Hello,

I've been looking around at RX350's and learned about the "Lock" button which forces all-wheel-drive until ~30 MPH.

If you exceed 30 MPH, it appears to disable the lock, and go back into "normal AWD" mode, which means FWD most of the time.

I am wondering if there is a way to override the 30 MPH limit, and thus force the RX350 to stay in all-wheel-drive mode all the time?

Any thoughts would be welcome. Thanks!

 

The AWD lock is meant to help at low speeds, such as getting out of a parking place in the snow or ice. Regular AWD in a snowy stuck situation may shift power to the slippery wheel, giving you less traction than in the lock mode. I think operating the car in LOCK over 30 MPH would tend to make the car squirrelly and on dry pavement wear out the tires and drivetrain components. I'm curious as to why you want to LOCK the AWD all the time.
Ray A.

 

No, it is not possible. The AWD system is not designed for it.
Your best bet would be to buy a Subaru.

 

we just got through a cold and snowywinter here and i had no problems at all. didnt even have to lock in the rear. took it out of traction control a few times just to see what difference that made. but it was just fine in regular awd mode.

 

It does fine in snow, especially with snow tires. But it's not exceptional.
Full time AWD is more capable, stable and fun at higher speeds. But we're talking a whole different architecture here, something RX can never be.

My STi, which has one of the best AWD setups, doesn't drive itself through snow, it teleports.
It claws its way through and springs forward where it needs to be.

 

like i mentioned i had absolutely no trouble. and that was in 6" plus of snow going up n down hills etc. did everything i asked it to do with no complaints at all. i dont know what else i could ask for? and a superior highway cruser. works for me. sounds like your more of a subaru enthusiast

 

And, the best part is the Lexus won't blow a head gasket trying to do it. Can't say the same for the Subaru!

No, but in all seriousness, why does the OP want to lock AWD? IMO, there's no need.

 

Different needs, my friend. I demand more from my vehicles and can appreciate better/proper architecture. Very few drivers out there will care about such things, and that's what the bottom line is all about. It is a little sad watching RX stay in FWD mode when going through slush on the freeway. But it is what it is. It gets the job done.

Been a long time Lexus enthusiast. But I feel abandoned as Toyota is in business of building reliable appliances and that is just not good enough for my DD.
RX on the other hand, fits the bill well when it comes to hauling family around and I want to be isolated from the driving experience.

If STi does indeed blow a head-gasket, no big deal. It is not tuned so, the chances of it are low. While it stays this way, it is under warranty for 5 years/60K. In either case, I would fix it and trade it in for a Bimmer.

I will say this, though, when I was pushing stuck vehicles out from a snowed-in parking lot and was asked where I was stuck and if I needed help, I just had to say I drive a Subaru. The reply was, yeah, those don't get stuck.
When we were done, I hightailed my way out of there.

 

I thought second generation was all time AWD, no? I don't recall any button on my previous 2004.

 

I was not aware the RX done this so I appreciate you asking this on here. I live in an area where we have 18-24 inches of snow on the ground and living out in the country 4wd is a must. The fact the RX dont stay in 4wd like a 4wd should should makes it worthless in my book.
My 4Runner with a set of duratrax has plowed through snow driffs over my hood like its nothing and driving though a foot or better is like its 3" max. If I had to travel -30 mph all the way to town I'd sold this thing after arriving.
Thanks Lexus but Ill move up to a real 4wd you can keep this city hound you built for already plowed streets. Mall hopper for sure and its a shame it ever wore an AWD badge.

 

LoL! The GX and LX are right there, for you. Just bring tens of thousands of extra dollars.
My RX pushed through 16" of fresh snow after a huge storm with zero issues this winter.

 

The RX AWD models always "stay in the 4WD mode", the fact is that you can't turn it off. It's an automatic AWD (like all cross-overs) so the computer decides when AWD is needed and when it's not needed.
Many people are confused by this "AWD Lock" button, but the function of this button is to bypass the automatic control, and send equal amount of torque to all 4 wheels. This helps to get out of mud or deep snow.
Of course any SUV on a truck frame, like the 4Runner or the Lexus GX, with "real 4x4", will be better in deep snow and off road driving.
My 2002 explorer 4x4 beats the RX in the snow easy, But I like to drive my RX, and so far I never got stuck.

 

I have both an RX and a GX, both 2007, before the RX had the lock button, so, I'm jealous! If you understand 4WD, you will know that it denotes a center differential lock. Unless you are Baja racing, you don't need this over 30 mph. If you are really serious with offroading, you also want a front diff locker and rear diff locker for right left matching (but not in an RX). They call that triple locked, as there are potentially three differentials that can be locked for rock crawling. 4WD is simply the center diff between front axle and rear. So when it's locked, you aren't supposed drive on a paved road, it will tear up your tires, and a front rear locker will seriously tear up your tires.

From my experience with the GX, it is unique because it is one of the few AWD that has 4WD lock. In contrast, Tacoma and 4Runner are usually 2WD/4WD. This is typically better for towing to have the drive axle at the rear, but the GX and RX both tow very well, 350 is better, but I also had a 400h, which performed well for towing despite a CVT.. The GX also has ATRAC, full time when needed in 4WD. Atrac is an electronic version of triple locked using brakes to slow a wheel that is up in the air and equalize right left, and works quite well from my experience.

I'm short, enjoy AWD, and be glad you have a center diff lock on your RX for when you get stuck.

 

Actually the RX and Rav are more fwd than 4wd and why they don't stay in fwd past 30mph. If you notice the engines are sideways (fwd) that tells on it there.
Ive had most makes of 4wd trucks and Jeeps with detroit lockers to old Dana's galor over 40ys yrs and although its true running one in 4wd on dry pavement is bad on most 4wd systems there are many full time 4wd vehicles that do it very well with no issues at all.
Wifes 2007 V8 4Runner with full time 4wd (not AWD) now that SUV surprised me many times with its fwd capabilities. They drive like a dream in 4wd down interstates at 80mph.
Im actually running the Duratrac tires I ran on that 4Runner for over four yrs on my Tundra today. They've been on my Tundra almost 4yrs now too and I still run interstate 80mph almost daily. A lot of tread left yet & no suspension issues on a Toy 4wd here. People all laughed at the old Eagles but that Chrysler Torsen 4wd system sure changed the game for factory 4wd setups, that 4Runner went everywhere my other stock 4wd trucks did, made in/out every fishing hole & my hunting areas too. Not a winter went by that it didnt leave lines of All/4wds at the bottom of the two huge snowy/icy hills on the way to work..lol Even 2-3ft snow blizzards here with snow over its hood was no match for it.
I drove right past all those 4wd's many times sitting at the bottom wishing & watching. I even stopped at the stop light on top of the biggest hill and go again on green to pizz them all off as they waited for me to fail & back down it like they all done. It never failed me once I swear..lol.
Being full time 4wd it had the yaw sensor that straightens it up automatically in a nanosecond before you can blink if it slides sideways on icy overpasses, that feature saved more lives than we'll ever know. Had to wire a button to bypass its safety stuff so I could play in the mud/snow, easy ten minute job..lol.
The Rx/Rav is different than other 4WD Toyota makes, more like the fwd/AWD Camry, has a button to play with...lol.