bjz3638

Need advice on the following issue on our 2000 RX 300.

Had the vehicle since 32,000miles. now reads 106,000. transmission serviced twice by me. (standard drain and refill) Lexus service center always said the fluid was good for the life of the tranny. I disagree.

Current symptoms ( long winded but bear with me)

while driving last week I noticed the tranny had a slight slip between 2-3rd gear while under moderate to aggressive acceleration. does not slip much mabye 300-400rpm. In addition slipping is not present at all times. sometimes is slips sometime it does not.
Pulled dipstick, fluid dark in color ( not amber cherry) but then again it was never cherry in color from the day we bought it. I am thinking a transmission service and flush is in order? thoughts on this? or am I delaying the obvious that this tranny is on its way to the junkyard? anyone recommend a good competent service shop in the east phoenix metro? Lexus of scottsdale wants $240 to flush and drop the pan. They quoted over $4k for a re-built transmission. OUCH! I am hoping that this may just be some old fluid caught in the valvebody causing slipping???

Needing some advice.....

mikey00

I would first try cleaning the 2 transmission speed sensors and swapping their positions. It is fairly easy and has worked for me and others. The directions are here:
https://www.clublexus.com/forums/sho...=speed+sensors
If that fixes the problem I would do drain and fill immediately and then every 15K to keep your fluid clean.

lexus114

Yours slips from second to third,mine slips from first to second Maybe we can put our heads together and get one good transmission going.

Lexmex

Do you have AWD? Because if so the transfer case having old fluid can cause issues witht the 2nd to 4d changeover.

I'd also pull the battery cable and let the system reset and then drive normally and see if the 2nd to 3rd issue still repeats itself.

bjz3638

Yes Its AWD. Any links for Instructions to change the transfer case? ** FYI tonight I am going to try and clean the speed sensors. Is this something that you can get to without removing the airbox? or do I need to pull it off. I don't have the car here with me at work.

bjz3638

Mikey 00 I noticed the link shows one speed sensor. where exactly is the 2nd sensor? How can you just clean / swap sensors? are they exactly the same? assuming wireing harness remains in the same locations, just swap sensors from one hole to the other....... correct?

lexus114

Yes you do need to remove the air box (piece of cake) and their are two speed sensors.One is on top of the trans.under the air box.The other is toward the front at a 45 degree angle.

mikey00

Both sensors are mounted on the top of the trans. One sensor sits at a 45 degree angle facing the battery. This one is visible. The other sits flat and is directly under the air box and hidden by it. You need to remove the air box to get at these. They are magnetic sensors and you will most likely find some metalic fuzz on the tip. I just cleaned it off with a q tip. They are both the same and I just swapped them from one hole to the other. My reasoning was that if one of them was bad, the trans would still exhibit some kind of problem but it should at least be different then before I swapped them. If this was the case I would then buy new sensors. But after cleaning and swapping the problem went away and never came back. The link I provided didn't really have good directions. I have better directions at this link:
http://us.lexusownersclub.com/forums...717&hl=mikey00

bjz3638

So i read the directions and I see that when I drain the transfer case there is not a seperate "fill" plug for the transfer case, rather you add additional fluid to the transmission fill tube and its connected to the transfer case? Sorry for the abundance of questions but I am pre-planning on doing all these fixes today and want to make 100% sure I am doing this right.

Thanks guys... I will keep you posted on the upcoming speed sensor cleaning and tranny drain and fill. hopefully this will cure our issues.

mikey00

Yes, well sort of. You have to be careful here because names "front diff" and "transfer case" are used interchangeablly for some reason on the RX. I am not sure which one Lexmex was referring to in his post. As long as both drain plugs are 10mm allen, they both contain ATF and fill from the trans dipstick tube. The trans drain is horizontal and the transfer case (by my terms) is vertical and behind it. The front and rear diff (again by my terms) use gear oil and have their own fill holes and are not 10mm allen. At 130K my front and rear diff have never been changed and I have no plans of doing so. There is a sticky at the beginning of the forum with some good pics and directions.
Just a suggestion: I would do things one at a time so you know what fixes the problem. I would do speed sensors first and if they fix the problem, do a drain and fill and keep fluid clean in the future. If speed sensors do not fix the problem, I would do a little more than a d&f. Maybe the filter is plugged. I would drop the pan, clean the pan and magnets and clean or replace the filter.

Edit: I just re-read lexmex's post. Don't forget about his suggestion of disconnecting the battery cable. You may want to try this first, being that it is the easiest.

Lexmex

What I am referring to is this, https://www.clublexus.com/forums/sho...d.php?t=214000

When I have changed out my transfer case (and rear differential), I notice an improvement (faster shift) between 2nd and 3rd.

The transfer case you are referring to is what I call the front differential and that is related to automatic transmission fluid as shown here by TunedRX300, https://www.clublexus.com/forums/sho...d.php?t=220061

Of the two, I'd do the second one, the transmission first, that is the more critical component.

mikey00

So what I refered to as the "transfer case" in my post above and what TunedRX referred to as the "transfer case" in his how to sticky is the "front diff" in Lexmex's post and vice versa.

Lexmex

That's right.

bjz3638

Ok will keep you posted. I have no time tonight, I am working on getting everything to start early saturday AM on the job. sequence
1. disconnect battery cable for 10-20 min. re connect and see if that works
2. clean speed sensors on tranny. see if that helps
4 followed up with a drain and fill x 2. I have bought 9 qts of toyota type IV fluid. how much should I drive betwen drain and fills?

Hopefully this works. Thanks for everyones input. this site proves very beneficial.

Stay tuned

Lexmex

Drive at least 1 week between drain and fills.