How to check condition of transmission fluid without dumping all the contents?
So I have been told I need to have the transmission fluid changed in my GX470 by the dealer. They have said that off and on when I take it in for an oil change or some other services since 60K miles. I have never felt a difference in the transmission performance and have had no 'quirks' with it like I have had with other cars when the trans fluid is nearing the end of its useful life.
So I am concerned that since it is a 'sealed' unit that has no dipstick to check the fluid condition, they have a 'safe' way to tell me I need an expensive service when I really do not. Is there a way to check the fluid condition without having to dump the fluid or have the chance to accidentally dump a significant amount of trans fluid?
I am not afraid to work on my cars (I used to work on my cars including my built up rotary with a street port) but have just been too busy to do that stuff for the past 15+ years and am starting to get back into maintaining my own cars again.
This is more of a time/mileage = it's time to change thing, than a visual inspection thing IMO. I recently did mine, via 2X drain & fills with a week of driving in between, so roughly 1/2 the fluid should be new. That's as far as I'm going to take it for the time being, maybe I'll do another in a year's time.
'04 GX470 - ML audio w/ RSES, 4300k HID, GROM USB2 w/BT, FJ Cruiser 6-spokes w/ Lexus centercaps, 265/70/17C Duratracs, TPMS disabled, weathertech mats & cargo mat
'93 Land Cruiser HDJ81 - 3X diff locks, winch, center console fridge, 285/75/16E Duratracs, 2.5" lift w/ Fox IFP V2.0, HID retrofit, IPF SuperRally aux lights, Aussie front bumper
'99 MB E55t AMG - 354hp/390ft/lb torque Daily Driver
So maybe the dealer is BS'ing me when they say my transmission fluid looks really dirty and needs to be flushed when I was at 60K. The car has not been run hard (no offroading, etc.) or has ever towed anything (no tow hitch).
A guy in the GS350 thread sent his off and they said at around 80k miles it was ready. I did my wife's GS350 at 85k and it was dark but was still very slick and appeared to have its viscosity. I did all 12 quarts.
the fluid needs analysis to know the condition. i would simply drain, drop the pan, put in new filter, refill, and send sample off for analysis. the UOA can also show internal damage like very high bronze, etc.
the condition of the oil depends on mileage, environment, and usage.
I can remember when BMW and Mercedes both went to the "lifetime oil" in their respective transmissions. This was more about marketing than reality, unless one considers about 120k miles to be the lifetime of the transmission. I'm saddened to see other manufactures follow along this path. Changing the transmission oil and filter every 60k miles is cheap insurance. If you do a lot of trailer towing, I would recommend a change interval more frequent than 60K.