Dear all,

I'm driving a 2001 Volvo S80 T6 Executive, 118k miles and 4T65EV-GT transmission

1.
I'm having problems with my transmission made by GM (thx alot..not). When it shifts down it knocks a little bit and sometime when shifting up as well. Few weeks ago on hard acceleration it knocked really hard. And once or twice the car vibrated when shifting on hard acceleration.
Is it possible that changing the oil and filter might fix this problem with the knocking? I don't know when it was done last time. If not, what could possibly be the fault?
The vibration gives me a bad feeling, like the transmission is slipping.
Or any other recommendations?

2.
The lock for both front and rear drivers side doors are acting funny. They sometimes locks and the pops up right away when locking the car. Could it be the anti-theft module (siren) ?

Any free advice would be greatly appreciated since I've just recently spent a lot of money rebuilding both turbos and changing piston rings because of an ignorant worker at the dealers workshop!

BRGDS
A Kristjansson