RA051823

I decided to change the rear differential fluid in my wife's 13' GS350 AWD and decided to make a how to video on the process. It's a very easy service to perform and if you change your own oil you can change the diff oil with ease. Hopefully it will help any of you who want to tackle this service yourself. I like to change my differential fluid every 40-50k miles to keep things fresh.

richard203

iTrader: (1)

Now u can do a tranny fluid change

rockydog

Great video.

Surprised at the amount of rust present.

RA051823

When the car hits 60k I plan on doing one. We have a year before that happens.

A lot of it is superficial and easy to clean off. After I made this video I taped off the diff, sanded it down and used restoleum and it looks like new again. If you keep on top of it you can manage it. Welcome to Michigan...

AJLex19

I don't recall seeing anything in the maintenance schedule for the '13 GS350 AWD stating that differential oil needs to be changed (only an "inspect" item appears for each maintenance interval which is a little odd).

Is it just a good practice to change it every 30-40k miles or so even if there are no symptoms of a bad/poorly lubricated differential?

shurik74

iTrader: (5)

Great video! Thanks for taking your time and doing this for CL members... I plan to change mine when 20K hits, it's never hurts to do so, better for a car

RA051823

You’re correct Lexus only recommends to “inspect” these fluids at regular intervals. Lexus also states that the transmission in the GS350 is a sealed unit and requires no fluid changes either. Ask BMW how that worked out for them. In my opinion there is no such thing as lifetime fluid. If you’re like me and keep cars a long time its cheap insurance to keep the fluids fresh and clean. After all, these fluids are the life blood and changing them at regular intervals will insure longevity. Did you notice the magnetic drain plug I pulled from the differential? There were quite a few metal particles/shavings from the gears wearing themselves in which is completely normal in new differentials and is the reason why I like to do regular change intervals. I like to change my differential fluid every 40-50k miles on all my cars. The material cost was only $20.00 for two quarts of gear oil and is easier to perform than an oil change. In my opinion its a no brainier if longevity is key!

RA051823

No problem! Love your signature. "BMW is new money, Mercedes is old money, and Lexus is smart money."

BMW = Break My Wallet!

AJLex19

Makes a ton of sense - just spoke to my personal mechanic and he said "it can't hurt to change it." He also said that he wouldn't "inspect" it, he would just change it at 40k miles if it was never done. Since my car is at 47k, i'm definitely going to have him take care of it the next time i get service...Thanks for the info!

RA051823

Smart move!

er34

Great video! Wish I had myself a lift as well, this job is so much more difficult when you are working with just jack stands.

How much of the 1.43qt actually went in?

Did you do the front diff as well? I have trouble finding the 80w90 that Lexus calls for for the front.

RA051823

Thanks! Yea the lift comes in handy. When I bought a Aston Martin DB9 I didn't want to chance damaging the monocoque chassis with my jack and jack stands so I bought a 4 post lift to do regular maintenance on. It ended up being the single best purchase for my garage and so wish I would have done it sooner. It makes life so much easier when doing routine maintenance.

As for the differential service, I think the longest part of the job will be getting the car on jack stands. After the car is lifted its all down hill from there. If anyone knows I would be curious to see what the dealer charges for this service. I think its easier than an oil change.

The manual was pretty accurate in the amount it took. You will know its full once fluid starts coming out of the fill hole. Just wait till the fluid stops, then button it up.

I had a tough time locating the 75W85 for the rear diff but ended up using Mobil 75W90. As long as the oil is GL-5 compliant you will be ok. When I do the front differential I will make a video. I believe Valvoline makes 80W90 gear oil that is GL5 compliant? I plan on using Mobil 75W90 in my front diff too.

er34

Thanks. I had them mixed up, the 75w85 was the one I had trouble procuring(the dealer doesn't even carry it). Seems most people went with the Mobile 75w90 just like you did.

AJLex19

I just had the rear differential fluid changed on my AWD '13 GS. My mechanic said the oil was really dirty/black and it was a good idea to change. He used 75w-90 Mobil 1 synthetic GL-5 gear oil.

He had some trouble with changing it on the front differential as he said he could not open the plug (not sure why). I told him not to mess with it and that I would take a look online for some more resources.

Dan: Any insight into where the drain plug vs fill plug is on the front differential?

RA051823

No, I haven't even looked into the front differential yet. When I do, I'll be sure to let the forum know. It should be as simple as the rear though.