ok i have question -> is this normal? i have a 2003 auto cls btw...
i live on a hill, so i was backing out of my driveway the other day, and this is what i did.

1) backed up the hill in reverse.
2) shifted to Neutral
3) let the car roll down the hill in N for about 10-20 ft. (no gas)
4) shifted into D while still rolling (still no gas yet)

*GRIND* ...

my car made a quick grinding sound and then everything was normal... I did it again the next day, and after that, i decided not to do that anymore

 

ouch!@!!!!!!!! don't EVER Neutral drop it into gear!!!!!! BAD BAD BAD!!!!!!!!!!!! always come to complete stop with you foot on the brake then shift into gear.

 

Yup.. that's a standard Acura noise... it's morel ike a clunk then a grind...right? That happened on my '98 CL as well as my TL and it only seems to happen when on a hill and rolling before putting it in D4 or D5. Obviously the best thing to do is not shift like that

 

it wasnt really like a clunk.... i made the clunk noise in other cars, but that was neutral dropping from standstill... this is neutral dropping from moving... and it was a sort of high pitched grind... not the normal grind you make when, for example you shift into reverse in a manual when you're still moving... it was much higher than that...

 

I second what Zapata commented on, I wouldn't ever allow the car to roll 'on purpose' in neutral before shifting into gear (or from reverse into a drive gear) unless the car has stopped rolling significantly. Even without providing any amount of gas, i'm thinking you could cause some serious damage to a somewhat weak transmission already.