Vadim

Martin, thanks for the video. I would also recommend to remove the passenger’s ceiling handle (just two metal clips there). Having two pretty assistants as on the video definitely helps )

Wiki for Active Stabiliser System: https://en.m.wikipedia.org/wiki/Active_Stabilizer_Suspension_System The article suggests that such systems were only tried on RX450h 2010. So, if you have it, it can also add to noises in suspension )

Herbie, indeed, it is a separate system, called “Active Stabiliser System”. It was installed, probably, as an option on some top spec RX mk3. It comes at front and rear stabilisers as a set, so the easiest way to check is to look under the rear bumper. My SE-L 2011 has standard stabiliser bars without the motors. Rear stabiliser bar:

1. If it is just a light knocking noise from the shock absorbers, it can be harmless (there are reports of knocking valves from new, but that did not affect the longevity of the struts). 2. Swapping from air to coil suspension is possible, but too expensive (besides the struts you’ll have to replace rear wishbones which hold the springs, as they differ for spring and air suspension). But the biggest trouble is to make the computer happy when you switch off the air pump. Note that an error in air suspension system turns off some other systems like traction control. After all parts and labour are considered, you may find it more convenient to keep air suspension. 3. Make a thorough diagnostics to identify the source of the noise. It can be shocks, top mount, top mount nuts, stabiliser links, steering rods, engine mounts, ball joints etc.etc. Mind that RX also has a motor on the stabiliser bar, which prevents body rolling (photo below) and can also cause noise. When you know what causes noise exactly, it may appear a much smaller job to fix, or you can decide to live with it. Also I would not take the level of diagnostics expertise of lexus dealership for granted - it still depends on the skill of the mechanic who do the job and can be better or worse than that of a no-name garage nearby. Motor on front stabiliser bar:

+1

You don’t need to remove the engine - it is just necessary to lift it a few centimetres and support it while the engine mounts are removed to give access to wishbone fixing one side at a time.

Refreshing lug nuts: Mitsubishi uses exactly the same lug nuts on Outlander, Shogun and some other models. Due to relative unpopularity of Mitsubishi brand their original lug nuts can be sourced at a significant discount.

Toyota/Lexus has its own specific centre bore size (60.1mm) which is critical for correct wheel positioning on wheel hubs. For this reason those who look for alternative wheel rim options have to stay within Lexus/Toyota domain even when the rest of the wheel rim dimensions appear similar.

For those who have been thinking of a spare set if wheels for winter, or a 18” wheel rims, here is an example. Wheel rims: 7.5Jx18 ET35 (from Lexus NX) Tyres: Continental CrossContact LX 255 60 R18 18” tyres are noticeably softer on ever degrading London roads, and wider tyre profile (255 vs 225mm) protects sensitive diamond-cut wheel rims from curbing. This size of tyres is standard for Nissan Navara, Range Rover Discovery, VW Amarok, Jaguar F-Pace etc., and often can be sourced as a set in near-new condition for a fraction of original price.

If you care about winter driving, best get a set of winter tyres (not necessarily new ones). Driving on snow and ice with summer tyres is not safe even if the tyres are new and it is just one snowy day a season.

Has the navigation experience improved after the update? I’ve got an impression that the RX Mk3 navi system is so old, that the map update may not be worthwhile.

Cracked front wishbone bushes, which pass MOT with no advisories:

Lexus suggests that front wishbones for RX can only be replaced as a whole unit and are not serviceable. However similar wishbone for Toyota Highlander is serviceable and has the “tablet” rubber bush as spare (see below). This bush should fit RX mk3 and can be installed using an appropriate hydraulic press. Unfortunately, there is no Toyota replacement for the “candy” bush, and only aftermarket options are available. The longevity of the aftermarket “candy” would depend a lot on the amount and quality of grease you add when replacing it. Another - and often a better option - is to buy a used part in good condition. For air suspension cars, used wishbones are very difficult to find, but the fixing points of the height sensors can be re-welded on the replacement wishbones. Rubber bush for Toyota Highlander / RX III: Toyota part No:48655-08030 Dimensions: 58mm diameter, 62mm height, hole size 14mm Bought the bushes to replace the cracked ones in my 2011 RX, but haven’t managed to do it yet - the car drives well and passes MOT with no advisories.

Don’t even bother with aftermarket - there are multiple reports of rubber bushes falling apart in under 10k even for some reputable aftermarket brand names. In RX front wishbones are relatively difficult - read expensive - to replace because you have to remove the engine mounts, so there is a considerable risk of expensive second replacement if the aftermarket part does not perform. If new Toyota parts are expensive I would recommend buying used ones in good condition.

Yes

I came across a top mount for Toyota Avensis T23, which might be used as a temporary substitute for the RX450h top mount: see photos below comparing the original top mount with the alternative. It appears to have the same position of bolts, the same bearing and enough space for the air hose connector. It has smaller diameter and slightly shorter bolts. Note that installing Avensis top mount on RX would be a material change in the construction of the car, which might invalidate warranty, so it will be all at your own risk. Still, in my view it would still be safer than running on the original top mount with disintegrated bearing, until you get a proper replacement.

I replaced the bearing in one of the top mounts with Brian from Orchard Engineering two years ago, and it has been running fine since then. The top mount can be removed from the strut (it has a cash cowing element to it, when Lexus suggests that it must be replaced with the whole strut assembly). The removal procedure is not any different from other cars: remove the plastic cover, remove rubber cover, unwind the air pipe (make sure the car is supported by a stand, so that it does not drop down when you remove the air pipe, also ensure that the wheel is supported in lower position, so that it does not drop when you unwind the top mount nuts), then undo the 3 nuts holding the top mount. To remove the central nut, which holds the bearing on the strut axle, you'll need an impact driver with long bit. Sometimes when the top mount is easy to detach from the strut axle, you can just push the strut down (it has no air pressure by that time, so you just need to overcome the internal gas resistance), and remove the top mount without removing the shock absorber itself. While removing the top mount without removing the strut, make sure you don't push the strut too low, because it can strain the wishbone rubber bushes too much with a risk of the rubber cracking (particularly for 8+ years old car). If the top mount has ceased on the shock's axle, it is better to remove the whole strut by unwinding the stabiliser link and two 22mm bolts at the bottom. This is a standard procedure any qualified mechanic can do having proper tools on hands.

I doubt that, as the motor and mechanics are rarely the issue. The problem comes from the PBD circuit board.

Keeping the battery charged definitely helps, but in my case the PBD did not work even after battery replacement. Then it suddenly started working again after two months. The PBD circuit board shows no signs of any batteries or supercapacitors, which could be used for memory keeping and would be subject to battery voltage issues. So the only thing to blame appears to be the ageing chips or other elements of the PBD. Unfortunately, this module is so specific, that no ECU specialists can diagnose it, let alone repair.

The bearing is "6302RS"

One of the reasons for the top mount bearing failure (if it was your case), is that the top mount is covered almost hermetically by a rubber boot from the top. When you pressure-wash the wheel arches, water squeezes between the top mount and the car body, and stays inside the boot. After some time the water gets inside the bearing covers, and rust starts to eat the bearing balls and guides.

The troublesome part in air struts is the top mount, which is not sold separately by the dealer. Fortunately, Brian Herridge from Orchard Engineering can replace the worn/disintegrated bearing in the top mount by post (used to be £75 including return postage). Recently he teamed up with a nearby garage to provide drive-in same day replacement, which is much more efficient than what Lexus dealers offer. Beside that, the air struts seem to be quite long lasting (my car has original strut at one side with 192k miles, but I had to repair the top mount). Other parts which can bring some headache are height sensors at every wheel, and the air compressor (expensive parts, but I'm not sure how often they break). Another material consideration, is that the pneumatic suspension on RX450h is stiffer than the sprung suspension (more sporty?), and the rear shocks have smaller travel for compression (see my post about it). Good news is that shorter travel means longer life for rear control arm bushes.

I would not be overly optimistic about dealer's service history: outside of the warranty period many repairs become optional (like noise in the steering mechanism, suspension etc), and owners often postpone them in anticipation of selling the car and partly because of thrill of the dealer's repair price tags. So it is perfectly possible to get a FHS car with a range of very expensive pending repairs. Nothing replaces a good on-site check of the car by a qualified mechanic.

Unfortunately, there are no traces of batteries or capacitors for memory keeping, which could explain the PBD failure in ageing or long underpowered units.

A few photos of the troubled PBD ECU for reference.