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So I have a 2010 RX 350 AWD with the towing package and I live in Ottawa, ON, Can..(salt belt). I couple of weeks ago I notice a little puddle of ATF under the vehicle. Found it was the steel nipple, out of the radiator, developed a pin hole from corrosion.
(Side note: this radiator was replaced(all under covered under insurance) because of an accident my daughter was in about 3yrs ago. Doing this diagnosis, I found that a Chinese made aftermarket radiator was used as a replacement hence the premature failure. Not too happy about that!)
So I decided to replace the radiator again this time with OEM. This went well and a fairly simple job for myself.
As I was down there looking around, quite a few of the OEM spring clamps were fairly corroded and I wanted to replace them before they let go completely. When I removed one of them from the stock transmission cooler, I found another pin hole leak from that metal nipple. When I tried to remove the hose, the entire nipple came off with it. Argh!! I hate dealing with rust and corroision! Being 12years old and driven in our salty winters, it's lasted very well considering.
After looking into the cost of a new transmission cooler, I found that it's TWICE the price of an OEM radiator! That's insane to say the least!
So my question is, do I really need this cooler for just regular driving and the odd time pulling a small utility trailer/ATV? I'd rather not have to spend $1200+ on this little cooler if I really don't have to.
These Aisin transmissions are mediocre at best. They probably benefit from all the cooling power they can get. While my wife's 2015 RX350 FWD has the factory towing package, I would never tow anything with it. That is what my 1999 Ram is for.
Nope. Do some research and you will learn of their weaknesses. Yes, the ATF needs to be drained and filled at regular intervals. But if you drive these things like jackrabbits or do a lot of towing, the transmission will suffer from bore wear. Go to www.transmissiondigest.com and watch the video pertaining to the U660E Aisin transmission.
Yes I've read about the case bearing bore wear issue on the U660E. I also could not find any details on whether this issue also exists in the U660F model which is what my RX has.
Either way, any transmission out there has thier pros and cons. Honda's, for example, are considerably more problamatic than Toyota...
I'm just looking for an overall opinion on whether or not this cooler is worth replacing or just omit it completely. I don't abuse my vehicles and the most I'd tow with it is ~1300lbs(little trailer and ATV) on fairly level terrain. Use to tow the same weight with an 02' Maxima and a 95' Sunfire without any issues.
An alternative would be to get the cheaper radiator and also purchase an aftermarket external add on transmission cooler for under $200. These typically attach to the front of the radiator with screws and clamps or zip ties. You make some longer hoses to connect it to the transmission. I have done this on 2 vehicles, an old Ford Explorer and a Mazda. I like the low pressure drop design as it allows your transmission to heat up normally then when the fluid warms up enough the gateway opens to allow flow through the cooler. There are several manufacturers but I used these. https://www.trucool.com/products
You could also add a Magnefine 3/8 inch inline transmission filter at the same time.
If it was me I'd just bypass the cooler. The models without the factory tow package are still rated 1500# towing capacity, that should cover your towing needs.
One thing to consider, I heard the ATF cooler's other job is to worm up the fluid faster in very cold weather.
I also think this transmission is very reliable, never heard anything bad about them.
As you can see from these pics I just took of the cooler, this thing is so clogged up, I doubt it's providing any cooling to the fluid.
@Non I don't see how this cooler would provide any additional heat to the fluid. It's mounted away from any warm sources and there's no electrical components that's connected to it, only the in and out fluid lines.
This is my access point to the cooler for removal. From underneath the front of the vehicle. From the front of the cooler.
@Non I don't see how this cooler would provide any additional heat to the fluid. It's mounted away from any warm sources and there's no electrical components that's connected to it, only the in and out fluid lines.
I was mistaken. I got mixed up with my Ford Explorer which has the ATF cooler inside the engine radiator. Sorry.
Thanks so much for posting the pictures, I'll check mine to see if it needs cleaning
Looks like that external trans cooler is just for cooling using the air, while the one in the radiator does double duty. My Highlander and our two RX350s all have this external trans cooler (tow pkg standard in Canada) and the internal cooler in the radiator.
I think that external cooler could easily be replaced with something aftermarket, or even OEM if the bolts holding it on are not so rusted that everything has to be cut off the car.
I think that external cooler could easily be replaced with something aftermarket, or even OEM if the bolts holding it on are not so rusted that everything has to be cut off the car.
I was actually able to remove the cooler with no issues after a couple days dousing of Liquid Wrench on the two bolts that held in place.
I've also decided to just bite the bullet and buy a new OEM cooler to replace it.
This is the metal nipple that broke off in the hose from corrosion.
06-22-22, 07:01 AM
External transmission cooler really needed?
