Frame flex

[Seismic4113]

Hello all,
Does anyone know the allowable tolerance for "frame flex/pin box flex" on the 4113?

 

[The Village Idiot]

Sorry. I do not. But obviously, this is a hot topic these days.

I'm curious why you ask? Is this just for keeping an eye on things or do you think you're having an issue?

We recently bought a 2024 4113. It's a huge reason we did not get a Momentum but I don't know if it's a Seismic concern yet. There are a whole lot more Momentums on the road versus Seismics. At least in our area.

 

[Seismic4113]

No issues with my 21 4113. My pin box only flexes about a 1/2". I haven't heard of any issues with Jayco 5ers.

 

[WFOracing]

Lippert 1621HD Frame flex

I have a 2018 Seismic 4212. Mostly love the thing but it's had some issues. 1) street side skin crack running from lower front corner of master bedroom slide down and forward to about 6" and growing until I arrested and patched it with 1/8" aluminum 6061 tooling plate, painted to match. I wet installed w/ epoxy, rivets, and screws. Doing fine after a season of towing.

Because the Seismic units use the same Lippert 1621HD frame as the GD Momentum I attribute my skin crack to frame flex (though not of the same magnitude as the GD's) w/ other likely factors.

2) forward cap separation at roof plywood. Upon investigation I found an inadequate amount of fasteners with short edge distance allowing fastener breakout and causing the cap to move forward by about 1.5". I added more fasteners in situ (couldn't/didn't want to relocate the cap).
Patched the gap, resealed.

I over stuffed my master closet which I think contributed to this.

I swapped out the MORYDE pin box this winter for a Gen-Y Executive torsion control unit. I'm hoping to greatly reduce the stresses, but haven't used it yet.

 

[atlantaM3]

You mean the Lippert 1621 pin box is the same, not the base frame, yes?

from what I understand there are differences in which pin box was used in the seismic line. And some were labelled wrong - mine was after validating with Lippert.

All that said, not aware that the base frame is the same as the GD units.

 

[atlantaM3]

No issues with my 21 4113. My pin box only flexes about a 1/2". I haven't heard of any issues with Jayco 5ers.

Ditto with my 2018 4113. Has not yet experienced this issue thankfully. Plenty of other stupid stuff, but not this one.

 

[WFOracing]

Seismic Frame flex

Let me apologize for stating above that the Lippert 1621HD frame on the Seismic is the same one used by Grand Design.

What I should have said is that the Seismic and the GD use the same Lippert 1621HD basic part no., but have peculiar differences per each manufacturer's specs.

I am not aware of Seismic frame failures anywhere near the magnitude of the Grand Design.

 

[christopherb66]

Yes Jayco does have frame flex/failure issues

I have a Seismic 4112, 2016 model. I remember seeing a small hairline crack in the fiberglass right after the warrantee expired. Didn't think anything of it.

I have posted some pictures. I have a video showing the flex is close to an inch. Too large to upload.

As you can see in the last picture, this is from a Lippert video on YouTube praising their frame strength.

Mine does not look like this at all. There are no solid pieces of metal tying the upper pin box frame to the lower I beam frame.

My guess is that a re-design was made for a reason.

The flex caused all the seals to fail in the front and water pretty must rotted out everything back to the garage doors.

Now what? Any suggestions?

Pictures included are stringers running side by side, there lacks any welds on the bottom of the king pin frame. If there were welds, it might have somewhat increased the tensile strength and minimize flexibility.

The Stringers running north/south to the kingpin are not even welded to the upper cross member which ties the upper and lower frame together.

Totally disgusted!! This has probably slowly been happening the more I used the unit.

I had an engineer look at the frame and he said the frame was designed to fail especially when there is very little weight in the rear. The frame to the kingpin in front of the wheels was not designed to absorb so much stress. The teeter totter effect.

I admit most of our long trips more than 300 miles we only took our kayaks and not our golf cart. A tremendous difference in weight.

 

[Sparksflyin]

I have 2017 4112 with crack starting in lower left of bedroom slide.
Anyone have any recommendations on who could do a good repair on them?
Any help appreciated

 

[WFOracing]

Jayco 4212 Stress Crack Repair

1/8" 6061 Tooling plate.

#8x 1 1/4 washer head wood screw fasteners

Fill crack with two-part JB Weld epoxy

Pre-pilot plate, apply remainder of epoxy to back side, and center over crack.

Apply Pli-bond or other sealant to fasteners

Install fasteners compete and ensure even squeezout of epoxy at edges. Wipe off excess with acetone soaked rag.

Paint and polish