Slippery Transmission

Recently did Transmission rebuild soon after noticed that it’s slippery. When I start the car in the morning it’s not rolling as it should. I let it worm little like 3minutes then start driving but still it’s slippery when it comes to a very little hill not taking the gear.
After driving on the straight road for 4-5 blocks then its fine no problem at all. Only when car gets cold this issue happen.

So I’m gonna go ahead and ask the obvious here. Full of fluid ? Correct fluid ? What year ?

I assume that by “slippery” you mean that it is slipping - as in, you it the gas and engine revs up but the power doesn’t really transfer to the wheels.

How is the fluid level?
Who rebuilt it?
Do you have any warning lights on the dash?
What year is this Town Car?

Cig’s questions suggest that he reads minds… he just read mine!

You need to answer the questions for us to help you. If your fluid is low, or the wrong fluid, the torque converter may not be properly transferring the torque to the tranny. If you had a shop do the rebuild, they should be addressing the problem. If you did it, we’ll need to have you double check some things.