I drive a 2015 GS AWD. I've owned it since new for (now) nine years. I don't drive a lot and currently have 48,000 on the ODO. At last maintenance (at Toyota dealer) they wanted to replace all differential and axel fluids (three of them) for $290. I see nowhere in the maintenance manual that ANY of these fluids need to be replaced, let alone ALL three! Is there any reason to replace all these fluids?

 

No, it is not recommended nor needed.

 

Why not just change it yourself for 30 bucks? Front diff takes less than 1Q and the rear is less then 2Q. I could see changing it due to age(Oil does breakdown), but mile wises I think you are good. My rule of thumb is if the stuff has a shelf life on the bottle sealed….it isn’t going to be lifetime in the diff/ATF working under high temperatures.

 

Almost 10 year old fluids. When broken in, metal and shavings and debris, got in the fluid. All fluids are subject to contaminations.

 

Service that car.

 

It's a Lexus, treat it like one. It will reward you with many miles, like it's still only a year old. Fresh uncontaminated fluids will allow it to perform the fluid driven function parts flawlessly.

 

So when the dealer quoted three fluid changes what was included with the two differentials? It couldn't have been the transmission/transfer case as that is a sealed unit.

 

I'm not getting involved in this! I'll be on my way...

 

Seems to me, you would want to ask them that.

 

I’d change the coolant and transmission fluid too

 

According to the service/warranty guide the transmission fluid cannot be changed and the coolant change should be at 100,000 miles; I'm not yet half way there.

 

Coolant becomes corrosive with age. Trans fluid can be changed. Just ask your mechanic and they’ll know what to do.

Source:

 

I have 192k on my car and have changed the rear differential fluid 3 times, the coolant once (it's overdue now) and the transmission twice, the last time less than two weeks ago. Every time I do it in notice the car drives much smoother and puts down power better, especially the rear diff change. The transmission fluid change is also totally worth it as the car shifts perfectly smooth. ONLY do a drain and refill no flushes and I would go to a reputable dealer for the transmission fluid change, just cause it has to come up to temp and they have test gear for all that.

I know people say "oh you don't have to do it" and I guess you don't the car will still move 😂 but it will be jerky and have shift flares after a while, aka not a Lexus.

I'm pretty "demanding" on my car so I try to maintain it well. Can't have it break down when you're traveling 100 Miles in 110 degree weather

 

The coolant initial factory fill is 10yr/100k, whichever comes first. It ages w/ or w/o use. I doubt it say the trans fluid CANNOT be changed. That’s flat wrong. It is often referred to as a “lifetime” fluid - lifetime being until the warranty is over. The book schedule is written to get you out of warranty with minimal free maintenance; it is not written to maintain the vehicle in top condition or for maximum longevity.

The initial trans service should be about now (60k is a conservative point to start; then every 30k after that: they are not wrong to recommend it). The transmission CAN indeed be ignored. It just depends upon how long you want to keep the vehicle and what condition you wan to keep it in. The diff fluids every 40k is a very good interval. Personally, after decades and decades of experience, I do the trans every 30k (just drain/fill), diffs around 40k, drain/fill radiator every 5yr/50k (after initial 10yr).

You are in fact lucky you have a dealership who makes sensible recommendations and a not unfair price, compared to what you hear from some. And as always, you can do it yourself very cheaply. Or ignore best practices and just let it go.

 

@bob256k - Please tell me more about this phenomena. I've never heard of this before from any reputable source.

What exactly did a fluid change actually do to bring about a condition where 'the car drives smoother and puts down power better'?

I've searched the entire Milky Way for how a car can 'put power down better'. I found a lot of information about traction and tires, and about weight and gearing - but I've found no advantage from changing any fluid, regardless whether the fluid is for lubrication or for cooling or for burnouts or for drinking.

I'm struggling to understand how and why this magical feat you posted about is actually accomplished. Help!
Do you think maybe this perception you have might be a 'fluid change' placebo effect that makes you psychologically think your proclamation is true?