My Class C Majestic is loud and all over the road!

Like Bryan said, weigh it. Corner weights (RF, LF, RR, LR) are best. If you can get those, set tire pressure on both sides according to the higher corner weight. Most of us can only get to a CAT Scale at a Truck Stop, and those give only Axle weight. If you go to one and have a toad, tow it onto the scales and you'll get its weight also.

And, again, if you need it aligned, go for 5.0L and 5.5R Caster. Make sure the front end isn't worn out. Both Bryan and I have renewed our Ford E-series front ends with takeoff parts from 4x4 conversion shops. Cheaper to replace with takeoff than to repair.

I wonder if your exhaust system is damaged. Leaking and/or jammed against the chassis. If pipe is against chassis or hangers are shot, you'll get noise inside. You'll also get noise if a "motor mount" is bad.

It'd help if you'd post Make/Year/Model of this coach. Also Miles on it and Wheelbase, plus Front/Rear Weights if you've been to a scale.

My son and I took a RV for a test drive and it was so loud we could not hear each other. When we got back to the dealer we found out that the door was warped and the windows were not closing properly. A year later took my Majestic 19G for its test drive and I was shocked by how quiet it was. bought it and when I left the lot after buying it I was 10 minutes away from the dealer and the noise got really bad. Took me half an hour to find a safe place to pull over and I was almost in tears it was so loud. Checked the windows, vents, door and everything seemed good. Then I decided to open and close EVERYTHING. Vents were good, door was fine but the window behind the drivers seat was open the slightest. Cleaned the track as best I could and slide it closed and the noise was gone. It still comes open occasionally and I laugh about it now.

I also added carpet and underlay for warmth but it sure cuts down on road noise as well!

That't definitely not a normal sound level. That's about the same as a gas lawnmower, and actually would require hearing protection if you were exposed to that level for 8 hours at work.

Is the engine cover/doghouse fully seated? The side latches need to be secured before the bottom latches.

Is the exhaust system intact?


And yes, for the handling issue, check tire pressure first, and adjust according to load. Front tires should not be fully inflated. Door tag is a good start but tire pressure vs load charts are even better. Besides that, have the front end inspected for wear, and make sure it's set to max caster (5-5.5 degrees). Also, make sure it isn't loaded to take too much weight off the front axle.

I don't know how accurate a Decibel App is compared to a Decibel Meter.
Either way, the noise is too high in your rig. Can you determine where or what the sound is coming from while traveling?
Is it the things bouncing inside the house, exhaust, wind noise, etc.?
If you can pinpoint the source, maybe you can make some improvements or adjustments.
But, as donn0128 indicated, it may just be the nature of the beast.

Sometimes the noise is associated with lousy roads - in my area the noise difference between newly paved road and old one is dramatic.

I am guessing you have a Ford chassis? First, check air pressure in your tires. Then take it to a real alignment shop and have it setup. Then look at shocks.
As for noise? Not much you can do. A full undercoat might help some. Most of the noise is stuff you cannot control Im guessing. Unless you start walking around while someone else is driving and start identifying squeeks, and rattles you are basicslly SOL.