Transmission backlash?

[stocker2000]

Hi,

My 2000 Altima w/ about 60,000 miles on it has developed what I think could be termed backlash. When I let off the throttle, the car jerks/rocks rather violently. This is accompad by a "clunk-clunk" sound. It's most noticeable when doing about 30 mph in 3rd gear. It's as though the vehicle cuts the gas to the engine too abruptly. Having driven other manual transmission vehicles (although never another Altima), I have never noticed this extreme a jerk when releasing the throttle.

Come, the think of it, the throttle seems pretty abrupt in general, whether letting off of applying.

I'm wondering if something is out of adjustment, such as the throttle cable, or if perhaps the TPS may need cleaning/replacing. Maybe it's something else entirely. I doubt it's the engine/transmission mounts as they were all replaced earlier this year under warranty.

Any ideas for fixing this abrupt throttle? Or is it simply a characteristic of the vehicle design?

Thanks in advance.

[s13sr20chris]

i strongly recomend ruling out the mounts first. try to get the vehicle on a lift and watch from underneath to see if the mounts are good. actually you good just have it one the ground and watch to see if the powertrain is moving too much while someone brake torques the engine with the clutch slipping a little.

[stocker2000]

The mounts were replaced earlier this year, but I checked them again.

I got a pry bar, and wiggled to see how much play I had. I had someone blip the throttle too, and didn't see any undue movement. I didn't do a brake torque test as I've never done it, and neither had the person helping me. I really think the mounts are OK.

ONe other point of note, it does get slightly better once the engine warms up. Any other suggestions.

[s13sr20chris]

well, the clunk clunk should be the focus right now. i think if you find the clunk clunk you will find the whole prob. just a thought. for that i would reccomend going over the suspension/brakes with a fine toothe comb. jack up and shake the snot out of the wheels in the vertical and horizontal directions. by this i mean push on one side and pull on the other. check for loose bolts on control arms, calipers, caliper torque members, crossmember, etc. i would have a look at the shift linkage and bushings in the shift linkage too.