QX4 shakes under hard acceleration in 1st gear...

[ricehead]

2002 QX4 4x4, 60k miles

It is otherwise smooth. When accelerating from a stop in 2wd, and giving it hard throttle there is a subtle shaking in the car, not really the steering wheel, but the whole car.

Any ideas why this would happen? Only thing I could think of is a warped driveshaft - is this common?

[driverdriver]

A few reasons:

unbalanced tires? bad ignition coil? Blocked air intake or malfunctioning MAF?

[NISTECH]

this sounds like a driveshaft problem. possible u-joints I would say carrier but the R50b unibody doesnt have a carrier.

[driverdriver]

When you crank the wheels left or right while in 4X4 high do you get resistance, kickback or vibration(try it on even dry pavement) while driving? If so its your U-joints. They eventually go.

[ricehead]

The mechanics are thinking it's a transmission mount problem, but i'm bringing it into a nissan dealer today for a second opinion

thanks for suggestions, probably the U-joints - seems unanimous

[ARKQX33V6]

When you crank the wheels left or right while in 4X4 high do you get resistance, kickback or vibration(try it on even dry pavement) while driving? If so its your U-joints. They eventually go.

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Sounds like limited slip diff is doing its job.

[ARKQX33V6]

In 2 WD hard accel---spark plugs, advance mechanism is sticking or sluggish. Or transmission 1st is by-passing into 2nd or even 3rd

[Densetsu]

Have you done a coolant flush lately?

Over the recommended lifetime of coolant, the rust inhibitors reach lower and lower levels. If you've put off changing your coolant for too long, the radiator could start to rust. A coolant flush could loosen up a bunch of rusty threads from five years ago and cause everybody to shake their head under hard acceleration.

[Ron Burgundy]

In 2 WD hard accel---spark plugs, advance mechanism is sticking or sluggish. Or transmission 1st is by-passing into 2nd or even 3rd

First of all... What?

And secondly,

Have you done a coolant flush lately?

Over the recommended lifetime of coolant, the rust inhibitors reach lower and lower levels. If you've put off changing your coolant for too long, the radiator could start to rust. A coolant flush could loosen up a bunch of rusty threads from five years ago and cause everybody to shake their head under hard acceleration.

If this was intended for the OP, this thread is being brought back from the dead, he/she is probably long past this issue by now (at least I would hope so). If this was intended for ARKQX33V6, then kudos to you for being able to comprehend that...