Changing transmission oil

Transmission oil change intervals

The owners and service manual recommends the following intervals:

• Normal driving conditions: Every 144.000km / 90.000miles or 6 years (which ever comes first)
• Harsh driving conditions: Every 48.000km / 30.000miles or 6 months (which ever comes first)

Definition of harsh driving conditions

The service manual states the following definition:

• Less than 8km (5 miles) per trip on non-freezing weather conditions.
• Less than 16km (10m miles) per trip on freezing temperatures.
• In hot weather climates with temperatures above 32°C/90°F.
• Extensive idling or long periods of stop-and-go driving (e.g. as taxi or commercial deliver vehicle).
• Driving on mountainous roads.
• On muddy, dusty, or de-iced roads.
  

Additionally definition from other S2000 owners:

• Sport and fast paced driving with a lot of VTEC engagement.
• Long periods of driving at 150km/h (93 mph) or above.
• Racetrack driving (most people recommend to change the oil after each racetrack visit).

Recommended transmission oil

See: Transmission oil recommendations

Required tools and fluids

• 1,6L/1,6qts transmission oil (or a little more if you would like to "flush" the transmission)
• New crush washer for the oil drain bolt (Honda #91409-14000 / 14/24/Aluminium / See: Washer#Transmission_oil_drain_bolt)
• New crush washer for the oil filling bolt (Honda #91409-20000 / 20/x/Aluminium / See: Washer#Transmission_oil_filling_bolt)
• 17mm socket
• Ratchet
• Torque wrench (40Nm / 29 lb-ft and 44Nm / 33 lb-ft)
• Oil catch pan
• Floor jack + 4 jack stands
• A lube pump since it is hard to fill the transmission without it

How to change the transmission oil

Pre-conditions and jacking up the car

• Before you start it might be a good idea to drive the car for a while to increase the temperature of the oil in the transmission.
• Put the car in the first gear and set the parking brake.
• Jack up the car on the front by using the central jacking point near the engine.
• There are two front-jacking-points on each side. Place one jack stand on each side at the jacking-point that is the furthest away from the front wheel.
• Lower and remove your floor jack and continue jacking up the rear by using the jacking point on the differential.
• Place your jack stands on the left and right side jacking points at the rear of the car.

Draining the oil

• The transmission is located behind the engine and has two bolts (drain and filling) on the drivers side.
• The lower bolt is the drain bolt while the upper one is the filling bolt.
• Place your oil catch pan below the transmission drain bolt.
• It is a good idea to first remove the filling bolt and afterwards the draining bolt. This ensures that the filling bolt is not stuck and prevents you from ending up with a drained transmission that you can't re-fill.
• First remove the transmission oil filling bolt with a 17mm socket from the transmission.
• Next remove the transmission oil drain bolt with a 17mm socket from the transmission.
• The old transmission oil will now drain from the transmission and you might need to re-adjust your oil catch pan.
• You will notice that once the filling bolt is completely gone, more oil will come out of the transmission oil drain.

• Once all the oil has be drained I like to fill fresh oil into the transmission to "rinse or flush" the transmission with the new oil.
• Wait until no oil (either old or new from "rinsing") comes out of the transmission.

Adding new transmission oil

• Replace the old crush washer from the transmission oil drain bolt.
• Usually the crush washer will have two sides, one that has a rounded edge and one that has a sharper edge. The sharp edge should face the transmission.
• Hand tighten the transmission oil drain bolt. Then use your 17mm socket and a torque wrench and tighten it to 40Nm / 29 lb-ft.
• Fill in the transmission oil through the filling hole until the new transmission oil starts to leak out of the filling hole.
• This is the indicator that there is enough transmission oil in the transmission (usually 1,6L / 1,6qts).
• Replace the old crush washer from the transmission oil filling bolt.
• Usually the crush washer will have to sides, one that has a rounded edge and one that has a sharper edge. The sharp edge should face the transmission.
• Hand tighten the transmission oil filling bolt. Then use your 17mm socket and a torque wrench and tighten it to 44Nm / 33 lb-ft.

How to make sure no old transmission oil is left in the transmission

This guarantees almost 100% that no old transmission oil is left in your transmission and that it has been exchanged completely with new oil.
The same procedure is used by oil companies between test cycles in their R&D facilities.
You might want to do this when changing to a different type or brand of oil.

• Repeat the steps How to change the transmission oil three times and drive your car for a short time between each changing cycle.