brakes, however that does not have to be done that often. Chris

We went with the 3270 bighorn as it was the best compromise we could find between what the DW likes and wants, and what I prefer. I like forest service type campgrounds, boondocking etc. where small is great. The wife would prefer something 3000 square feet or larger 🙂 She has decided this rig works for her though so we're getting good use out of it

As for lowering the truck, I'll have to look into that more. I have the factory air suspension in the rear, so it doesn't drop at all when I hook up other than an inch or so if I select the alternate trailer height setting. The air bags will probably complicate things. Initially I was only slightly nose high. Unfortunately, the new pin box raises things a couple inches, it's not exactly the same as the 1621 dimension wise. I'm currently looking for a good trailer shop to install a hitch on the back of the bighorn so I can tow my side by side. Maybe I'll explore options on raising the trailer a couple inches, but I'll have to watch total height being as how I'm already over 13ft.

[Me_Again]

Searching_Ut wrote:
As you know, the bighorns themselves set fairly high up, and there isn't much I could do to raise the trailer itself easily.

We have similar trucks and my Big Horn is a larger model. It is pretty level. There is a mod you can do to the rear springs by moving the spacer to the other side of the spring pack. It creates a bit of a problem with the removal of the pin/bolts in the disc brakes, however that does not have to be done that often. Chris

[Searching_Ut]

Me Again wrote:

Searching_Ut wrote:
In using the Andersen ultimate hitch adapter I put loads on the pin box that it wasn't designed to handle.

I believe I covered that issue earlier in the thread. 1000's in use and not having issues when used as designed. Chris

You did indeed, and in several ways, similar observations have been made by many for quite some time. At the same time, many are quite pleased with there Ultimate hitch, and with luck things will remain that way for them.

I'm actually quite pleased with my new setup of a 5th airborne and B&W hitch. So far I've only driven it 2500 miles, much of it freeway which really doesn't count but it tows a lot smoother than before due to the airbag/shock and the hitch is quicker and easier to use. I'm quite pleased with how smooth, quiet and solid my new hitch is. If anything, it's overbuilt. The only downside, other than a pain to install due to the weight is that while I was about 2 inches higher in the nose than the tail before, now it's about 5 inches of difference. I have the pin box adjusted as far up as it can go, and the hitch set as low as it can go. I have about 8 inches clearance on the bed rails so if I have some room to play with there if I had a little more adjustment available. As you know, the bighorns themselves set fairly high up, and there isn't much I could do to raise the trailer itself easily.

[Me_Again]

Searching_Ut wrote:
In using the Andersen ultimate hitch adapter I put loads on the pin box that it wasn't designed to handle.

I believe I covered that issue earlier in the thread. 1000's in use and not having issues when used as designed. Chris

[Searching_Ut]

On the 1621HD, you can't look down the inside of the pin box from the back like that. There is a metal plate towards the bottom, much like the one you can see in your photo other than it goes from top to bottom, side to side of the whole pin box frame interior. From what I could see of the internal brace with an inspection camera it looks just like the U brace in the photo, which I suspect is welded to the aft plate in the pin box, but I can't verify. There is also a V piece of steel welded into the aft portion of the box that runs from where the pin box bolts to the trailer frame to the front plate in the pin box. The weld that you can see in the photo I posted of my pin box where the crappy weld goes side to side is where the plate filling the interior of the pin box is.

As for why the pin box got bent it seems pretty simple. In using the Andersen ultimate hitch adapter I put loads on the pin box that it wasn't designed to handle.

[rhagfo]

Well the discussion is why the lippert 1621 pin box bent.


Well, the design is to be both strong and light, in this picture of the interior of my 1621, you can see the U shaped pin reinforcement and the angle iron cross member at the back.
The bottom plate is likely about 1/8" thick.

[Searching_Ut]

minnow wrote:
So the spacer fills in the gap between the underside of the kingpin and the top of the aluminum adapter ? The set screws would then press against the spacer instead of the underside of the kingpin ? Do I have that right ?

The shim they sent me is a 2 inch by 4 inch quarter inch thick piece of aluminum stock with a piece of double backed sticky tape on it to hold it to the base of the pin box adapter. The only instruction are the e-mail I cut and pasted at the start of this post. The guidance is to not place it under the set screws. I think it would have worked had it been part of the original design and installed prior to the damage. The shim is just the right thickness to fill the gap between the adapter and the base plate of the pin box. Had something like this been installed under the adapter directly above the ball socket It would have ended up taking the bulk of the load and spreading it over a 2X4 square inch of the base plate rather than the ends of the two taper ended set screws.

I tried to look at the inside of the pin box with an inspection camera going through the hole for the pin box cover fwd mount screws but couldn't tell for sure how the cross brace for the pin is installed. I could only see a small part of it at a time, but all the welds looked pretty good. The back of the pin isn't a rounded base plate like the photo posted by WTP-GC, but appeared more like a long v, or rounded type brace. I'd need to cut the box open to tell for sure, which I may do some day just out of curiosity. From what I could see the baseplate isn't braced at all for a load the way I ended up applying it with the Andersen Adapter.

[minnow]

So the spacer fills in the gap between the underside of the kingpin and the top of the aluminum adapter ? The set screws would then press against the spacer instead of the underside of the kingpin ? Do I have that right ?

[Searching_Ut]

WTP-GC wrote:

Searching_Ut wrote:
When I have access to a computor I'll post photos but a fifth wheels weight is carried by the fat base of the pin box riding on the flat portion of the hitch. I don't think there are any oem pin boxes with a raised round base. With the andersen hitch adapter none of the vertical load is carried by the pin. The pin weight is all carried by two of the set screws which ride directly on the pin box base plate.

The raised round base would be on the inside of the pin box. There should either be the raised round base or some sort of cross member support. I don't know how they make the 1621HD, but the standard 1621 has a cross member attached to the kingpin on the inside. The Mor-Ryde pin box I use has the rounded base, and the set screws are within the footprint of this base. It would take a major failure in order for the adapter to cause this kind of damage on the Mor-Ryde.

The kingpin itself (just the lower connecting part) cannot be connected to the plate in that small 2" diameter area. That would be an extremely weak connection.

In your other thread, you showed that the kingpin had skewed. Could this be because a weld on the interior attachment came loose, resulting in a complete loss of strength? As I said, a lot might be learned by getting a look on the inside.

The plate did deform enough the pin is skewed. I'll run my inspection camera on the inside when I get a chance. It's worth a look out of curiosity as given the weld quality it's quite possible a weld failed.

[BB_TX]

Think about the forces involved. When used as designed, the weight on the pin box is distributed across a large flat pin box plate sitting on a large flat hitch plate centered around the king pin. When the adapter is installed, the weight is now distributed across a small adapter, significantly increasing the pounds per square inch weight factor, centered several inches offset from the king pin, and centered more toward the middle of the pin box plate rather than evenly distributed across the entire flat surface. Only surprise is that there have not been more failures.

Things are designed for a specific purpose, not for the possibility that some unknown after market manufacturer may someday make some as yet unknown adapter, of some unknown design, that will alter the stress characteristics in some as yet indefinable way. It just don't work like that.

[WTP-GC]

Searching_Ut wrote:
When I have access to a computor I'll post photos but a fifth wheels weight is carried by the fat base of the pin box riding on the flat portion of the hitch. I don't think there are any oem pin boxes with a raised round base. With the andersen hitch adapter none of the vertical load is carried by the pin. The pin weight is all carried by two of the set screws which ride directly on the pin box base plate.

The raised round base would be on the inside of the pin box. There should either be the raised round base or some sort of cross member support. I don't know how they make the 1621HD, but the standard 1621 has a cross member attached to the kingpin on the inside. The Mor-Ryde pin box I use has the rounded base, and the set screws are within the footprint of this base. It would take a major failure in order for the adapter to cause this kind of damage on the Mor-Ryde.

The kingpin itself (just the lower connecting part) cannot be connected to the plate in that small 2" diameter area. That would be an extremely weak connection.

In your other thread, you showed that the kingpin had skewed. Could this be because a weld on the interior attachment came loose, resulting in a complete loss of strength? As I said, a lot might be learned by getting a look on the inside.