A Bit Confused

[03GrandPrixGTAZ]

I drive a 2003 Grand Prix GT, with about 188k miles. I bought it with 185k on it about 2 months ago, as I am fond of buying older cars that aren't seen around as much, and I grew up with my aunt always driving Pontiacs. I have since replaced the emission purge valve, and plan on restoring 'Laurel' to her former glory. She needs struts/shocks, but that isn't contributing to the issue at hand.

The past couple of days, when I placed my car into the reverse gear, I heard a fairly loud clunking sound while it was in gear (sort of like a rock tumbling around). I heard it again today when I was backing out of my driveway, as well as when I pulled over about 100 yards up the road and put it in reverse to see if it was still there. I brought the car to my guy to see if he could tell me what was wrong, but once the car warms up, it will no longer make the sound. I'm at a loss as to what it could be. The car drives fine (driven over 150 miles the past 2 days), and I don't hear the sound in any other gear. The tranny fluid is fine, as well.

Any insight as to what could be causing this would be great. I don't know if anybody else has ever had this happen. Sidenote, I am unclear as to whether the transmission has ever been replaced before. Any help is appreciated.

[rickisrad]

Well I would say check all engine/trans mounts and the cv axles. My axles clunked when put into reverse with aftermarket ones. Since it goes away with warm up it may not be those things or just coincidence. You say the fluid is fine, have you changed the fluid and filter??

[03GrandPrixGTAZ]

Yes, they were just changed when I bought the car. I did notice a groaning/grinding noise when I was turning left this morning, so the CV axles very well could be the problem. I will get that checked out and see if that's the issue. The top motor mounts are fine, I replaced those when I replaced the radiator as well, the day after I bought the car.

[rickisrad]

how about the bottom mounts??

[03GrandPrixGTAZ]

how about the bottom mounts??

Haven't been able to check those yet, as it happened when I was on my way to work this morning. I'm going to have the mounts (both motor and trans) checked tomorrow, and see if that could be the problem. I just wonder why it would only do it when it's cold, and only in reverse.