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How would you suggest to "inspect" differential fluid? Are you taking samples and sending it to a lab for proper analysis? With that effort, why wouldn't you just drain and fill it? Front+rear diffs combined takes about 3qts of oil and this is an easy DIY job that can be done in <2 hours even for a beginner.
Why do any other cars with differentials specify change intervals? Are the Lexus differentials that much different from every other manufacturer or the Lexus fluid is that much better than anything else when it's not even synthetic? With differential oil, the first drain is especially important because most of the wear occurs while the car is broken in, and that metal stays inside. If you are lucky, the magnetic drain plug might capture some of it, but otherwise that metal stays inside meshing against your gears.
You may be right that differential gear oil probably doesn't face the same amount of high temperature than tranny fluid, but the mechanical stresses inside differentials are also much different from those of a transmission and that's what will contribute to shearing and reduce protection. That's why the transmission and diffs require different fluids to begin with.
If you go by the manual, I think the brakes are also "inspection" items - fairly certain that doesn't mean "no replacement" required.
In my time, I've changed the power steering, brake, differential, automatic/manual transmission and transfer case fluids on many, many vehicles. Some had over 200,000 miles on them with never a fluid change. I don't recommend it any more than I would recommend 20,000 mile oil change intervals.
Differential fluid will be dark after a few thousand miles regardless just from heating the fluid and running it in the differential unless you thoroughly degrease the case. The wear particles from break in are very small and pose little additional wear to the ring and pinion. As long as the seals don't leak and allow it to run dry, it will not overheat and ruin the gears, bearings or seals.
Transmissions, as long as they are run at the proper level and the filter is not plugged, also can run for a very long time. Towing is hard on them and will age or even burn fluid much faster. That requires more conservative (lower mileage) change/check intervals.
On my Lexus GS350 AWD, I do not plan on changing any of the non-engine fluids until 100,000 miles, assuming I keep it until then.
In my time, I've changed the power steering, brake, differential, automatic/manual transmission and transfer case fluids on many, many vehicles. Some had over 200,000 miles on them with never a fluid change. I don't recommend it any more than I would recommend 20,000 mile oil change intervals.
Differential fluid will be dark after a few thousand miles regardless just from heating the fluid and running it in the differential unless you thoroughly degrease the case. The wear particles from break in are very small and pose little additional wear to the ring and pinion. As long as the seals don't leak and allow it to run dry, it will not overheat and ruin the gears, bearings or seals.
Transmissions, as long as they are run at the proper level and the filter is not plugged, also can run for a very long time. Towing is hard on them and will age or even burn fluid much faster. That requires more conservative (lower mileage) change/check intervals.
On my Lexus GS350 AWD, I do not plan on changing any of the non-engine fluids until 100,000 miles, assuming I keep it until then.
2015 RC F with 24,000km (15,000 miles) DD. I am not hear to argue about the science or Lexus "sealed" transmissions. This weekend I was bored and dropped my rear diff fluid, and refilled with almost 2L (1900ml) Full Synthetic 75/90. Took like 10 minutes. They longest time was to lift it in the air to be able to get under it and have the car level. I did this with lifting each corner with my floor jack and then putting a Rino Ramp under each wheel.
Since I had my car in the air level, I decided for fun to drop the transmission fluid out of the pan. The refill plug is on the driver's side 24mm bolt. I went to Lexus and bought 3 one liter jugs of Toyota WS ATF fluid, as I rather pay a little more and not risk warranty as I have an extended warranty until 2023.
I should mention, due to the location of the rear diff and transmission fill hole, you definitely need a hand operated pump to get the fluids back in.
The magnetic plug in the rear diff had a decent build up of metal filings and was fairly dirty. The trans was not bad, slightly dark and maybe didn't need it but that's OK. I will do it again in a week or 2 with another 3 Liters, now that I know how easy it is to do..
So with the transmission, did you do the "drained fluid, measured it, then put exactly same amount back in" trick?
Adding this from the 2IS forums for the original OP of this thread. Maybe he can add the pics to his post. It shows the Transfer Case does share the Transmission Fluid.
In my time, I've changed the power steering, brake, differential, automatic/manual transmission and transfer case fluids on many, many vehicles. Some had over 200,000 miles on them with never a fluid change. I don't recommend it any more than I would recommend 20,000 mile oil change intervals.
Differential fluid will be dark after a few thousand miles regardless just from heating the fluid and running it in the differential unless you thoroughly degrease the case. The wear particles from break in are very small and pose little additional wear to the ring and pinion. As long as the seals don't leak and allow it to run dry, it will not overheat and ruin the gears, bearings or seals.
Transmissions, as long as they are run at the proper level and the filter is not plugged, also can run for a very long time. Towing is hard on them and will age or even burn fluid much faster. That requires more conservative (lower mileage) change/check intervals.
On my Lexus GS350 AWD, I do not plan on changing any of the non-engine fluids until 100,000 miles, assuming I keep it until then.
i have a 2008 is250 with roughly 200k miles on it. All transmission and differential fluids never changed before. Haven’t had any serious problems with the occasional less than smooth shift here n there.
Would you recommend I change any of the fluids?
Is it something that anyone can DIY?
If so, do you recommend any specific brand of fluid?
Would it be highly recommended to take it to a lexus stealership and get it done there?
thanks for your time and input (or anyones for that matter who wished to chime in)
i have a 2008 is250 with roughly 200k miles on it. All transmission and differential fluids never changed before. Haven’t had any serious problems with the occasional less than smooth shift here n there.
Would you recommend I change any of the fluids?
Is it something that anyone can DIY?
If so, do you recommend any specific brand of fluid?
Would it be highly recommended to take it to a lexus stealership and get it done there?
thanks for your time and input (or anyones for that matter who wished to chime in)
I must confess, I changed my fluids in 70,000 miles because I was bored and wanted to play with my lift.
It is a DIY project if you are able to get the car level and can follow basic instructions. The hardest part is getting the fluid back into the pan with a pump and then checking the fluid level at the proper temperature. If you just do the trans the one time, you'll replace at most 1/2 of the fluid (less than a gallon without the pan) and that's enough to replenish the fluid. I used the Torque app on my phone with a Bluetooth OBDII dongle. I confirmed with my no-touch infrared gun.
At 200K, I would change it if you plan to keep it longer. If you plan to trade it soon, I wouldn't bother if there are no issues. That's what I'd do if it were mine.
Thank you for your response. I will just hold off a little longer and use the funds for other purposes. Who knows, maybe I’ll change out the whole motor and transmission someday! ;D
The Lexus Scheduled Service Manual indicates only 'Inspection' of Front Differential (AWD) and Rear Differential through 150,000 miles with no replacement of (gear oil) fluids. The transmission (which includes the transfer case for AWD) is not even mentioned in the Lexus Scheduled Service Manual through 150,000 miles.
If you want to replace fluids before Lexus recommends doing so - you are far (FAR) better served by replacing the transmission fluid before replacing the gear oil in the differential(s). The transmission has many times more parts and moving pieces compared to the differential - with many of the transmission parts required to operate with exacting friction parameters unlike a differential's simple ring and pinion gear. And, the transmission is subject to much higher temperatures compared to the differential.
If I was planning to keep the car beyond 150k miles I would change the transmission fluid at around 100k miles. However, I would not replace the differential gear oil.
I did my transmission fluid at 25000 miles and at 50000 miles Both times it was dirty and I like to put it in brand new fluid . I did my rear diff because it was the easiest for me to find and the fluid was Perfect and Beautiful didn't need to drain but I opened it up so I put it in a new stuff anyway left the front one Alone because of this . It is not hard just get a decent pump. I want manual transmission guy and I hate automatics and I don't trust them because of childhood trauma but if you really concerned loosen the drain plug and see what comes out drain a little send it off to Blackstone and then no for sure. I wouldn't be able to sleep if I went a 100000 miles on transmission fluid Somebody contacted AISI N the manufacturer of the 6 speed tell me the internet somewhere and they said to change the fluid at like either 30 or 60 so I'm doing every 25000 just coz It's like next to no money so it makes me feel better but your car do what you want I'm OCD that's my 2 cents f*** it's a Toyota probably run forever if you didn't do anything to it period. I'm 50 and I want this to be my last car. Might try to find another one and just sit on it because as far as I'm concerned it's the Perfect Sedan I was Always a Beamer guy but Lexus all will Drive is supposedly the best system way More durable than extra Life especially because it's lubricated with the transmission fluid so you get like 9 or 10 l of fluid instead of 1 leader in the extra Drive transfer Case so that Alone is Wicked plus it's planetary gears and not a bunch of frigging clutches. New to the forum so be gentle
02-28-18, 01:37 PM
