How would you know if you have the correct trans oil???

hi Andrew
I would suggest that the gear box has not been serviced this is why it is not changing gears as it should. If the oil is a bright Red then the oil might have been changed recently possible as the oil may have been burnt and it takes on a dark colour. have a look in the service and see if it has been stamped or see when the scheduled service for the auto should be if you have no service book i would be sus about it
Terry

Hiya Andrew

I'd drop the lot (engine also) and start new,thats what i did with my Hilux,Did not care if had been done 2k before...Now i dont need to guess or worry...

Cheers

could also be an aadjustment on the kick down cable, which is part of the sevice, for peace of mind change all the oils throughout the vehicle. Col

Andrew,

i also would drop the lot including diffs. use the toyota type IV trans fluid,same price as dexronIII but you dont need to flush the existing type out,use an aftermarket filter and gasket( approx $40 from trans place) dont use toyota filters and gaskets unless you have won powerball!! $36 for gasket, $127 for filter, hows that for ripping people off! the aftermarket one looks identical to the toyo one but 1/5 of the price. if it persists in not shifting down maybe chat to toyota as most auto places have never seen a 5 speed in one of these things.i run peak global diesel oil in the engine, use sakura filters(good paper weight in it and cheap for 5K changes) i also use their GL5 limo oil in the diffs as have both ends with air lockers. also use genuine hoses and belts as they fit perfectly and are not expensive, comparable to non gen. hope this helps cheers Paul