ATF (Automatic Transmission Fluid) Change - 850 - Howto

[TenaciousC]

Hi,

Thought I would write this as IMHO the Haynes manual over-complicates the job by requiring the removing of the battery tray and the need for tubes and bungs and all sorts of intimidating paraphernalia . It is an important job we should probably do more often especially with uprated BHP.

Pre Requisites

• 24 mm socket (transmission drain plug)
• 21mm (13/16th) Open Spanner (transmission oil cooler fluid return union)
• 10mm socket (splash guard)
• 10 litres of Dexron III ATF (Automatic Transmission Fluid)
• An old washing up bowl or other suitable draining receptacle
• A small funnel that fits into the ATF dipstick tube
• A large funnel for pouring spent fluid into a holding container for disposal
• Latex gloves
• An assistant to start/stop engine

Procedure

1. Warm up car on a short drive
2. Jack up front of car and support on wheel stands.
3. Remove splash guard (2x10 mm bolts either side)
4. Position bowl under transmission and remove 24mm drain plug. Be careful as your fluid may be quite hot. Also watch out for the metal sealing washer. I found mine in the bottom of the bowl.
5. Allow fluid to drain. Whilst you wait you can loosen the oil cooler return hose. This is the flexible hose that goes from the bottom of oil cooler (which is built into the radiator) to the top of the transmission (just under the battery tray). Loosen the union on the top of transmission with the 21mm spanner. Access is limited but by no means difficult.
6. When fluid has finished draining, replace the 24mm drain plug (and washer) and tighten
7. Decant the old fluid into another container using your large funnel ready for disposal.
8. Move your empty fluid catching bowl to the vicinity under the oil cooler return hose. Fully undo the oil cooler return hose union thus disconnecting the hose. You will find this hose very flexible and able to rotate at the union of the oil cooler. This will enable you to aim the hose directly into your bowl.
9. Using your small funnel add 2 litres of new ATF to the transmission via the dipstick tube. Replace dipstick.
10. Get your assistant in position in the driver's seat. With one hand, aim the free return hose end at the bowl, and using a finger on your other hand, plug the open hole of the union on the transmission.
11. Have the assistant check the gear selector is in Park, and start the engine. Fluid will now come shooting out of the hose into the bowl. Watch carefully, it will start to turn redder, and eventually air will cause the stream to splutter. At this point have your assistant shut down the engine.
12. Repeat the process (steps 9,10,11) once more.
13. Dismiss your assistant, and get them to make tea.
14. Reconnect the oil cooler return hose to the transmission and tighten.
15. Re fit the splash guard.
16. Remove axle stands and lower car to ground.
17. Add 2 further litres of ATF to dipstick tube
18. Start engine. With foot on foot brake, move selector through each position pausing for 5 seconds in each position.
19. Leave engine running and wait 2 minutes.
20. Whilst engine is idling use dipstick to check fluid level, (against COLD) side of dipstick.
21. Top up carefully as required adding 500ml of fluid each time. Use same process to check fluid level (steps 18,19,20). Remember that too much fluid can cause more problems in the transmission than too little. The difference between Min/Max marks on the dipstick is about 500ml.
22. Dispose of spent fluid appropriately.