I have a 2002 Blazer ls 4x4 and in the morning when I start it up and put it into drive it shifts really hard. It has plenty of fluid in it . But after it warms up it's just fine. What could this be?

 

The solenoid shift sensors.


Its old and needs TLC until up to operating temp.


You might do new tranny filter and tranny oil to help it along some. Its going to resolve issue. But may prolong its life.
But the shift sensors / solenoids are old and not working as well.

Another often over looked item.

As a engine is old. High milage lower compression. When the vehicle is cold. The low compression means the tranny must over work. Due to the engine being week on power. As the engine warms up. The compression comes up too.


If you have ever read or know . that all compression tests should be done with the vehicle warmed up. To get accurate reading.


The odd ball of low compression. Is that when cold the compression can read high and once warmed up. It drops allot.

How and why ? Mostly as bearings go bad or the crank bearings. Naturally stiff and tight in cooler weather.


Take read in the middle of the road point of view.

Hope this helps.

 

So ur suggesting to change the filter the fluid and the shift solenoid and that should help or fix it