Car shakes at high speeds

maybe axle shafts? start with alignment, tire balancing, cv joints then axle.

how many miles on her?

 

that could be a slightly bent frame, are the tires wearing evenly?

 

Lots of different possibilities....a couple that have potentially fatal consequences, one that springs to mind is a tire starting to separate.

I would have it checked by a reputable shop, quickly -- like immediately.

I HAVE heard of some people in backwards sorts of unfriendly areas such as rural Oregon who have rotated tires in such cases to see if that makes any difference, thus narrowing down the likely source of the issue. Of course, I would never do that -----well, at least not anymore. Saving some bucks is not worth the possible "human cost."
kris

 

Did you replace that part or did someone else?

 

Yes. The mount in the picture appears to have been previously replaced as there are markings indicating such.

Though hard to tell from those photos, the passenger tire might be wearing differently. Have you tried moving the passenger wheel over to the drivers side to see if the problem follows, if it does then I would try balancing the wheel next.

 

Not good.
You should get that fixed........before a wheel locks up or falls off.
Seriously.

 

Have you tried rotating the tires yet?

 

it sounds like you have a broken strut mount, but it's hard to diagnose these things online. a suspension shop should be able to give you an inspection and find the cause. You can remove the lower engine mount and fill the rubber section with polyurethane glue, I did this and it made a huge difference in stiffness. Lots of videos on youtube how to do that.

 

Could the motor mount even make the dashboard shake at 70 mph?

Have you tried rotating the tires yet?

 

it could, if the tire is not balanced properly and starts shaking, then other parts of the car not properly damped will also do the same. Sounds like something is definitely loose if torque from the engine is causing a thump.

Another simple test is with the hood open, apply the brake and gas at the same time in D, then do it again in reverse. Have a friend look under the hood and see what is moving.

 

With some Prius models, if you push the gas while the brake is applied, what happens is exactly NOTHING.

 

if that's the case you can set the parking brake and do the same maneuver. Just don't stand in front of the car in case it lets go.

 

The thumping could be bad ball joints. I had the same symptoms on my older minivan and wound up replacing the lower control arm assemblies. Look under and see if there is alot of play in that area.

 

Instead of guessing take it to a tire store for a free suspension check. A good front end guy will find that fast.

I can see the tires are done you need tires those will be terrible in the rain. Looks a like a really cheap tire to begin with.

Not sure why your looking for a poly motor mount you wont beat the metal one that's in there looks like they replaced that part from a junkyard by the labeling which means it took a really hard hit to the front end if that part was damaged. Probably never had the front end aligned after the butch I mean assembly job.