Rx 300 Transmission

[chase73]

I have owned a few lexus vehicles, but never one with high miles. My daughter is turning 16, purchased a lexus rx 300 w/ 168,000. Well kept and clean. Wondering if i should service the transmission or leave alone, don't know the history of the vehicle. Acting a little funny when cold, on incline, etc.

[bufferdan]

Change fluid and filter. Drive for awhile and just change fluid again during next oil change. Id do that a few times til your getting clean fluid out :)

[lenore]

absolutely do not do a flush, I am on several Lexus sites and a toyota site. We have found that with high mileage, a flush will disturb debris and mess up the valve body...To many have experienced transmision failure after a flush...Do as instructed a drain, clean filter or replace depending on what type is on the car, and add fluid. Then drive for a week and drain and fill again...The fluid should be a nice red color after done...

[Filehorse]

Bufferdan and Lenore are all over this and I just wanted to chime in with full agreement. If the fluid has NEVER been changed since new and now has 168,000 miles on it, I'd also (and I have) drop the pan and change the filter and pan gasket; refill with T-IV ATF; drive it a few miles and repeat only the drain and refill parts of the procedure. I would not do any thing with the filter. I might do a 2nd drain and refill if I was so inclined. This will probably get you up in that 95% ATF replacement range and your transmission will love you for it. I would avoid a fluid flush (displacement) procedure. Lenore is spot-on regarding the risks of doing a fluid flush on a high-mileage transmission with original fluid.

NOTE: On my 2000 RX300 AWD, the transmission does not have a true filter but a metal fine mesh screen which only needs to be flushed (back flushed) with a solvent such as mineral spirits and then blow-dried with compressed air. If you have this type of screen, there is no reason to replace it. I got that bit of a heads-up from my Lexus parts counter when I asked for what I assumed was a paper-element filter.

NOTE 2: If this is an AWD model, while you or somebody is under the vehicle anyway, go ahead and change the differential gear oil and the transfer case gear oil. If it is the original lubricant, it's past time to change it. Most people don't keep vehicles long enough to worry about these components but you now have one in the family if it's an AWD. The good news is the cost to drain and refill the rear differential and transfer case if minimal.