VS auto gearbox problems

[periperi]

Hi I have a 95 vs comodore , I had the auto trans done about 20 000 km ago , It runs all good but as soon as the gearbox gets warm it wont change into 4th , Yo can drive from cold and go no problem for a long time untill you slow down and ounce it changes done to 3rd it refuses to change back up , Please help anyone ,

[tt460]

checked the fluid level and codes ?

[hako]

As above - check for codes. Sounds like your car is going into Limp Home Mode which should log a code...possibly a solenoid sticking. Follow these instructions: Checking error codes VR/VS (Revised)
And welcome to the forum.

[rocco555]

take it back to where you had the work done... problems after just 20k is not acceptable

they should fix it for free (if still under warranty) or for a small sum if not