Wet Speed Sensor and what it means to me?

[fred_dot_u]

This just in, photo taken Christmas Eve 2023. Despite my physical infirmities, I was pleased to discover how easily this component was removed and examined. I had no banana for scale, but I suspect that aspect is unimportant.

Not so pleasant is the discovery of moisture/coolant on the body. This explains the gradual depletion of the G48 coolant in the reservoir.

Based on my research here and elsewhere, it's likely related to the turbine-like whine heard from the motor when applying power at any speed, rather than the noise maker for pedestrians heard at slower rates of travel.

This particular photo resembles rather precisely the others I've discovered on the forum and internet resources, but not quite as bad as the severely rust-encrusted versions.

The question at hand is this:

For how many miles can I expect to use this vehicle without performing any service or repair? As a corollary, in what form will impending doom appear? Will the motor seize up and lock the wheels or will it begin to sound like a Cuisinart™ far enough in advance to get it home safely?

I ask this because our fleet of two 2013 Rav4EVs, each with a tad more than forty thousand miles / sixty-four thousand kilometers will by necessity become a fleet of one in six months time. My wife will no longer need to use this vehicle and the plan was to sell it. The amended plan is to drive it as long as possible, ideally up to the six month break point. The last twelve months of this heavier-used vehicle encompassed 3200 miles / 5100 kilometers. One can extrapolate that we therefore require half that for the next six months as the use is consistent and uniform.

It is realistic to expect that the motor will continue to (figuratively) grind away for that long? Is it time or distance or both? Velocity equals time multiplied by distance, but I don't think that formula applies here.

I'm self-(un)employed and can schedule clients around vehicular emergencies as needed, which means that a system failure during my wife's trip to or from work is of minimal impact, other than to marital harmony. You should have seen the smoke from her ears when her 2002 Rav4EV gave up the turtle and stranded her on the side of the road. I've convinced her that she won't be left in the dust this time around, but I'd prefer to have the communal backing on that possible-bluff. If the worst happens, I become chauffeur service up to the six month calendar break. That would double the two thousand mile / three thousand kilometer tally on my vehicle for at least half a year, but we'd still be saving on motor vehicle insurance and a partial registration rebate.

As you can see from the above diatribe, we have decided that the expense of a motor rebuild can't be justified in relation to the desired future use. I'm not sure where to ship a Florida based Rav4EV for such a repair, but the round trip expenses for shipping alone disqualifies the concept.

 

[asavage]

Inverter failure from moisture ingress (migrating from the motor side, where the sensor you removed lives, to the other end, where the power electronics live) is when the repair becomes both extremely expensive and leaves your wife stranded.

If you address the issue before that, it's a lot cheaper to fix. If you've noticed a reduced G48 coolant level in the reservoir, your time is short; it doesn't take very much coolant leaking on the motor end before there's a pool of it on the inverter end, then "poof".

 

[fred_dot_u]

The east coast of the US is lacking in out-of-warranty service facilities for our type of vehicle. There's an independent Tesla service operation about 75 miles away, but he's expressed lack of interest to assist. The expense of shipping this vehicle to a qualified center, round trip, plus the cost of the repair begins to be a substantial loss, unlikely to be recovered by selling the vehicle at the six month mark. This is an opinion, however and if there are corrections to be applied, I'm receptive.

 

[asavage]

The same lack-of-qualified-service problem afflicts pretty much all used EV owners everywhere in the US (unless you're in the SW and are willing to deal with Tony). Everyone from Volt owners to Tesla owners have the same issue: having to use the very expensive dealer network (if your EV isn't an orphan) or begging someone who might be willing to work on your EV to take a shot at it.

This situation should resolve reasonably quickly over the next few years, just as the public charging infrastructure will grow to fill the void -- this type of situation is where Capitalism shines -- but right now, yeah, we're the early adopters with arrows in our backs, and we have to find our own solutions.

I've got a local shop that's willing to perform a battery drop/lift for me, so when I get 'round to having to/wanting to do that, I can. But won't it be nice when we can (somewhat) reliably hire this out?

---

Just before I bought my RAV4 EV in 2017, I was searching for a shop to replace the engine in my AWD Aerostar; everything worked but was very long in the tooth, I liked the van and was willing to spend to keep it in the family. In the end, I couldn't get anyone to take on installing a rebuilt long block, and instead I bought an AWD Sienna instead, and sold the Aero (the last of five I'd owned over the years) to an enthusiast in Oregon. The problem isn't only with EV owners: sometimes you just cannot trade dollars for qualified labor, and as we Boomers age out of the workforce, this is only going to get worse.

 

[JDP]

Here’s my speed sensor at about 22k miles on a reman with a sticker of 2020/04/27.

I touched the droplets to a white paper towel and I think it was blue before it spread too thin to make out any color.

Haven’t noticed any change in my reservoir fluid level. Yet…

View attachment IMG_4324.jpeg

View attachment IMG_4326.jpeg

 

[asavage]

Three tablespoons of coolant wont hardly show on the reservoir level, but can wipe out half the grease in the outer rotor bearing on its way to the stator cavity (and further).

It's a lot cheaper to not have coolant on the inverter side. Once it wicks up the wiring harness on the inverter side, it gets expensive; Tesla sells no parts, everything has to be salvaged from another LDU or fabricated.

When I had coolant on my LDU's speed sensor a couple of months ago, I stopped driving it immediately, pulled it out and remove the rotor within a month and found coolant and corrosion was limited to only the rotor and stator cavity, meaning that I didn't have to split the gearcase, I didn't have to touch the inverter, and it was a lot less work to get it back in running condition than if I'd waited longer.

I was lucky, but I also didn't push my luck.

 

[Jonathan_UK]

I checked my speed sensor today, and it was wet with moisture but showed no signs of coolant. However, as there is a helicopter blade whirring sound coming from the motor at low speeds (10-20 mph), I assume one of the bearings has gone, and an LDU refurb will be needed soon.

The motor was already a remanufactured version fitted in August 2018.

In addition to the QCC coolant delete, I've ordered an SKF bearing and am considering a full refurb kit (https://evshop.eu/en/accessories/1352-large-drive-unit-repair-kit.html). As this kit is quite expensive, I am hoping there might be a cheaper option, such as just replacing one bearing and seal. Does anybody know of a similar kit available for purchase?

 

[ce2078]

Condensation means coolant is past the first bearing and water is evaporating out of the coolant. I.e. water by the stator.

If you want to DIY it, pull it apart and check the bearings and gears. We can sell you individual parts if you can't find them. At a minimum you need the seal (or bypass) and 1 bearing.

 

[asavage]

If you're doing a coolant delete (dry rotor conversion), you don't need the rotor seal. I replaced both rotor bearings when I pulled my rotor (mine is a reman in 2018 as well) but only the outer one was really in need. My special LDU disasssembly tools thread.

If you want genuine -- not counterfeit -- rotor bearing(s), I can recommend Acorn Industrial in the UK @USD$114 ea. I got them to amend their checkout so you can specify "no VAT", and they ship fast. There are lots of counterfeit SKF bearings being sold.

Be careful to not damage any molded o-ring-type seals you may encounter, as AFAIK there are still no available replacements. They're robust, but still . . . be careful.

If you have a vented reluctor chamber, it's possible to have water ingress on the inverter side via the HV cable glands, and that water can condense over on the speed sensor, which is rarer than a rotor seal leak, but also means that you must pull off the inverter cover and inspect for water there; that's a good idea anyway, if you've got the LDU out, and it's not a whole lot of add'l work. We're seeing more leaking HV cable glands now, mostly in areas that use snow-melt accelerators ("salt"), which corrodes the glands -- which can only be purchased as part of new HV cables -- expensive (~$600 ea). Perhaps someone is mfgring replacement glands by now.