thomas1

I decided after loosing my transmission on my Old RX300 that being overly cautious with the fluid quality on the transmission is a cheap insurance to longevity. With our case and driving a lot 25k or 1 year is a great schedule to reach this goal. Since I change fluid myself the cost is minimal. As for the 1/2 quart, well I can only think of debris or expansion from heat. Mine has not exhibited that much extra. We now have 140k miles on the vehicle and knock on wood so far good. With my Sunday discount at my local Toyota dealership I have been getting the fluid for $9.5 per quart. I will say if you have AWD that the rear fluid is nearly always pristine so maybe a 50k or more on the rear is adequate. But the front is getting new fluid every 25k or 1 year.

jimboesfo

Thanks for the insight. I think I'll move the next change up to the 25K interval and see what the lab analysis shows. I was able to get the Toyota fluid for $8.20 per quart at CARQUEST auto parts store. They have Honda ATFs as well.

NateJG

I'm a bit puzzled by the lab's report of metals in the oil. Being a gearbox (as opposed to an engine with soft bearings and, perhaps, aluminum cylinder walls), I would expect that the "metals" would be from gears and/or bearings - and here's what puzzles me: I would expect that those particles would likely be captured by the gigungous magnets of the motor - and not show up in the oil.

Any thoughts?

smassey321

My thoughts are the metal comes from either the clutches or the drive chain. It is more of a differential than a transmission. The gears are fixed and don't change.

I did my first change 60k and the oil was pretty dirty. I did the 2nd at 45k and it was still dirty. I will do my next one at 1 year and see how bad it is. For $40 it is worth it.

jimboesfo

I'm not sure of the source of the metals. I've included the detailed analysis so you can draw your own conclusions.

jimboesfo

Just did the second transmission fluid change at 14,000 mile interval. The fluid had a cloudy appearance so I decided to have it analyzed. Here are the comments from Blackstone:

Metals look much better this time as wear-in material washes out. Aluminum is the only one that's still
high enough to mark, but as long as it continues to improve, we won't worry about it too much. We're happy
to see that you changed this oil since insolubles (oxidized solids due to heat and use) were high at 0.1%. If
the filter wasn't changed last time, then that could explain it. At least they didn't cause excess wear, so they
don't seem harmful, but it would be nice if they read a bit lower. We'll look for aluminum and insolubles to
improve next time.

I'm a bit concerned about the insolubles result indicating the fluid is getting hot. I will definitely be changing it again in another 15K.

thomas1

Thank you for posting analysis. I have scheduled my changes for once a year or every 15k miles. My RX400h has 162k miles and the last fluid (last week) was very dirty in condition. We drive the vehicle moderate to hard. We don't drive for fuel economy.

NateJG

Jimbo:

Thanks for posting your results. I'm just now able to read them, as my aged iPad wouldn't recognize/read the file; and I'm on an even older ThinkPad - but at least it likes the file.

Have you considered sending in a sample of the virgin fluid - so that the oil sample company has a baseline? Or, are they intimately aware of it already?

I had the luxury of being intimately involved in the development of proprietary synthetic gear lubricants back in the 90's ( http://www.eaton.com/Eaton/ProductsS...ants/index.htm ].

I am a firm believer in synthetic lubricants for gearboxes as a result (for example, in just our drive axles, we were able to go from a recommended gear oil change from 25,000 to instead 250,000; and our parts and service warranty went from -- can't remember -- to over 500,000 miles; and in our transmissions, we went to a 500,000 mile warranty -- due to a great degree to the superiority of synthetic gear oil in place of then-conventional oil).

The use of similar oils/specifications quickly became the industry norm.

I cannot find my used oil procedure; and in a quickie search of the company's web I couldn't find what I was looking for -- however, I'm attempting to contact an also-retired member of the vendor with which we developed the additive package -- in hopes of reminding myself of what to look for in the lab reports.

In any event, comparison to a baseline sample of new oil is of great interest to me - as I plan on changing the oil in my 450h's gearboxes soon (I'm at 33K; and am paying attention to your observations).

My interest is piqued by the apparent difference in visual condition of the oil in the front vs rear gearboxes -- though it's not surprising that the rear would be cleaner, as it's not used as much.

There are a couple more tests that I'd like to see the lab do -- but until I can "find" some old notes (didn't/couldn't keep company proprietary stuff when I retired -- but there are lots of customer documents out there once I hit the right contact).

It is also important to know a bit about the makeup of the gearbox - the specific metals used - where they're used (bearing, shaft, case, etc.); and from what might the dissolved solids come -- for example, is the color change due to the insulation on the windings of the motor? Is the change due to heat? If so, how was that determined? What metals are included in the oil itself? Certain metals become lubricants when compressed - zinc and copper come to mind; and there are several in EP gear oils, as the hypoid pressures are substantially different from that of spur or spiral bevel gears -- and from what I've been able to see, the planetary gearset is not a simple spur gearset.

If anyone reading this has access to the TTMA Recommended Practices manual, perhaps (s)he could post one of the recommended practices for used gear lube testing. We used Cleveland Technical Center and (cannot remember in Indianapolis) for the fleet/field testing of thousands of samples; and truck fleets used myriad labs for their testing.

There were three distinct levels of testing - ranging in intensity and cost (were between about $10 and $40 each, depending upon whether or not a spectrum analysis was specified, simple "crackle test" for water, vs quantification, etc. Truck drive axles "breathe" in/out air as they run hot during the day and cool at night. The breather vents allow in moist air - or, in worst case, they are in the spray path of tire wash (that's why vents are often plumbed to where they open high in the frame.

Are our transmissions sealed? Are they vented? Is there a difference in experience in soggy Southern Florida vs dry Canada or Arizona? A really wide area analysis of many vehicles and vocations can really tell a story. There are specific waxlike temperature sensitive paints that can be used on the surface of a transmission to show that a specific heat level was violated -- and, given the possible HP of the onboard computers -- I'll bet my last $0.05 that some software geek at Lexus has already programmed in populating a histogram of temperature and torque and who-knows-what-else data which is sent back to the Mother Ship for analysis.

Thanks,

NateJG

thomas1

I found it probably not necessary to change rear fluid very often. The fluid looked (I know appearance) as good as the new fluid. The front is interesting at how dirty it gets. I am on my fourth change with the first being at 89k miles and I now have 161k miles. Hopefully an once of prevention will help.

NateJG

I took a side trip to my local Toyota dealership today (my Lexus dealer is ~150 mile round trip; and Toyota is about 20 Miles round trip). He will change my engine oil and rotate my tires for about $84; whereas it is almost double that (not counting travel) at the Lexus dealer.

He also gave me a quotation for changing the front and rear gear boxes at around $150. I think he meant total for both including labor; however, that figure is painfully close to the $150 for oil plus $150 for labor (total ~$300) for both gearboxes that I got from my Lexus dealer.

I'll call and confirm that next week.

Thomas: There's a very widely used (albeit hugely unscientific) test that I wonder whether or not you happened to perform it:

Rub the used oil between your fingers and feel for any grit or lack of lubricity.

Did you notice any difference between the new and used oil?

thomas1

Since I just changed it, might be awhile, but Yes I will try that. Darn I just recycled the drained fluid. I might change the fluid later this summer as the fluid was much darker than previous at the change interval.

katzjamr

I want to do that to my 400h, the dealer, who will do anything else on the car will not change the tranny fluid, I just don't believe it lasts the length of the car life, have 135K now.

NateJG

It's Lifetime Fill -- I just want to extend the lifetime (grin).

The way I look at it, lubricant changes are the single easiest thing that a user can perform on a piece of machinery -- and the lack of good lubrication is an equally-easy way to shorten the life of said machinery - so I err on the side of caution.

WolfyLS460

I just had my ATF changed at a Toyota/Lexus shop for $60.

thomas1

great price considering the fluid is around $10 per quart....