Vs commodore 96 wagon ..is it a trans problem ??

[Eagleeye]

When i'm say, going up a hill, have a bit of weight in the car, or have my dog trailer on the back, going at between 80-95 klms p/hr , ask the car for a bit more effort I hear and feel a "grrrr" kinda noise, I can feel thru the pedal that if I try/give it anymore its going to get louder/worse, I ease off a touch and then get on the flat road have no probs easing it upto 100-110kph, but if I "go for it" between the 80-95kph speed I get that "noise" had the car for over 12 months, nice car no dramas as I "drove around the problem" but anyone got any ideas on exactly what might be the problem, if I had a punt myself (i have no idea about cars) but just being the driver and "feeling" the prob I'd guess that the tranny is slipping between 3rd and 4th gear, would that be right ??

any ideas appriceated,

Adam.

[shane271184]

hi i have had a couple of commodores do what it sounds like yours is and one was the center bearing in the tailshaft you would feel it shudder on hard acceleration or when towing and the other was just plugs and leads going up hill in this one and you would feel the diff was going to shake out flat and gentle driving would feel fine. hopefully its one of these and not your auto.