Transmission oil cooler

When you need transmission cooler?

For some markets and engine alternatives, an oil cooler is factory-fitted.1

When towing a camper or when driving with similar heavy loads, the fluid temperature in the automatic transmission could rise to high values and cause overheating. Thus when a towbar is mounted on a car with automatic transmission, the fitting of an oil cooler is recommended (certain markets and engine alternatives only. See guide below).

Part. No.



Need for oil cooler

Part number




2.5T, 5-cyl gasoline







3.2 I6







Technical data


  1. See the vehicle specification.
  2. For extremely hot climate markets in combination with tow hitch.

The transmission cooler itself – Volvo #30792717
Short hose between cooler and radiator – 31212265
replacement transmission line – 30792185
Washer 986499
Spring Nut 949921
M6x14 Torx bolt 986213
2 quarts of ATF. I used Castrol Import Multi Vehicle, but any JWS3309 fluid will work obviously.
Funnel with about 2 feet of plastic tubing about 1/2″ diameter or so.


T30 socket
T40 socket
T55 socket
8mm socket
long extensions
13(?)mm socket


Official Volvo guideline

XC90 trasimistion oil cooler

Accessories page


1. Remove the 6 mounting bolts for the front scuff plate in the middle of the bumper. Once you remove these, you have to lift up on either end to clear the cross member it attaches to. Push it as far forward as possible. You will not be able to remove it from the car without removing the front bumper cap cladding, but this is unnecessary. Also remove the drip pan from underneath the car.

2. Wiggle the transmission cooler through the front of the bumper and lay it out of the way on top of the scuff plate.

3. Remove the two 8mm bolts holding the power steering cooler to the front of the A/C condenser core.

4. Sandwich the transmission cooler between the A/C condenser core and the power steering cooler and reinstall the two 8MM bolts, do not tighten completely.

5. Apply some ATF to the O-rings on the short hose and snap into the bottom outlet of the cooler.

6. Install a spring nut in the blank on the side of the radiator. This is the anchor point for the replacement transmission line.

7. Route the replacement transmission line between the cooler and the transmission. This replacement line will replace the lower transmission line on the TF80-SC transmission. Others may be different. I followed the routing of the original line that connects to the top outlet on the radiator. Once you have that routed, coat the o-rings on this line and snap into the upper outlet of the cooler. Use the M6x14 Torx head bolt (T30) to fasten down the transmission line to this.

8. Tighten down the mounting bolts to the cooler.

9. Coat the O-rings on the short hose on the free end to the radiator, and then unclip the top hose and then quickly snap in the short hose in its place. This will help minimize your mess.

10. Coat the o-ring on the transmission side of the new line with ATF, and then remove the 8mm bolt holding the line into the transmission. Use a drip pan underneath as fluid runs out pretty fast. Try to do this step quickly as you will lose a good bit of fluid from the transmission while swapping out the lines. Install new hose and tighten the bolt. Wiggle the old line out and set aside. You can save this line for whenever you decide to do a flush later.

11. Reinstall the scuff plate. I tightened the two frame bolts down to about 60 ft-lbs each since they seemed pretty tight coming out. The upper two bolts that thread into the scuff plate itself I did at ~30 ft-lbs.

12. Remove the air cleaner assembly. This is a little tricky, but I was able to leave everything connected to the engine and the module on top of the box and just flip it up out of the way as best you can. Remove the fill plug T55 and install the tubing connected to your funnel. I found a funnel with a tube on it that was perfect at Advance Auto Parts so I used that. Snug fit which is good so it doesn’t slide out. Put the air cleaner back mostly in place but not so much that it kinks your fill tube.

13. Start the car, and let it idle for a couple minutes. If you’re on ramps or jackstands, lower the car so that it is on mostly level ground. Then run through the gears from P to D and then back a couple times, stopping at each setting for about 2-4 seconds.

14. Position your drip pan underneath the drain plug on the transmission. This is the plug a screw in the middle of it.

15. Remove the drain plug’s level plug (T40). The drain “plug” is actually a tube that protrudes into the transmission case. As fluid is added to the transmission to the proper level, it will run or drip out of the hole.

16. You may see some oil drip out of this at first, but should not be very much. Slowly dump in the new ATF up top until you can see fluid run/drip out the plug in the bottom of the transmission.

17. Let the car idle for a while to warm up to operating temp. This will probably take on the order of 15-20 minutes. According to Volvo, the temp should be +50C to get an accurate level. I talked to a tech at the local Volvo shop that said you can measure this with an infrared temp probe on the solenoid cover on the front of the transmission (this is where the internal temp sensor is located). I didn’t have one of these so I reinstalled the plug in the top and bottom of the transmission and drove the car for about 5 miles round tip, and when I got back, while the car was running I removed the level plug in the bottom of the transmission and measured the temperature of the escaping fluid at around 50C with a candy thermometer.┬áReinstall when it quits dribbling.




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