This is a 2000 ML 55 with 84k miles. I picked up the car from valet parking and the transmission was rattling like crazy, not engine or transfer case noise. It shifts and drives normally no problems there. Could the valet have put it in park prior to stopping causing the noise and rattle, especially at idle? Could the linkage be out of adjustment? I removed the inspection covers from the transmission bell housing and no loose parts fell out! What about lack of transmission fluid? There are no leaks. I am in Las Vegas, would the heat have caused part of the problem? Thanks for your help.

 

Is the rattle present idling even with shifter in neutral and park position? Operating temperature of your transmission is alot higher then ambient, it should have no effect.

 

someone had some fun with your truck! i never use valet. ever.

 

I'm thinking the same way. Some kid was having too much fun on dry pavement with it.
I had simular problem in 1997 on my '80 280SE, flex plate between flywheel and torque converter was cracked, holding on with one good screw connection, all other still there but cracked off. I'm sure it was my driving style that did it, I was still young, dumb and lucky because my uncle owned auto repair shop and half was rented to Multistate Transmission so I got free professional help with tranny checkup.