nautilex

Folks, what are your opinions on transmission coolers? Is adding one likely to reduce the risk of failures on the RX?

I bought a '99 RX to replace my Windstar minivan when the transmission failed this year. It had 345,000 km on it and I often towed trailers weighing up to 2000 lbs. Mechanics told me I did very well to get that many kilometres on the Windstar, as the Ford transmissions frequently die between 150 k and 200 k. One fellow thought the transmission cooler (part of the Windstar towing package) was a significant factor in the tranny lasting that long.

I have no choice but to tow with the Lexus. My other vehicle is a four-cylinder Mazda 626 w auto trans, definitely not a towing candidate.

salimshah

If you tow then cooler would be a must, [is part of the tow package].

For others, it might help. The cooler essentially helps in dissipating heat and with lower temp the fluid life is extended.

Where it may not help is the extended time to reach optimum temp. This causes the trans to remain in low gear.

Some one, please correct me .... there is no bye-pass to the cooler.

Salim

Lexmex

I agree...it is a must have.

If you visit the ES forum and do a search on this subject...a lot of people also want to get the cooler to help their trannies. Some of the ES models use a similar though slightly less powerful version of our 1MZFE engines.

This is a picture from the front on the passenger side. Will show a rear picture in the next one.

Lexmex

And this from the front passenger side wheel well.

TunedRX300

There is no by-pass on the cooler, also the transmission filter has no by-pass valve (like those inside engine oil filters). One never want either of these critical paths for ATF to be clogged.
One frequently omitted practice is to drain the ATF to get rid of metal debris inside the cooler and its hoses so ATF can circulate freely.
The other important thing to remember that magnets in the pan only attract ferrous debris, they do NOT retain copper shaving from bearings and aluminum particles from components inside torque convertor.
That is why I am seriously considering installing an inline transmission filter on the cooler return line to the transmission. Think about it, where do these Al and Cu debris go?

Lexmex

It would be a great idea to do an external filter. I though about the next time I do a drain and fill to use one of those coffee filters to see if any gold so to speak comes out in the filter...that would not of course attach to the magnets or even find its way to the bottom of the pan.

Lexmex

I want to add that this cooler does get hot...I usually have to toss a little water on it from behind when I arrive at the track.

nautilex

Thanks folks; Especially to lexmex for the photos. Because of the pictures I discovered today that in fact I already have a tranny cooler. I never would have looked in that location. I thought they were always placed in front of or just below the radiator.

By the way, does everyone have the issue of the transmission not shifting into 3rd gear first thing in the morning until you've driven about a mile?

l

Tammy

It is normal for the transmission to hang in second gear for a bit to assist in warm up if the catalytic converters. It will do this till the temperature gauge reaches the first mark.

Lexmex

I know about that all too well. I generally have to wait a minimum of 3 to 4 minutes when I start up my RX at the track before I can let her rip down the track.

97-SC300

iTrader: (17)

I am just wondering, my parents have 2000 toyota avalon and 2002 toyota sienna, which have the same engine as the RX300. Does anyone know if they share the same transmissions?

salimshah

To mimimize pollution, it is reccomended that ppl drive rather than idle to warm up. One of the possible cause of problem is when ppl live next to highway, and they have to merge in traffic, doing 60mph +, without allowing sufficient time to warm-up.

Is there a temp sensor to monitor trans fluid temprature? If so what does it control?

It seems the warmp up 3rd gear release is based on coolant temprature. [stand still idle should help the 3rd gear release .... well not the pollution]

Salim

Lexmex

There is an A/T Temp Light on the dash. When I start out in the morning. I just turned it on and a few seconds later back out and am on my way. I am usually a good half mile away before the temp. is good enough to open up the other gears.

varcity64

iTrader: (2)

i have a 99 RX300 AWD w/92k miles on the odo w/no problems thus far and i DO NOT like the things im reading in this post should i purchase an aftermarket warranty now??

Fern

No!,

just have the trani fluid properly serviced by Toyota or Lexus and keep receipts of trani service.