After reading this thread, I'm leaning towards not doing anything about my differential fluid (I'm at 40k now in my '08 Is350). Also, on a similar note, not worrying about the transmission fluid change either. I've seen that debate in different places but each time, it seems the case for NOT worrying about doing anything about your transmission fluid wins out.

 

Which none of the ISx50s are.

The ISx50 calls for changing the diff fluid exactly never. Which is how often I plan to change it.

If anyone can point out anybody who has ever had a diff failure from following the manual in this regard please do.


The tranny is an even more extreme case in that not only does the manual explicitly state you don't change it, it's physically impossible to do so.


The diff fluid at least can be changed out, it's just that the manual never calls for you to do so and without a mechanical LSD back there I've yet to see any good explanation of why you should bother.

 

I would think that if Lexus, (because the Manual states that the WS tranny fluid never needs to be changed), should cover the tranny if a failure occurs because of fluid related issues. Just saying!

 

What kind of jack stands do you guys use? Mine doesn't have a deep notch and I'm afraid it will crush the extra long body panel that the jack point marking is on. They seems to be much longer than any other car I've seen in the past.

Ideally I would like to use the scissors jack to get the wheel up, and drop the wheel on some ramp or concrete tiles, so I do not need to buy another set of jack stands. Any other "safe" choice?

 

My e46 BMW 328i had "lifetime" transmission and diff. oils. I changed them both at 100,000km intervals and the diff. oil still looked mint. "Lifetime" oil is the manufacturer saving themselves money over the covered service period and protecting the original owners. Calling them "lifetime" fludis could very well be a nod to the dealer service network... gotta toss work their way at some point! It would be prudent to change these fluids period. The Canadian manual says 64,000kms for both as previously stated in this thread, I have no clue why it would be any different than US cars. My car by VIN is a "Destination: US" car, RWD with M/T.

 

I just changed my differential fluid yesterday on my '08 IS250 w/65k. The changing from gear to gear is A LOT smoother that is was before I changed it. It sure does make a HUGE difference in the quality of the ride. My fluid was really dark and that drain plug was covered in shavings. Normal, but I do feel a lot better knowing that that magnet is no clean and ready to pick up any other metal shaving that it wasn't able to pick up before.

 

replace it, find a good private/independent mechanic.

 

Although the manual states for the 2008 ISF to use 75w85, I see everyone is using 75w90 is it because aftermarket suppliers only make it in this weight? And I guess its OK to use the 75w90?

Also do you guys know the part number for the rear differential crush washer for toyota? I don't want to go to Lexus and pay $4.00 a washer!

 

Just finished the rear diff fluid change and I have no idea how JoeZ did it without having to remove the exhaust. The fit is so tight there was no way I was gonna even attempt it without removing the exhaust. As i was changing it out I was thinking to myself if only they made the fill and drain plugs on the left side of the diff. it would make it so much easier and hassle free.

 

you don't need to remove the exhaust if you have the standard ratchet extensions and universal joints. Now the 370Z differential that was a test in dexterity

 

will be replaced. That's how i did my camry, drained the fluid three times (drove a few miles in between) and refilled it with new fluid. I will do my differential at 100k miles.

 

Sorry to revive this thread, but has anyone with higher mileage had rear diff failures caused by not changing the fluid?

I'm only at 25K miles, but if there are issues with metal shavings (from break in?), I'd rather get rid of them sooner rather than later.

Or, just leave it until it breaks and then have a good excuse for a Torsen LSD.

 

^The break-in metal shavings were captured by the magnetic drain plug. It should look something like this :

 

I just recently replaced all the drive train fluids in my 07 IS250 AWD. It had 138K miles on it and I replaced the front/rear differential fluids and the transmission/transfer case fluid. I noticed a slight leak coming from the front differential. You can see the tread I made here:

https://www.clublexus.com/forums/mai...tial-leak.html

We put Amsoil 75W-90 in the differentials and after a ton of research, I found out that the actual viscosity you're supposed to use is 85W-90. Now a lot of people will say it's only when the oil is cold where it's thicker, but on another forum at a Mercedes thread, they proved that the 85W-90 was all around in all temperatures a thicker oil and possibly even non synthetic depending on the brand you use. I'm going to swap back to 85W-90 to see if that "band aid' fixes my slow leak.

I only leak 3-4 drops right after I park the car and then it doesn't drip again until I drive it the next day. It could be slowly leaking out while I'm driving so I don' t want to burn up my front differential if it's been slowly leaking while I drive. The capacity for the front differential is less than a quart I believe.

 

So today I took the opportunity to finally do the DIY rear carrier gear oil change. Was pretty straight-forward, as I expected. Instead of using a hand pump or some other off-the-shelf item, I went straight-up backyard mechanic and just used gravity and 6ft of clear tubing. Used Lucas full syn 80w-90 gear oil, and the right from the get-go I could tell it is smoother. So for those that don't wanna spend unnecessary funds on a "pump" you'll use once, twice...whatever, spend the $3 on tubing and do this :



Used some electrical tape around the end of the hose and wrapped it around the diff to ensure it didn't pop out of the housing during feeding.

Definitely worth the 1hr!