7000 Miles Later… Every PROBLEM On Our New Momentum 395MT!

1 week ago
Chad

New RV, new stuff to break in, or just break! Our shakedown trip in the Grand Design Momentum 395MT has covered more than 7,000 miles so far, and we’re not done yet. Along the way, some things simply failed, a couple we broke ourselves, and a few were tweaks I made to head off problems before they started.

We’ve always shared the good, the bad, and the ugly on every RV we’ve owned or borrowed. This one is no different. And for the record: no matter who builds it or what it costs, a brand-new RV will have things break. If you make it 7,000 miles without a single issue, you have a bona fide miracle on your hands.

One big benefit of our partnership with Grand Design is the feedback loop. When something goes wrong, we pass it along, and they use it to build a better product. Several of the fixes below came out of exactly that process, including the very first one.

1. Roof and Front Cap Junction

Our 395MT has Grand Design’s new one-piece “worry-free” roof. There are no seams and no TPO or rubber membrane, just one solid piece. Grand Design has used this style of roof on other lines for a while, but ours was one of the very first Momentum builds to get it.

Being an early build came with one small issue: the spot where the front cap meets the roof. The original joint used screws covered with a black, EternaBond-style sealing tape. After a few weeks of travel, I climbed up and noticed some of those screws starting to push up against the tape.

The seal wasn’t broken, and no water had gotten in. But I could tell it was going to become a problem. I contacted Grand Design, and they sent out screws made specifically for this roof, each with a seal built into the head, plus more tape. I added extra screws where the joint was bowing up and sealed everything down.

A few weeks ago, we took the RV to Elkhart so Grand Design could address several items on this list. They’ve since changed how the front cap attaches to the one-piece roof, and the new connection looks much more solid. They took the feedback and found a better way to do it.

2. Garage Ramp Sealant

This one isn’t a fix. It’s a precaution I’ve taken on every toy hauler we’ve owned. At the back of the garage, a metal plate sits where the garage floor meets the ramp.

Our 397, a 2018 model, wasn’t really designed to have the patio deck down in the rain. We did it anyway. Water got into the wood there, and we had to make repairs. So when we got our 410TH, I sealed that joint, and we never had an issue.

I did the same on the 395MT using Sikaflex 221. Grand Design told me it really isn’t necessary anymore. There’s now an automotive-grade seal under that plate, just like on the roof. Still, out of an abundance of caution, I sealed it anyway.

Fair warning: I’m terrible at caulking. I always use too much and end up with caulk on everything. I really should have taped it off first. But it’s functional, and it’ll keep the water out.

3. Lippert Titan Leveling System Not Leveling

You can be the judge on whether this one counts as broken. The 395MT doesn’t have Lippert’s OneControl. Instead, it has the Precision Plex system from Precision Circuits. It replaces the OneControl screen, which I always found frustratingly slow to respond.

The trade-off is that leveling no longer lives in an app or on the main screen. It’s only on the control box by the entry door. And I have a few beefs with the Lippert Titan Leveling System that can’t be fixed:

  • The PIN code can’t be changed. It’s the same on every system. FOREVER.
  • You can’t adjust the lock-screen timeout. Step away to set chocks, and you’ll need to re-enter the code.
  • Most importantly, it doesn’t actually level the RV.

Auto-level gets us close, around 0.1 or 0.2 degrees, then pauses for a few seconds. Then it jumps to zero and says “Good” without moving any jacks. Meanwhile, we’re still about an inch and a half low at the nose.

The LevelMate MAX Fix

You can feel it inside when your house isn’t level, even when it’s only slightly off. That matters even more for Tara, who deals with some vertigo. So I installed a LevelMate MAX, which can be mounted vertically at the front or rear of the RV.

Now I let auto-level get us close, then fine-tune the jacks manually until the LevelMate MAX confirms we’re level. Our older leveling system (Lippert Level-Up) nailed it every time, so I’m not sure why this one gives up early. If you have the Titan system, I’d love to hear how auto-level has worked for you.

4. Broken Closet Bar Mounts

This one also broke in our 410TH, and possibly in our 397, so I’ve passed the feedback along. The round brackets that hold the closet rods are plastic. With a full-time wardrobe hanging on them and plenty of rough roads, they eventually crack.

I replaced every one with metal brackets. They aren’t a perfect size match, but they don’t need to be. As long as they’re secure, the rods aren’t going anywhere, and they’ve held up well.

5. Squeaky Bathroom Faucet

Not broken, just a huge annoyance. The faucet in our main bathroom developed a loud squeak. Picture getting up at 2 a.m., trying to be quiet, and waking everyone the moment you turn on the water. The same faucet in the rear bath gets less use and never had the problem.

The fix was simple. Pull off the faucet knobs, and you’ll find a few rubber grommets inside. Coat them with plumber’s grease, put it back together, and it’s been silent ever since.

6. Entry Door Hitting the Doorframe

This is the first RV we’ve owned with a friction hinge on the entry door. It adds resistance when opening and closing. That way, the door won’t swing in the wind and doesn’t need an exterior hook to hold it open.

I have mixed feelings about it. I can see the appeal for folks who leave the door open a lot. But I miss giving the door that perfect swing and having it close on its own. With the friction hinge, you have to push it shut.

Ours developed a bigger problem. After talking with a few RV techs, I believe the hinge was pushing the door out just enough for the top corner to rub the frame. Closing it turned into a battle, and we had to slam it to get past that rub.

Grand Design fixed it during our Elkhart visit. Turns out, all they did was add some WD-40 to the hinges. I’d tried the same thing with a PTFE spray with no luck, so maybe WD-40 is better for this application. I’ve heard others have had this issue too. Do you like the friction hinge? Have you had trouble closing your door?

7. Broken Pantry Drawer

This one we broke ourselves. Our drive from California 49 to 120 was switchback after switchback, with constant side-to-side forces inside the RV. Somewhere along the way, the pantry door opened, and a drawer full of heavy cans slid all the way out. The impact knocked the drawer front almost completely off.

Grand Design said they’d never heard of this happening, and they use this pantry configuration in a lot of models. I couldn’t find anyone online with an issue this extreme either. I chalk it up to those crazy roads more than anything.

Luckily, the drawer wasn’t badly damaged. I pushed it back together, added supports with my nail gun, and repaired where the front attaches to the soft-close drawer slides.

Preventing a Repeat

Even before the drawer incident, the pantry door had swung open while driving and hit a light with the slide in. So I installed a magnetic child lock behind the door.

These are far better than the child locks I’d used before on our garage cabinet. They’re easy to install, screw in solidly, and use an actual hook rather than a slide-style catch. I liked them so much that I replaced all the locks on the garage cabinet too. If your pantry door has opened on the road, I’d like to hear about it.

8. Accent Wall Latch Loosening

This could have been a much bigger problem. The accent wall in the living area swings open to reveal storage behind it. There’s access to the TV cables, an outlet, and room to hang a Dyson-style stick vacuum. It’s a really cool feature.

But it’s a big, heavy wall on a large hinge on one side, with a single bar lock holding the other. The pin for that lock didn’t have solid backing, and it was working loose. If I didn’t address it, that wall was eventually going to swing open during travel and hit the slide.

The front side of the pin was screwed into solid material, but the back side wasn’t. I added anchor screws on the back side, and they’ve worked great. We passed this along to Grand Design, and they’ve since reinforced that area.

9. Garage Three-Season Wall Handle

If you’ve owned a toy hauler, you’ve probably had Lippert’s three-season doors. We’ve been through a few generations. Our 397 had the old-school version with plastic sheets attached by Velcro, which was a real mess. Our 410TH had glass panels. Much better, but they still left big gaps along the top and bottom.

Grand Design has now replaced all of that with a full RV wall. The entire wall opens up, and it has a built-in residential sliding glass door. It works like a normal door and keeps the bugs out. We really love it!

The issue was the handle that holds the wall closed. It’s a standard RV-style locking handle. The pin in the inside paddle came loose from all the jostling, and the handle fell off. I could have replaced it easily, but Grand Design took care of it during our Elkhart visit. Really no big deal, but I was stretching to get to 10 issues. 😎

10. Garage Water Leak

This last one got a little weird, mostly due to my own faulty troubleshooting. The first time heavy rain hit that side of the RV, I noticed small beads of water at the seam where the garage floor meets the wall on the driver’s side.

I worked through several rounds of troubleshooting and was convinced the garage window was the culprit. Grand Design sent a replacement window to us in Glacier, and a great mobile tech installed it. We leak tested it afterward, and it still leaked. 😳

The real source turned out to be the skirting along the edge of the RV. We sealed it with Sikaflex, and that stopped the leak. Very little water ever made it inside.

Grand Design hadn’t seen a leak in that spot before, so they wanted to find the root cause when we brought the RV in. They removed the skirt and found a gap in the sealant tape from when it was applied. They’ve since improved that installation process, and ours now has proper tape underneath.

Final Thoughts After 7,000 Miles

That’s everything I’ve fixed in our first 7,000 miles. Considering how many new features this RV is trying out, like the one-piece roof and its front cap junction, I’ve been really impressed with the build quality. We also really love this floor plan.

Have you run into any of these issues, or others? Let us know in the YouTube comments. In a future video, we’ll take a closer look at the Precision Plex system that replaced OneControl in this rig.

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