Threxx

I see no reference to either of these three items in my 99 GS400's maintenance manual as far as how often they should be done. It tells me to "check" these items quite frequently, but the actual items to be changed never specifically state to change any of these, all the way up to 150k miles where the book stops.

I know the trans fluid should be changed relatively often. I know many times cars don't really recommend PS fluid or rear diff fluid changes unless you just feel like spending some money or if you're having a problem with said items.

So what do you think? Unlike some of you () I'm on a budget here, so not only do I do all of my own service work that I possibly can, but I also try to avoid excessive maintenance. In other words I'm asking you to please not tell me to change my transmission fluid every 30k miles because while I know that may be safer than 60k miles, I'm trying to find a good solid medium that will keep my car running very well without wasting too much time or money.

I don't drive my car that hard at all, either. So keep that in mind.

Oh, and I was also wondering when you might recommend changing my coolant and plugs? The manual seems to recommend about every 30k for coolant and either 30 or 60k for plugs (I can't remember). Considering that much cheaper american cars like the Ford Taurus, Chevy Impala, etc usually recommend 100k or higher mile intervals for these items.... would it not probably be safe for me to wait 60k for coolant flush and around 90k for plugs (unless I started to get a miss or something)?

I only use the best oil (Mobil 1 5w-30 synthetic), and am very good about using quality gasolines and periodic fuel system cleaners as well as induction system cleaner, so my motor should be pretty squeeky clean.

ArmyofOne

im not sure abou tht ediff fluid, but the tranny fluid should be done a MINUMIUM of ever 2 years or 20,000 miles. an antoumatic transmissions WORST enemy is heat. it doesnt matter how many mile syou think you can go. by the time it bunrs, it is too late.changing it every 20K ensures you keep it blood red (like it should be).

a tranny drain and fill will cost you 30 dollars. replace the filter and do a flush evvery other drain and fill (every 40K) and yoru good to go.

i woudl think the diff fluid shoudl be done every 35,000.

PitBull

Follow the owners manual if you want to do the minimum. Sounds like all yours calls for is a check. I would do it at least every 60K miles. I would do a fluid exchange, not a flush. You never want anything but transmission fluid put into the transmission (never let anyone even the dealer put a cleaner in your transmission, it can make it fail in a few thousand mile). You can change the rear diff at the same time. Have your Lexus deal advise you regarding if your model has a filter in the transmission. Some do some only have a wire screen. If you do the normal drop the pan and change the filter you will only be changing a percentage of the transmission fluid but that can be enough to maintain your vehicle. My 2004 4runner V8 with the 5 speed transmission doesn't even have a dip stick and Toyota states that it never needs to be serviced unless you use your vehicle to tow with. If you tow it states that you should service the transmission at 60K miles (not a flush) but drop the pan, change the filter and add fluid. As you can see all models are different. About the power steering fluid?? I would not touch it. I've seen them suck the old fluid out and clean them and then add new fluid and afterward they end up leaking. I've never seen one fail if left alone and kept full.

ArmyofOne

well, typically, when a flush is done, its done with trans fluid.

the drain the fluid out of the pan. then they pressure flush fresh fluid through the trans for 2 cycles on their machine, then they stop when full.

nothing other than ATF should ever go in you rtrans...ever.