Sometimes when my Blazer is cold it will not take off when the shifter is in OD or D. It will take off in 1st or 2nd and then shift properly all the way through. Once it gets warm it operates just fine from OD. Any idea what this is? 120k on the odo so am I looking at a new trans sometimes soon?

 

What does the tranny oil look and smell like?
When was the tranny oil changed last.

 

The tranny oil suddenly turned very dark and had metal pieces in it about 20k ago. My mechanic along with an automatic transmission shop advised to stay away from changing the fluid because chances were the dirty fluid was what was keeping the plates shifting. lol
Looks like I need to save up some money for a tranny.