I have never liked the "comfortably numb" electronic steering in my wife's 2015 RX350 FWD. If your tires and suspension components are in decent shape, there is probably not much you can do about it if good ol' fashioned conventional steering rack feel is your goal.

 

I drove a 2011 RX350 and a 2014 Lexus RX450h (which I own now) and the sport mode in the 2013+ RX is considerably heavier than the 2010 - 2012 RX standard steering with both on 19 inch wheels and both on Michelins. It was one of the reasons why I wanted to go with a 2013+ model year because of how rigid/stiff steering feels especially in sport mode. I use 43 psi cold all around and in sport mode, the steering is heavy and precise. I have the 19 inch RX450h wheels so the lower profile tires also make a difference so yes, 19 inch wheels with thinner aspect tires will make a difference in how the steering loads up lock-to-lock.

 

Mine are speced at 33psi. If you are running 43psi -> +10psi (+30%), you would be getting better mpg, poorer braking, poorer handling and abnormal wear [middle of the tread wearing out]. Since the tire rides on the middle portion of the tire, the steering should be more squirrely . I too push it on the positive side but stay below +10%. In any case, its your vehicle and you must have made this choice after fair bit of driving.

Salim

 

My extensive experiences are quite different from what you describe. I have A/S Michelin Premier so here are my experience with experimenting at 35 PSI, 39 PSI and 43 PSI

MPG - No noticeable difference between the three. About the same at higher tires pressure. Did not notice improvement.

Braking - Braking seems fine. Don't see any noticeable degradation in braking performance especially panic stops. It does what I expect it to.

Handling - Definitely not worse. That is one of the main reason why I keep them higher than stock. Higher PSI stiffens both inner/outer sidewalls up so there is more lateral support especially in the initial turn-in and it seems to glide more effortlessly. At 34 PSI tires feel squishy and the intial turn-in has roll, which is reduced greatly at 43 PSI. For me, it is more confidence inspiring. The steering also feels a lot more tighter/responsive at the initial turn-in.

Wear - Hypothetically, yes the wear might be higher in the middle than on the sidewalls at higher tire pressure. I am not concerned about that since the car came with these tires and they have about 60% tread left. Most of the time, I have a lot of weight in the car. (2 kids in the back, 2 baby seats, 1 big stroller and 2 adults in the front) so running high PSI makes the car drive effortlessly while at 34 - 35 PSI, the squishy tires don't seem to handle the weight well and everything is labored. In any case, I will be replacing them with different ones in the next 2 years or so anyway.

I would add ride quality/harshness as well. Ride quality doe become a bit more rough/harsh at 43 PSI or so over the occasional rough pavement, but generally it is fine for most of the roads I drive on, which are nicely paved.

 

Look at running a wider wheel/tire package......8.5''-9'' width w/ a 20mm offset w/a 255-55x18 or a 265-50x18....That'll add some thread width, which will increase the scrub radius, which will give a little more steering feel. I'd be great if you could increase the caster thou.....One thing IDL 'bout the gen3's......

 

Update from OP - I took my car into Toyota dealership to have them look it over. Diagnosis was a loose drivers side inner tie-rod. Service advisor indicated that this cannot be seen or felt from underneath my shaking either wheel with hands to feel for play. Does this seem accurate? Both as a correct diagnosis and also the fact that this is the problem yet it cannot be demonstrated? Another thing Toyota mentioned is because of the steering rack style, the inner rod cannot be replaced like a traditional hydraulic rack. The entire rack will need replaced. I don't have much confidence in that statement either. I have an appointment in a few days to have Lexus look it over as well.

 

I recently had a diagnosis of a loose inner tie-rod on 10' RX350 with 120k miles and was told the entire rack needs replaced. Any ideas for how to verify this at home?

 

I would find a well-respected Toyota-knowledgeable independent repair shop if you are planning to pay someone else to do this job for you.

 

BECK/ARNLEY 1017867 - Inner Tie Rod End, '08 - '16 Highlander may fit the RX. However the RX rack is a different part number than the Highlander.
The measurements are 16mm both ends and 1.5mm is the thread pitch. A review at Amazon said it fit their 2014 Highlander. If it fits this is a lot cheaper than a new rack! $23!
https://www.summitracing.com/parts/b...7/applications

 

Apologies on double reply, it looks like an admin may have consolidated two threads. Thank you for doing so

 

This video may possibly give you an idea of what to do to at home to verify a loose inner tie rod - Also his solution to the issue may be something you can try as well.

 

There is a simple test ... set your steering straight [then do not mess with it till the clamps are brought back] and release the clamp on the bellows on either side of the rack. If oil drips out from either side then you need to replace the rack. Re-position each of the bellows [no compression or extension and no twists] and bring back the clamps. This leak can also be predicted if you keep loosing the steering pump fluid regularly without a trace on the ground or engine. This is also referred to as leaking seals. If that happens it is best to replace the rack. If this is your problem and you want to do a DIY I can give you some pointers.

There are more intricate reasons for a failure, but they are very rare. Slop in the tie-rod ends and even slop in the rack mounting happen most of the time.

Salim

 

Mr wizard id showing the check I mentioned on a LS.

Salim

 

The RX has electronic power steering, thus there is no pump or hydraulic fluid to leak.
This brings me to ask how valid is it to compare the test for a vehicle with a power steering pump to one with electronic power steering and no pump as it should not have any fluid to leak. I suppose it has grease inside the rack.

 

hello mate,
a friend of mine that isn't much internet savy, asked me to help him order a Rack and Pinion for his Lexus RX350 from 2013.
I signed up to the forum and while looking, i came across this reply.

this msg from your reply: "The RX has electronic power steering, thus there is no pump or hydraulic fluid to leak." Does this mean that the rack and pinion I am looking for, for his 2013 RX350, needs to be electronic, without the tubing etc. etc., correct?
I just want to make sure, before I buy it.

I quoted this person, but if anyone else can answer me, it'd be highly appreciated.

thanks a lot

So this means when I look up for the rack and pinion