VN auto gearbox changing gears by itself

[peterthomas70]

Hi to everyone here, now can any one help me with this problem i have?
I own a 1989 VN commodore with an auto when driving in Blue D (overdrive) at around 100km's an hour it will change down from 4th to 3rd, and then back up and down, sometimes continuously over and over again.
It doesnt happen everyday but the problem seems to be getting worse, it goes through all gears very smoothly but once you reach around 100kmh on a highway etc thats when it occurs.
Have now noticed When you go over a bump in the road thats when it changes back to 3rd, Seems to me like something is loose maybe....??????????.......
Transmission fluid is full as well.
Please can anyone help me as i dont have a lot of money being a disabled pensioner but i can get a mate to do the work or take to a gearbox specialist but not get ripped off by knowing what might be the problem.
Regards
Peter......

[Haydz]

i LOLD i read the title and thought. its automatic. so it should shift by itself.

[jas98]

i LOLD i read the title and thought. its automatic. so it should shift by itself.

haha same

as for the problem check the fluid level as this was the sameas what me mates vs had....but if the level is good (might pay to change oil and filtre) then id say the box is on its way out

[Morton]

Could be a kickdown issue. It may be sitting too tight.

[Fatvl308]

first check the fluid levels otherwise the trannys ****ed get a reco