Eureka! '03 auto 4x4 cluncking prob. solved!

[x-ing]

I posted a thread in the 911 forum about my Auto 4x4 clunking and jerking.

The dealer said the tires wren't all the same circunference.
They put on new tires, didn't fix it.

Kept on putting on new tires untill all 4 tires were within 1/4 inch in circumf. of each other. Fixed The Problem!

Thank you for your input.

 

[410Fortune]

How does changing the size of the tires get rid of a clunk?
please enlighten us

 

[x-ing]

On X's with AWD or Auto 4x4, All four tires have to have the same circumference within 1/4 inch of each other so that the GEM computer will "see" that the front wheels and the rear wheels are traveling at the same speed.
Since the rear wheels were off by about an inch, this caused the tires to spin faster than the front, therefore, making the GEM "think" that the rear wheels were slipping, thusly causing the auto 4x4 to constantly engage with a different overall output ratio in the front from the rear causing transfer case binding -- hence, clunking and jerking.

 

[410Fortune]

Thank you kind sir! who put different size tires on it?

I bet you will be very aware of your tire pressures and wear

 

[x-ing]

I bought it used.

Tires were all marked the same size.
Guess it was the tire manufacturer's bad tolerance on the size.

At least I got 4 new tires for free!

 

[AspenX]

Cant beat a deal like that.