1999 chevy tahoe will not go in any gear when warm when i stop & restart...

[Tahoe 99]

...engine goes in gear and stops again? and when it it doesn't go in to gear a hear a rattle noise

[Rudedude]

On some trany in that year a C Clip breaks off in the trany letting the output shaft move slightly causing a no go with a rattle come grinding noise. Like the other post says first thing to check is the fluid level and condition. If low top it up if its dark brown to black or has metal in it you could be in for a big bill.

[Mr. KnowItAll]

Hows the tranny fluid level?

Check it in "Park" and engine running.