b2884987

I plan on changing my transmission fluid by drain and fill. After warming up the engine for 15 minutes and draining the ATF, can I fill the ATF by removing and replugging the dipstick to measure and see if the ATF is at its full capacity? By then, will the engine be a bit cold that the measurement will not be accurate?

salimshah

Warming the engine does not wam up the fluid. You need to drive.

Just make sure the transmission housing should be warm to touch [not hot and not cold]. After draining, I suggest let the drained fluid reach room temp. Measure volume and dispose old fluid appropriately. Torque drain plugs to spec. Measure fresh fluid at room temp (match volume of drained) and add it through the dip stick hole.

Why this way ... I have never been able to read the level using dip stick.

Salim

serge99

Lexus RX300.. Is the transmission of 1999 the same as the transmission of 2003? Or does the newer one have some changes or improvements?

carguy07

There are some improvements on the later models.

danno52

Looking to change the transmission fluid on a 01 Rx300 awd, and I am just confirming before buying fluid.
So,
4.1 quarts in pan
1 quart in front transaxle/front diff
2 quarts in filler line
Was going to drop pan and filter, so I'm not sure how much more will drain out after this.
Could someone please confirm the total amount for this type of fluid change.

thanks, at 6.1 quarts without excess in filter and pan, so I would presume about 7 quarts or should I have 8 to be sure in case I waste a bit pumping it out of filler line?

danno52

One more question is do I need and friction modifier For gear oil in the rear diff and/or transfer case?

danno52

Need help asap, did a full trans/filter and cooler drain, my problem is 3 quarts came out of cooler and still no fresh fluid arrived? Should I keep pumping until new stuff comes out, I have 7 fresh quarts in, 8 have come out, with no fresh fluid out of cooler return line still, going to pick up another quart cuz I only bought 7.

Hopefully. Someone knows what's up, or can chime in.

LA4Mead

I use the cooler line to exchange fluid with new. I have done so since the year after Lexus replaced my trans with a new updated one from Kyushu. Mine is FWD/2WD. I exchange almost three gallons, if I recall correctly, before I start seeing brand new fluid. By about the 10th or 11th quart it starts getting brand-new fluid. It's an easy job, but I use a helper so I'm only drawing about a quart and filling a quart at a time to minimize air. I have a helper crank the engine and let it pump only briefly with a length of hose into a jug so I can see how much is draining and cap the jug with I've got a gallon. This works out nicely. There is still a little air introduced, so expect to top off slightly. It purges out itself quickly, just going through the gears. It's much less messy, seemingly a good method to use if you already have a good seal and no problems for which you need to change out your filter. This is not the same as a pressurized machine that "flushes" the fluid; you are just using the purge through the cooler line and topping off, and not changing your filter. If you have problems already, just drop the pan, change your filter, and refill.

On mine, this new updated (not rebuilt) tranny has been great. I'll keep doing this procedure every year or two, depending on how much I tow. I have an additional cooler, in addition to the factory "tow" cooler stacked in series, both with their own thermostatic (computer) fan in the fender. My fluid stays pretty clean and in good shape now. I have been using the Valvoline MaxLife full synthetic, a multi-vehicle spec fluid that includes type IV from Walmart, less than $20/gallon.

To answer your question again and the question of someone else just before, I exchange through the cooler line without dropping the pan and breaking the pan seal, and you can exchange 10-11 quarts (2WD with an extra cooler) before getting new fluid, because you are exchanging the fluid from the whole system. 4WD might be a little more.

The amounts you were stating were only enough for parts of the system.

I hope this information helps. And if I'm wrong about any of this, these are only my observations and I'm no mechanic. I welcome comments from anyone with more experience. Thanks.

LA4Mead

If you drained the pan first, then added fluid, then exchanged through the cooler line, you still have dirty fluid in the system from torque converter and other system parts. You may need more than 3 gallons to purge the system.

danno52

3 gallons to purge system? What, please explain.

I followed exact procedure of sticky but replaced a quart more to get fresh fluid at cooler line to no avail, someone, please help??

LA4Mead

I didn't look at the sticky; does it give an amount to purge the full system for AWD? I didn't know there was a sticky for a cooler line purge; I'll have to look that up. I have a cooler line set up to make this procedure easier/cleaner, and more accessible that I labelled when I added the redundant cooler, but it's pretty straightforward even first time. I'm pretty sure I remember it taking more than 10 quarts to get new fluid at the purge without draining the pan for my 2WD. I buy 3 gallon bottles, and have a little left to top off. I used to buy a case of 12 quarts from the dealer, but found that a waste. The Valvoline Max Life full synthetic fluid seems superior, is in better condition when I change it, and it's competitively priced. Less trash, too. I think it's $18 per gallon; more if you go to an auto parts store.

Does this make more sense?

FoxyRacer

Gosh, I hope you are still in this group.
I'm an old glorified parts changer, tech assistant. I am faced with a leaking transmission. It started leaking after a flush and filter change at a shop close by. Now I prefer to do my own repairs. But, I'm a recent AK amputee. My car started throwing a timing control valve code P1349 , as well as a couple misfire codes. The car was taken back to the shop and they said that my front seal is leaking. I don't have the coin to pull the transmission currently. So it sat in my driveway. The battery died, and I got it charged up Saturday. The error codes were gone. I drove it about 10 miles and then I noticed a huge puddle of transmission fluid under it all the sudden. You said you did all the work from the vehicle on the ground. I know seals can fail at any time. I just want to make sure that it's the actual front seal leaking and not a loose drain plug or transmission hose that might have been left loose. What would be ther best way for me to inspect the leak, without putting her on a lift. I have the tools. Just don't have the jack currently. Any tips would be greatly appreciated. Thank you

nzvlnr

You should be able to crawl under it. Take a look at where the oil is coming from. You may have to wipe it all down real good, replace some of the fluid ( prepare for it to come back out ) start it back up maybe run it through the gears in place to build pressure and shut it off and take a peek.

Broc

Just from experience and reading about RX 300 tranny issues on the net, I find that many issues and tranny's in particular are related to a ground fault between the ECU and sensor or solenoid.

On any vehicle, they develop ground faults as they age. Water gets into the ground wire contact points, etc. Almost all of these are crimp only wires. The battery terminals get cleaned at least as often as the battery gets changed. But teh ground points never get touched. Eventually the contact develops "crevice corrosion" which is actually a primitive semi-conductor. So about 0.3v drop across the junction and current limiting. This is one reason why cars start to feel "old". Lights dim, radios get more static, etc.

The answer is to renew the ground side so currents flow easier. there is positive voltage in a circuit to the device, but none on the return side. But still has to flow the same current. So to see is this will help, make up some new ground wires. I use #4 wire from the auto parts house, but whatever you can find is good. Make a lead to go from Battery Neg post/clamp to the engine and then on to the firewall. Preferably the alternator mount. *** these systems including the alternator voltage regulator need to "see" the same ground or they do strange things like overcharge the battery slightly shortening its life.

The new wire should be crimped and soldered to eliminate the possibility of crevice corrosion between the wire and the crimped terminal. And it should go to a clean surface where it's bolted down. A bit of Never-Seize at the bolt points does not hurt. Hood hinge bolts are a good contact point for the chassis. After installation you should see brighter lights, less CEL's and it may cure some tranny issues with teh solenoids not reacting properly

You'all might also want to read this discussion about tranny faults and diagnosis: https://gearsmagazine.com/magazine/c...hift-troubles/

So along with fluid changes, you'all might want to do a bit of wiring ...

maorsela

Lately when the car is cold here in Atlanta, it takes a few more rpm for my transmission to shift to 2nd to 3rd gear, i think it's time i do fluid change.

Scotty Kilmer did a video here on a 2002 RX300 (which is what I got):


Mine has 175,000 miles and I drive it 80mi daily to downtown Atlanta, and I drive like a maniac, so i better change the fluid.

He said 4 qts came out of his RX, so i assume he was working on the AWD, mine is the FWD and the manual shows 3.3 qts.

Should I bother with the trans filter? he said it's a metal mesh and no need to replace every time.