My rearend in my 01 gt has lots of play in it.

When i remove the driveshaft i can turn the rear almost 2 inches back and forth.

What would cause this?

When i press the gas and let off at low rpms it clanks in the rear also.

 

So you saying that the entire rear axle moves 2" fore and aft OR side to side? 2" does seem excessive.

Fore and aft movement could be severely worn control arm bushings. There is also a large pinion snubber that is meant to control axle 'twist' (wrap up).

Side to side movement is control mainly by the panhard bar. It also has bushings that can wear out.

 

I meant to say the pinion turns 2 inches back and forth before it turns the wheels.

 

That is known as backlash- a clearance between the pinion gear and ring gear. I don't know the spec. off hand, but some play is normal.

 

I checked some other vehicles of mine and they have like only 1/2 inch of play.

 

Yes, 2" does seem excessive.

 

could it be the spider gears???

 

Try this: apply the emergency brake with the vehicle on the ground and in neutral (on level ground). Try to move the driveshaft by hand in either direction again. The emergency brake will prevent the axle shafts and spider gears from moving. If there's still excessive play- then the ring and pinion are your culprits.

 

Yes it still does the same thing.

 

Well, I think that we've figured it out then- excessive backlash. This can be adjusted using shims, but depending on the mileage- a differential rebuild or gear set replacement may be needed soon.