Coasting to a Stop: front end "catches"
 

I notice a sort-of "catching" or slight mechanical resistance felt when letting off the accelerator at low speeds (like when approaching a stop light and you take your foot off the gas pedal for example, or when manuevering in a parking lot or other low-speed environment). Sometimes the car will coast normally, others I will feel a slight catch or mechnical feel from the front--nothing violent but it is noticeable. I've heard it may be a little slack in the differential chain up front. Does anyone have any suggestions? It doesn't seem like a major problem, I just don't want it to get progressively worse. 02 ML320 w/ about 82,000 miles.

I do not hear any audible clunking or clicking sounds. It's hard to replicate on demand so I want to approach the serv techs with some idea.

Thanks so much!

Travis