We bought out edge new in 2013.
always had separate winter wheel/studded snow package. The car has always been great in the snow.
It now has 135,000 miles and is nearing the end of its life (rust belt)

This recent snowstorm, the car felt very unstable in the snow over 25mph. AWD is working. it almost feels like the rear tires are turning faster than the front or the opposite. It climbs steep hills in the snow and feels stable on blacktop, so I don't think it is suspension related. Current studded snow tires are and performed great earlier this season.

Any ideas?

Thanks

 

Can we ask were the same tires on the vehicle all year round ?

The reason we ask, because with all wheel drive all tires must be the same manufacturer and same size circumference. If the tires are a different circumference, the system make no allowances for that and they don't pull quite the same.

 

Tire circumference is the same.

 

Is it possible there is a clutch pack or something that is going bad? I'm not familiar with these AWD systems.

 

Because I know you did not go out and measure the circumference, of each tire, how do you know that with out actually checking that?
Don't make the mistake of assuming anything until certain checks are done. This subject is critical for all wheel drive vehicles to function correctly.
It would help if you checked your owner's manual which should explain some of this..

 

Are you saying there could be a manufacturer defect and the tire is not the size that is molded on the side of the tire?

 

That is why I asked if the 4 tires were on the vehicle all year round.

We can't go by the size printed on the tire because they say one thing ,but wear differently.

There is a coupling that is supposed to manage this, but before going there we need to know the answer to if the 4 tires were on there all the time.
Sometimes folks put different tires on for the winter, don't know if you did that.
This is something most folks don't know about all wheel drive and should be explained in your owner's manual.

 

They are not on year-round. They are on their own wheels and all 4 get switched out from summer to winter. This year all 4 winter tires are new. maybe 2000 miles on them. I have been doing this since 2013 with this vehicle. This is the 3rd set of winter tires that have been on the winter rims.

 

To get further into the info needed, this will require a scan tool with a graphing function to observe just what info is being sent to the vehicle computer.
This will usually let the tech know which wheel(s) are having a problem or the signal not getting to where it is supposed to go.

Your best bet is to have a good shop that has the info, equip and training to diagnose the problem.

 

Thank you.