Quote Originally Posted by ReggieMar View Post
Even if I go higher than 80kph and stuck in 5th gear the jerking still occurs. This could be a serious problem? should I go the a mechanic right away?
Well, I wouldn't just trust any mechanic. For my transmission problem with the Toyota '97 Revo Diesel (manual) as well as '07 L300 FB (manual), I brought it over to Payless Car Care Center in Quezon Avenue. I trust the lead mechanic there named Mar and he was very helpful for all my concerns with the cars.

He had also fixed the suspension of Honda City '08 i-DSI 1.3CVT and done change oil for it. But if he isn't there, I tend to be wary of the other mechanics.

This is what I would suggest. But best is to bring it to Toyota to have them do a full check to be sure since I am suspecting it is a transmission issue, not an engine issue (Disregarding what Petron did with the engine oil viscosity but do have that checked as well).