How to drain and fill the sealed 4th gen 4runner Automatic Transmission
After tons of digging, there isn't really any clear information on how to drain and fill the transmission, and the info that is out there is so scattered, so I'll consolidate that information here.
The method I took was using the OBD2 port and jumping pins 4 and 13 to throw the car in diag mode.
This thread has solid pics on the first post, of the specific pins to jump:
How to Drain/Refill Automatic Transmission | Tacoma World
Tools:
- 24mm socket for fill port
- 14mm socket for drain port
- 5mm allen key for overflow port
- Toyota WS fluid of YOUR CHOICE
- fluid pump
- paper clip or wire with the ends stripped
Steps to drain:
1. Crack open your fill port first! If you drain first and can't open your fill port, your SOL.
2. Open the overflow drain port
3. Drain your ATF fluid. It's said that the pan holds around 3qts. Mine came closer to 3.5qts.
4. Once drained, tighten back the drain port (leave the fill port and overflow port open)
Steps to Pump fluid back in the transmission:
5. Pump Toyota WS fluid back into the transmission until some fluid starts to come out of the overflow port
6. loosely tighten the bolt back in the overflow port
7. Add about an extra 0.5 qt of fluid after putting the over flow bolt back in.
Now checking your AT fluid level:
8. With the car off, in park, jump your obd2 with pins 4 and 13
9. Turn on the engine
10. Cycle from P -> R -> N -> D -> N -> R -> P a few times just to cycle the fluid
11. Shut off the vehicle when you've shifted back into park and cycled a few times
12. Turn on the engine
13. Shift from P -> N (now we start trying to trigger the transmission diagnosis mode)
14. Shift from N -> D -> N about 6+ times (It should be 6, but I didn't count), until the AT Temp oil light turns on solid. At this point, the AT Temp oil light SHOULD turn off about 2 seconds later.
15. Once the AT Temp oil light turns off, shift into park.
16. If the steps were done correctly, when you shift into park, the AT Temp oil light should turn on solid for about 2 seconds and turn off. Now is the waiting game.
Once the AT Temp light turns ON:
17. Jump under your rig and crack open the overflow port
If fluid is draining out of the overflow port, let it drain until it trickles. Once it is trickling, put the overflow bolt back in and you've correctly set your AT fluid level. You're Done!
If fluid
is NOT draining out the overflow port, shut off the vehicle and add more fluid
Meanings of AT Temp oil Indication light AFTER SUCCESSFULLY getting into the transmission diagnosis mode:
Light Off: The AT temp is too cold, let it warm up longer. Mine took about 8 minutes to warm up. I've read some people's have taken up to 15minutes.
Light On: The AT temp is in the correct range to check its level
Light flashing: The AT temp is too hot. Turn off truck and try again later.
Lessons Learned:
- If the AT Temp oil Light remains on and doesn't turn off after 2 seconds, it could mean your AT fluid is already too warm to check. Let your truck sit to let the AT fluid cool down and try again after a few hours
- You have roughly an 8 minute window check the fluid range (I tested this by letting my fill port stay open until it started flashing), plenty of time to check it
