grand prix transmission problems

[brentwilliamsm]

So my Grand prix has been acting up a lot lately. it shifts hard into second sometimes and sometimes it wont even shift to second untill about 3500 rpm. and about 4 times a week, ill be going a steady 35 and the rpms will shoot up to 3000 for about 4 seconds then itll go back down. does anybody know what this is, why its doing it and roughly how much it will cost to be fixed? greatly appreciate any help given.

[Rico]

Make sure you do some general maintenance before jumping to any conclusions.

What transmission do you have 4T60E, 4T65E or 4T65E-HD?

[BillBoost37]

Or if you don't know your trans...which year model and motor do you have?

[brentwilliamsm]

It's a 98 3.8 3800 series

[brentwilliamsm]

And yeah, about the general maintenance. I planned on getting a transmission flush today. Replacing it with synthetic. Well see how that does

[brentwilliamsm]

Oh and its a Gt

[BillBoost37]

4t65e.