Differential Fluid change?
Thread Starter
Driver
Joined: Dec 2023
Posts: 65
Likes: 6
From: nv
Differential Fluid change?
Anyone ever change this fluid. I was hearing this wear grumbling sound when I would pull out of a parking spot and turn slow; it sounded like I had a flat tire but it didn’t do it all the time. Anyway , I took it to Costco to get all 4 tires checked to see if I had a defect. Tech said the tires are good but when he moves the back tires forward with his hands, he can hear the grumbling coming from the differential. He said it could be low. Anyone have this issue.
owner’s manual doesn’t mention changing this fluid unless it’s driven under the extreme conditions.maybe 23 years old is itself a extreme condition even if you don’t tow or drive nuts
owner’s manual doesn’t mention changing this fluid unless it’s driven under the extreme conditions.maybe 23 years old is itself a extreme condition even if you don’t tow or drive nuts
Last edited by 430sc03; Mar 6, 2025 at 11:19 PM.
Instructor
Joined: Jul 2007
Posts: 898
Likes: 195
From: NJ
I've done this rear diff fluid change twice in the lifetime of my car - now at 114k miles. So perhaps once every 50k miles. It is easy to do with the appropriate tools - just need a hex bit of the correct size - could be a 10mm but best to check and verify. Remember to loosen the fill bolt first before you remove the drain bolt. I used 75W 90 full synthetic - might have been Mobil 1 the first time but the second time was Valvoline in the convenient pouch container. Highly recommended service. I do not believe this lifetime fluid nonsense that the OEMs talk about. Just because I was relatively frequent about this rear diff fluid change for the SC, I did not experience any change in how the car performed but for two other cars I own where the rear diff fluid change was done at 60k and 75k miles respectively, there was a noticeable improvement in smoothness. It's an easy job so should not cost too much even if you have a mechanic do it for you. My guess is a qualified mechanic only needs 30 mins or less to get this done. Easier than an oil change cos there is less fluid to drain and no filter to worry about.
Thread Starter
Driver
Joined: Dec 2023
Posts: 65
Likes: 6
From: nv
I've done this rear diff fluid change twice in the lifetime of my car - now at 114k miles. So perhaps once every 50k miles. It is easy to do with the appropriate tools - just need a hex bit of the correct size - could be a 10mm but best to check and verify. Remember to loosen the fill bolt first before you remove the drain bolt. I used 75W 90 full synthetic - might have been Mobil 1 the first time but the second time was Valvoline in the convenient pouch container. Highly recommended service. I do not believe this lifetime fluid nonsense that the OEMs talk about. Just because I was relatively frequent about this rear diff fluid change for the SC, I did not experience any change in how the car performed but for two other cars I own where the rear diff fluid change was done at 60k and 75k miles respectively, there was a noticeable improvement in smoothness. It's an easy job so should not cost too much even if you have a mechanic do it for you. My guess is a qualified mechanic only needs 30 mins or less to get this done. Easier than an oil change cos there is less fluid to drain and no filter to worry about.
the thing about my car is it’s 23 years old. That means everything that hasn’t been changed are 23 years old. Fluids ,spark plugs … I wish I would’ve known to change this fluid. Like you said it’s cheap. Transmission fluid doesn’t need to be changed, but now I’m worried
Last edited by 430sc03; Mar 7, 2025 at 07:00 AM.
Instructor
Joined: Jul 2007
Posts: 898
Likes: 195
From: NJ
I assume you have the same rear diff as my 2005 so not sure how dirt gets in there unless someone messed with it inappropriately in the past. If you do a proper rear diff fluid change and the grinding noises continue then maybe you have damage. I have never heard one peep out of my rear diff ever. The person doing the service for you can tell you if they think the diff was low on fluid.
I really disagree that tranny fluid does not need to be changed. I have done about four drain refills of my tranny fluid in the cars lifetime. I like it that way - not a full flush which can be too "violent" but a simple drain refill where 2-3 quarts comes out and you put in the 2-3 quarts of fresh stuff back in. Trans is clearly smoother with some refreshed fluid in there every 30 k miles or so. Like I mentioned, even for my other cars where the OEM says lifetime transmission fluid, I don't believe it. That could turn out to be a pretty short lifetime ....
I really disagree that tranny fluid does not need to be changed. I have done about four drain refills of my tranny fluid in the cars lifetime. I like it that way - not a full flush which can be too "violent" but a simple drain refill where 2-3 quarts comes out and you put in the 2-3 quarts of fresh stuff back in. Trans is clearly smoother with some refreshed fluid in there every 30 k miles or so. Like I mentioned, even for my other cars where the OEM says lifetime transmission fluid, I don't believe it. That could turn out to be a pretty short lifetime ....
Driver
Joined: Oct 2021
Posts: 72
Likes: 33
From: Virginia
Just added the Revenol 75W-90 to the cart along with the washers. Found a really helpful video on the process and some important guide regarding the washer, making sure the car is level, and amount that goes in the differential. it looks like it needs about 2 quarts of oil.
Instructor
Joined: Jul 2007
Posts: 898
Likes: 195
From: NJ
Oh and I assume by your handle you have a 2003 so if you choose to do a trans drain refill, use Toyota T IV or equivalent. Later versions of the SC use a different Toyota Lexus fluid but the 03 should take T IV.
Driver
Joined: Oct 2021
Posts: 72
Likes: 33
From: Virginia
Found 3 different top quality makers for Diff Fluid and wanted to see what everyone recommends for our SCs.
REVENOL 75W-90 - Made in Germany. Ive used this for my truck (5.7 Tundra) in all 3, front and rear Diff and Transfer case.
AMSOIL SVGPK 75W-90 "Specific Uses: Heavy-duty use, High- Stress conditions"
Royal Purple 75W-90 "Specific Uses: Improve power and protection for heavily loaded gears in trucks, automobiles, and marine engines"
REVENOL 75W-90 - Made in Germany. Ive used this for my truck (5.7 Tundra) in all 3, front and rear Diff and Transfer case.
AMSOIL SVGPK 75W-90 "Specific Uses: Heavy-duty use, High- Stress conditions"
Royal Purple 75W-90 "Specific Uses: Improve power and protection for heavily loaded gears in trucks, automobiles, and marine engines"
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Thread Starter
Driver
Joined: Dec 2023
Posts: 65
Likes: 6
From: nv
I assume you have the same rear diff as my 2005 so not sure how dirt gets in there unless someone messed with it inappropriately in the past. If you do a proper rear diff fluid change and the grinding noises continue then maybe you have damage. I have never heard one peep out of my rear diff ever. The person doing the service for you can tell you if they think the diff was low on fluid.
I really disagree that tranny fluid does not need to be changed. I have done about four drain refills of my tranny fluid in the cars lifetime. I like it that way - not a full flush which can be too "violent" but a simple drain refill where 2-3 quarts comes out and you put in the 2-3 quarts of fresh stuff back in. Trans is clearly smoother with some refreshed fluid in there every 30 k miles or so. Like I mentioned, even for my other cars where the OEM says lifetime transmission fluid, I don't believe it. That could turn out to be a pretty short lifetime ....
I really disagree that tranny fluid does not need to be changed. I have done about four drain refills of my tranny fluid in the cars lifetime. I like it that way - not a full flush which can be too "violent" but a simple drain refill where 2-3 quarts comes out and you put in the 2-3 quarts of fresh stuff back in. Trans is clearly smoother with some refreshed fluid in there every 30 k miles or so. Like I mentioned, even for my other cars where the OEM says lifetime transmission fluid, I don't believe it. That could turn out to be a pretty short lifetime ....
Last edited by 430sc03; Mar 7, 2025 at 09:48 AM.
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Driver
Joined: Oct 2021
Posts: 72
Likes: 33
From: Virginia
I do agree with @OBP regarding the tranny oil change. I have a 2005 but have not changed it out just yet, thankfully for us, we still have a dipstick where we can smell and see the color of the fluid to gauge the necessity to change it. My SC only has 55K miles so not there just yet based on smell and color. I might consider doing that in the summer just to cover the next 50K miles. I did a drain and fill in my Tundra, a closed system, and was blown away at the color difference in field and smell.
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