Is this normal

[Lazy D]

Many of you have helped me along as a new owner and I appreciate it.
I have something else to throw at you all. I added a Acculevel to my pin box.
Now I notice what can best be described as flexing. It may be completely normal I just don't know since this is my first 5th wheel. In the video you can see when I hit a dip in the road my level and pin box doesn't move, but the front cap seems to have a lot of bounce in it as you can see if you watch the horizontal white pin stripe right above the level.
Thanks in advance.

https://www.youtube.com/watch?v=SR_Jf-0KzMc

https://www.youtube.com/watch?v=cV11jrF9zOU

[Dayle1]

Some flexing is normal, but too much indicates a problem. Normally the amount of flex is measured at the king pin by how much it deflects between unhooked and hooked. However this is not ez to do given the truck's suspension movement. Dealers will measure it using a forklift, good would be 1/2 inch or less, anything over 3/4 inch is too much. You can measure it using a length of 6x6 post and a bottle jack. With the fiver wheels firmly blocked, raise the bottle jack til it just touches the bottom of the king pin. Note the extension. Then raise it til the foot pads on the landing gear just begin to lift and note the difference

There is a lot more flex in the steel frame than many people realize and the front cap is NOT attached to the frame, only to the sidewalls and the roof. If you have a front closet, the floor is attached to the steel frame, but the front wall is NOT. The floor will buckle up as the steel frame flexes. You didn't indicate your year or model number, but Cruisers were improved August, 2011.

[Lazy D]

I guess I need to add my signature line.
It's a 2013 Elevation 3612.

[Dayle1]

Here is a link to the repairs on my Cruiser, the 3rd picture is a Lippert frame drawing with the changes highlighted in yellow. The original frame notch was greater than was needed for the new front cap and resulted in too much flex, mine was like 1-1/2 inches. Immediately after this and several other Cruisers were repaired, Lippert and Crossroads made a permanent change to the frame that was almost identical to the fix.

Cruiser frame repair

[Lazy D]

After closer inspection I took these pictures. I don't remember the paint line looking like this before. The bolts are not obviously loose, but I'm thinking this is where it's flexing.

[fhenn]

It looks as if the holes are elongated (Not right) I would take it in and have it checked out, might be bad bolts all so

[Lazy D]

I've checked the bolts and they are TIGHT.
I also took a 4X4 and a jack and loaded weight on the pin measuring how much it flexed up under load. Measures out at 3/4". All that movement came from up inside the front cap.

[DavisK]

Lippert torque specs for grade 5 bolts:
1/2" - 75 ft-lbs
9/16" - 115 ft-lbs
5/8" - 150 ft-lbs
3/4" - 290 ft-lbs

[Lazy D]

That's another thing that bothers me. Why would they use grade 5 bolts. Grade 8 don't cost that much more. 2500 lbs of pressure on that area. Seems like it would make sense.

[Dayle1]

Originally Posted by Lazy D

I've checked the bolts and they are TIGHT.
I also took a 4X4 and a jack and loaded weight on the pin measuring how much it flexed up under load. Measures out at 3/4". All that movement came from up inside the front cap.

If the flex is occurring inside the cap, then cross members that hold the pin box are flexing. If you have a front closet, the plywood flooring is nailed directly to the steel cross members and as the crossmember flexes it pushes the plywood up but it may not return when unhooked. This can be visible using a strong flashlight looking into the front of the pin box.

[Chateau Duke To Go]

Originally Posted by Lazy D

That's another thing that bothers me. Why would they use grade 5 bolts. Grade 8 don't cost that much more. 2500 lbs of pressure on that area. Seems like it would make sense.

When I upgraded my OEM Lippert pin box to a MoyRide Ruber Pin box, I also upgraded to grade 8 bolts.

[Lazy D]

Originally Posted by Chateau Duke To Go

When I upgraded my OEM Lippert pin box to a MoyRide Ruber Pin box, I also upgraded to grade 8 bolts.

I have an appointment with the dealer on the 9th. I talked to them about going to grade 8 bolts. I told them I'd buy them if they will put them in. He said "No problem". Good folks to deal with. They are going to examine everything and see what's up.