PREFACE: Searched about and couldn't find a DIY on the IS350 Differential fluid change. I did find a nice one for the IS300. It worked very well as a reference, so I completed the below IS350 DIY with high credit to the IS300 article author: My.IS forum member Hiroshima - LINK. Imitation (plagiarism) is the sincerest form of flattery. I hope DIY'ers here find it helpful.
DISCLAIMER: The procedures, methods and products written up here were performed my 2007 IS350 with HKS exhaust (may make for some clearance difference if you have a stock exhaust). I make no promises that your results will be the same nor do I claim that this is the best way to do it. USE AT YOUR OWN RISK! I assume no liability if you crush your fool self or set your car on fire and burn down your house (or any other series of unfortunate events).
WARNING: Automotive fluids are not good for you. Like the author of the IS300 DIY, I have no reason do doubt the statement that used fluids are carcinogenic. Use latex/nitrile gloves when handling used automotive fluid, and wash your hands ASAP after you have completed the task.
WARNING: When working under a raised vehicle do not depend on the jack alone!!! Use jack stands and place them under the lift points as described in the owner’s manual.
Time Required: 45 Min (more or less, depending on your experience)
Differential Drain/Fill Crush Washer Part Number: 12157-10010. (Buy at your Toyota dealer or online...Lexus dealers seem to think these are made of gold...) (QTY to Purchase: 2 - for fill and drain bolts)
-Toyota Synthetic Diff fluid (if you can mystically find some)
- Amsoil SVG 75W90 or so I am told.
- Mobil1 LS 75W90
- Pick a winner of your own. Manual calls for (synthetic) 80W90.
- Breaker bar
- 4" socket extension
- 10mm allen key 3/8” socket
- Torque wrench capable of up to 40 ft lbs
- Fluid pump (pictured later) or a spill stop fluid tube
(Use 1/2" tools if you have those. Makes no difference, except perhaps a bit of clearance)
If your vehicle is cold, drive a bit to warm up the differential fluid. If the car is already hot, skip this step. Warm diff fluid will drain faster and more completely. Be aware that you are also working very close to the exhaust piping. Keep in mind that your diff fluid will be HOT (or at least quite warm). Take appropriate precautions.
Step 1: Jack up the car. The car should be ‘level’ when jacked up. If you have four point jack stands, use those as it will be much easier to maneuver under the car. My garage backs up to the nice fairly quick slant of my driveway so just a bit of jacking on the DRIVERS side (diff fluid drains toward the passenger side), and I can keep the car level (again, use jackstands where appropriate)
Reference: Pictured below you will see the differential housing. This is the passenger-side view. The bolt on the top-right is the FILL bolt, the bolt on the bottom-left is the DRAIN bolt.
Step 2: Remove the *FILL* plug first. If you for some reason you drain the diff and cannot get the fill plug removed, you will have to flat bed your car to the dealer. Better to be safe and make sure you can undo the fill plug first. Use the 10mm allen head socket and the breaker bar. This bolt will be tight. Make double sure that the allen head is square and firmly in the hole before applying force.
Note: I had to use a 4”socket extension due to the position of the exhaust. Not sure if there will be any additional clearance with the stock exhaust.
Step 3: After you remove the fill plug, remove the drain plug using the same 10mm allen socket and the breaker bar. You have just enough clearance to sneak in there. Have your drain pan ready. To keep fluid from splashing on the exhaust, I use a funnel to route the fluid until it slows enough to not be an issue. Not required, I just don’t like a mess.
Step 4: Allow fluid to drain. Get a drink, watch a show on TiVO, whatever. Just give it time to drain. Even warm diff fluid is fairly thick.
Note on amount drained: I wanted to know how much fluid was ‘actually’ drained from the differential. After the differential was drained, I emptied my catch pan into an empty container with level markings (see below). Looks like right at 1.5qts was drained, so pretty close the 1.42QTs in the manual, given that some fluid is bound to still be in the diff housing.
Step 5: Clean the drain plug. The plug is magnetic and is designed to capture and hold the fine metal shavings associated with normal wear. The plug should have a black coating of goo and metal particles. If you see large metal shavings or chunks, see your dealer.
Step 6: Replace the crush washer on both the drain and fill plugs. Reinstall the drain plug and torque to 36 ft lbs.
Step 7: Remove the entire cap from your new diff fluid. Insert your fluid pump. Place the dispenser end into the ‘fill’ hole on the differential. (You can alternately use a ‘spill stop’ tube and get the bottle as high as you can under the car…the fluid pump is just a heck of a lot easier)
Step 8: Positioning the diff fluid container (with attached pump) just right of a brace there is enough room for it to fit standing up. Pump away; you’ll empty the first container and need to use about half of the second container. Transfer any left over fluid from bottle number 1 to bottle number two. The fill spec for the IS350 differential per the manual is 1.42QTs. Using the “fill until spill” method I put in right at 1.5QTs. (“Fill until spill” – continue to fill until fluid begins to run back out of the fill hole in the differential)
Note: The fluid pump displaces some of the fluid in the bottle and will give you an artificially 'high' reading on how much fluid is left in the bottle. You will have to slide it out part way to get an actual check on how much you have pumped into the differential, if you choose to use 'accurate measurement' over 'fill until spill'.
Step 9: Wipe off any spillage near the diff fill hole. Replace the fill plug (remember to use a new crush washer). Using a 4” socket extension, torque to 36 ft lbs.
Step 10: Double check the torque on your fill and drain bolts. Done. Clean up, recyle your used oil, get a drink.
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I was scheduled to do mine today, but a different project took more priority...
In post one you should note that 2 washers should be purchased for the drain & fill plugs..
Curious, how much did one bottle run you?? I paid $15.99 today at Autozone.. I think a few years back they were under $10..
Also, I see how your plug looked at 18k miles.. What was the condition of the gear oil??
Mine is just over 25k miles, I expect it to maybe be a bit worse..
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In post one you should note that 2 washers should be purchased for the drain & fill plugs..(Done!)
Curious, how much did one bottle run you?? I paid $15.99 today at Autozone.. I think a few years back they were under $10.. $14.98 per bottle at Pepboys. A bit steeper than my last purchase as well. I think it was $12.99 last time.
Also, I see how your plug looked at 18k miles.. What was the condition of the gear oil?? Dark, but no soluble sludge came out, nor any metallic remnants other than the fine particles and sludge on the magnet. I didn't think about capturing a sample for UOA until after I'd dumped the fluid into my rycle tub. Too bad, I would have liked to see how it was standing up. I don't suspect there was anything terribly wrong, however. I've def seen worse come out of my jeeps! I was, however, quite surprised by the amount of gunk that was on the plug. That's why I left the dirty wipe cloth in that 2nd pic. That was a lot of stuff on there.
Originally Posted by Gernby
What made you decide to change your diff fluid? How many miles did you have on it?
~18K Miles. Just wanted to clean out any particles and junk and put in some high quality synthetic as a replacement.
To whoever says differential fluid doesnt need to be changed explain the gunk in the drain plug PLEASE ?
The color of the oil is insignificant, and the "junk" on the drain plug is just the metal shavings from the ring and pinion wearing in. The fact that the shavings are on the drain plug means that they are NOT in the oil, so they aren't a factor either. I don't think there is any need to change the diff fluid on a street car any earlier than the manufacturer suggests.
EDIT: I would bet that a UOA would show that the oil you changed probably still had plenty of service life left.