So trip before last with a full car I noticed a mild shake in the steering wheel while going down a pretty good hill but not braking.

Noticed a missing weight but didn't address it, I needed new tires anyways, so I got new tires, had alignment checked etc.

Since the new tires I felt it once more with a full car going down a pretty good hill but not braking.

Over the weekend I was on another trip with a full car and felt a stronger shake in the steering wheel on a lesser downhill but only at 80 mph. Slow down a little and it went away. But I swear I ran the same section of road a few weeks ago with no one in the back seat and never felt a thing.

It's almost like it only happens with 5 people in the car and only while going somewhat downhill. Like it shakes after the weight transfers forward when speeding along 80 mph.

I'll check air pressures, look for missing wheel weights, basic stuff, and I do understand things are not always perfect smooth at 80 mph. But this last time was enough to make me slow down. Pretty sketchy feeling. So what else should I look at considering the above? Doesn't shake at 80 mph on flat to slight uphill incline, only if slightly downhill. Makes me think tire pressures in the front or maybe something suspension related like time for new shocks and struts but IDK.

 

These cars are all time awd if my mind serves me correctly. Are you accelerating down the hill or letting the transmission regulate speed so to speak. When was the transfercase fluid, differential fluid, transmission fluid changed?

Usually suspension issues manifest at all speeds above a certain speed.

Try changing the differential fluid if it hasnt been changed and repeat the process. Also monitor the indicator for where "power" is coming from the wheels in the on screen menu. Its the one showing 4 tires with bars beside them to indicate the power to each wheel i believe. Hope it helps

 

I'm still giving it some amount of gas, whatever it takes to maintain speed when it starts. It's not under engine braking or foot braking.

Fluids last changed the last time the service minder came up for it.

Yeah, it feels just like a tire out of balance, but in my experience that shakes at the given MPH continuously.

I did find air pressures to be out of whack though. I hope that's it but if it is I'll feel dumb cause all you gotta do is hold the middle button 3 seconds to see all the pressures. I thought the old left front tire had a slow leak but apparently it's the stem or wheel is leaky. I'll have to get it out to the interstate and see if that was it or not. I'll pull up the SH-AWD display while doing so too.

 

A couple possible culprits (though I think very unlikely) could be a wheel bearing or the driveshaft / half shafts.