The T-Series gearbox has bronze synchro components. Use an API GL-4 oil — modern GL-5 hypoid oils contain sulphur-phosphorus additives that attack yellow metals.
Step by step
- 01
Warm the car and get it level
Drive briefly to warm the oil, then chock the wheels and raise the car on axle stands so it sits level front-to-back and side-to-side — level matters for a correct fill.
- 02
Find the filler/level plug first
Identify the filler/level plug on the side of the gearbox before you undo anything else. Golden rule: if you can't get the filler out, don't drain — you'll be stuck with an empty gearbox.
- 03
Drain the old oil
Place the drain pan under the gearbox drain plug. Slacken and remove it and let the oil drain fully. Inspect the plug (a magnetic plug traps swarf) and clean it before refitting with a sound washer.
- 04
Refill through the level plug
Refit the drain plug. Fill through the filler/level plug with the correct grade until oil just weeps from the level hole — that is the correct level. Refit the plug with its washer.
- 05
Road test and re-check
Drive briefly, let the car settle level again, and re-check the level and for leaks around both plugs.
Read next
This guide is a general introduction and is not a substitute for the official Workshop Manual for your car.