EV motor maintenance? Gear fluid change? When?

[Jseis]

All the published specs show it at 9.61:1. But I'm not sure I follow you on the heat thing. What does engine heat have to do with axle gear temperature? I would venture to say that the electric motor gear oil will get hotter than the differential on an ICE because the case is also housing the motor, whereas on an ICE truck the differential is separate, and it catches a lot of airflow.

I think we agree..,modern ICE AWD cars efficiency is tied to effective combustion and heat management critical with higher compression/operating temperatures/exhaust temps and engine/transaxles units means more nearby heat sinks, thus heat damaged gear oils.

BEV motor-transaxle units don’t generate anywhere near the heat that BEVs do, thus their transaxle gear oils have a ”cooler” environment. I’m not saying they don’t generate heat, but nothing like a BEV.

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[Piquette]

BEV motor-transaxle units don’t generate anywhere near the heat that BEVs do, thus their transaxle gear oils have a ”cooler” environment. I’m not saying they don’t generate heat, but nothing like a BEV.

I’m sorry, you lost me there. Do you mean BEV motor- Transaxle units don’t generate anywhere near the heat that “ICEs” do?

 

[WXman]

I think we agree..,modern ICE AWD cars efficiency is tied to effective combustion and heat management critical with higher compression/operating temperatures/exhaust temps and engine/transaxles units means more nearby heat sinks, thus heat damaged gear oils.

BEV motor-transaxle units don’t generate anywhere near the heat that BEVs do, thus their transaxle gear oils have a ”cooler” environment. I’m not saying they don’t generate heat, but nothing like a BEV.

I’m sorry, you lost me there. Do you mean BEV motor- Transaxle units don’t generate anywhere near the heat that “ICEs” do?

Yeah I'm kind of lost too. Lol.

So, what I'm talking about is an ICE F-150 vs. an EV F-150. Or any ICE truck really.

If you look at how they are designed on an ICE truck, the differential (and therefore gear oil) is in a totally separate housing. The rear gear oil is nowhere near any other sources of heat, except maybe the exhaust tailpipe which is 18" to 24" away. The front gear oil is in a totally separate housing from the engine with a large air envelope between them. AND, in addition to all this both of those differentials are getting airflow directly over them while driving because they hang low and exposed.

By contrast on the EV F-150 the motor and gearbox are one. AND they are surrounded by skid plating and shields so that little to no airflow is passing over them. This is true front and rear. So, the heat generated by the electricity coming into them and friction is going to cause them to heat up quite a bit.

So I surmise that maybe on an EV truck like the Lightning, it will be MORE important to keep the gear oil changed on a regular basis. These automakers spec really long fluid change intervals for marketing purposes. It creates a perceived lower cost of ownership. Also, they get EPA kick-backs when they spec longer change intervals. But, the truth is that changing fluids and oils far more often than the manual calls for will almost always lead to better longevity of vehicles.

 

[Athrun88]

So I surmise that maybe on an EV truck like the Lightning, it will be MORE important to keep the gear oil changed on a regular basis. These automakers spec really long fluid change intervals for marketing purposes. It creates a perceived lower cost of ownership. Also, they get EPA kick-backs when they spec longer change intervals. But, the truth is that changing fluids and oils far more often than the manual calls for will almost always lead to better longevity of vehicles.

I generally have the same philosophy; I'd rather spend a few extra bucks to ensure my consumables are fresh/well maintained than have to replace the full unit or module. On all my previous ICE vehicles, I did full synthetic oil/filter changes around every 10,000km (6,200mi), tires every 80-100,000km (50-62,000mi) and transmission/diff fluid changes and brake pads/rotors every 100,000km (62,000mi). Sure the manual says longer, but is there any actual harm in changing fluids sooner/more often other than me spending more money?

Things hold even more true for me now that I have an EV. Near ZERO cost in maintenance, other than washer fluid, tire rotations, etc... will only encourage me to change out any luberication fluids in the truck sooner than what the manual calls for. Lots of people see the "Don't change for 100,000km" marketing but they fail to see the tiny "Up to" in 2pt font size before the 100,000 number. Also, I personally believe that most of these intervals are determined in a lab or simulated use and does not 100% accurately reflect what could/would happen in the real world such as unexpected contaminant intrusion or premature internal component wear.

 

[Athrun88]

The only harm is to your wallet.

... other than me spending more money?

Other than that . Gotta pay to play.

 

[bmwhitetx]

I love all the non-engineers on here second guessing the manufacturer and their engineering teams.

Manufacturers have always leaned toward a conservative approach in maintenance requiring service sooner rather than later. If Ford says 150K then that’s good enough for me.

My son does cooling systems engineering at a major vehicle manufacturer. The amount of testing, measuring, etc they do now is incredible. When I ask him if he considered “x”, he rolls his eyes and starts talking Greek to me.

 

[Heliian]

To my eyes it looks like regular oil filte

It is a spin on type filter, the internals will be different whether it's engine oil, fuel, Hydraulic or coolant. Some spin ons are in the suction line, some pressure.

I'd rather spend a few extra bucks to ensure my consumables are fresh/well maintained than have to replace the full unit or module

The only harm is to your wallet.

One of the main reasons most automatic transmissions don't have a filter replacement is that opening the system created more problems than keeping it sealed. Modern oils don't need to be replaced as frequently.

 

[Athrun88]

I love all the non-engineers on here second guessing the manufacturer and their engineering teams.

Manufacturers have always leaned toward a conservative approach in maintenance requiring service sooner rather than later. If Ford says 150K then that’s good enough for me.

My son does cooling systems engineering at a major vehicle manufacturer. The amount of testing, measuring, etc they do now is incredible. When I ask him if he considered “x”, he rolls his eyes and starts talking Greek to me.

So what you're saying is that there isn't any harm since what I personally do as a 'non-engineer' is even more conservative than the manufacturer. What is the harm in swapping something out before it completely wears out? That's like saying you don't have to replace tires until you hit the wear bars, don't change the oil until the oil light turns on, or brakes until they squeal. I agree and I have 100% confidence that manufacturers have built in margins and such with millions of dollars in R&D/testing and employ people who are infinitely smarter than I am; however, it still doesn't discourage me from doing more maintenance than is called for as long as I am aware of the added overall cost in doing so.

One of the main reasons most automatic transmissions don't have a filter replacement is that opening the system created more problems than keeping it sealed. Modern oils don't need to be replaced as frequently.

I agree they don't need to be replaced as frequently but even modern automatic transmissions have ports and openings to facilitate the replacement of the fluid inside or inspections. I don't do those changes myself and would take it to a shop. As there are ports built in for the purpose of draining and filling fluids, I don't see how it creates more problems if it's been engineered/designed for it.

 

[WXman]

Typical ice runs @ 200°f. The electric motors don't come close to that much heat. I don't have the actual spec handy. I'll look it up when I get home.

A differential in an ICE truck runs at 200 degrees?

The only harm is to your wallet.

But if it reduces repairs, one could argue that it helps the wallet...in the long run.

I love all the non-engineers on here second guessing the manufacturer and their engineering teams.

Manufacturers have always leaned toward a conservative approach in maintenance requiring service sooner rather than later. If Ford says 150K then that’s good enough for me.

If you believe that, I have some ocean front property in Kansas that I'll sell you.

Truth is it's exactly the opposite. These OE's spec fluids that save THEM money. For example, 0W20 oils ONLY happened because it saves them money on EPA certification, not because it's what extends the life of an engine. They spec longer intervals because the EPA rewards them for it. They couldn't care less if your vehicle lasts 500,000 miles. They just want to get through warranty period, and then they hope you buy another.

 

[bmwhitetx]

Well there’s the whole sealed system thing. You and @RLXXI I would probably trust. I think an amateur DIY’er could do more harm than good.

 

[21st Century Truck]

A non-engineer here whose Mach E front motor did fail, catastrophically (see post #4 here) and whose next, warrantied front motor was about to fail when I traded the car... as well as the youngest brother of three, the others both engineers who never, ever let me forget it

IMHO this is a question of relative risk. Yes, OEM testing parameters establish reasonable intervals for X, Y and for Z. Yes, IMHO there is no harm in changing oils etc. earlier as long as it is done carefully, with good workmanship and to standards, which is BTW why many of us prefer to DIY these things, as we are sure to do it right and not depend on the unseen back-of-shop 20 year old who might be working to time and not to standards of carefulness, and who might be thinking of his date tonight rather than about the potential to mis-thread something. I once was that 20-year old... just sayin'.

Anyone ever watch thru the open bay doors as the wheel / tire guy grabs that pneumatic tool and goes UGGA - DUGGA on the wheel lugs, instead of even thinking about how to set a torque wrench to a manufacturer's torque setting?

On the other hand, these EV motors on our Lightnings are not easy to get to for example the motor refilling plug up on the side.

My Mach E's front motors were made by Borg - Warner, a company with a long history of good manufacturing. Yet, they both failed, both within warranty... and the 1st failure was absolutely a failure of its internal seals. Cause = unknown to me, of course, so it could have been heat effect, or it could have perhaps been the effect of my installation of German high-end coilover sets which might (??) have slightly changed the half-axle entrance angle within the motors long enough to...??

I write this because, with 76,000 miles on our Lightning now I am weighing having their Mercon fluid (and any filter) changed in both motors. Cost vs. inconvenience vs. relative risk, right?

A key point I learned with the Mach E front motor failure(s): once a motor is changed out under Ford warranty, this particular new assembly's warranty then runs for only the next 12 months, no matter the age of the car or its mileage or its original warranty for the rest of the car. And the warranty cost the dealership charged Ford Corporate for the new motor and labor was a shade over $5,000 (I saw the warranty bill to Ford Corporate... I'm at a good dealership and they work with me).

 

[Athrun88]

Just for the record, as a non-engineer-trades-trained-DIYer, if something is a sealed system, I am just smart enough to not mess with it. To me, sealed = replace the whole thing; however, if there are ports, inlet, outlet, discharge functions, I will explore the DIY route because it was designed for it. I never think of myself as smarter than the actual engineers who designed these things. I am, and I'm sure most of us here, are also smart enough to determine what should/could be DIYed and what should/must be left to the shop for liability purposes

 

[Karlos]

Would be interesting to see a filter cut open & pleats inspected for particulate matter, fluid condition etc. Would make an informed decision easier for the next maintenance interval.

 

[WXman]

Internal Combustion Engine runs at 200. Differential maintenance is 100,000 miles for most.

It's the engine heat that does the premature breakdown of fluids. The electric motor does NOT get any where close to an ICEngine temperature.

I think we've got two totally different tracks running trains of thought in this thread.

How did engines ever get brought into this discussion? OP was talking about GEAR OIL. So then the conversation turned to maintenance intervals for ICE GEAR OIL vs. EV GEAR OIL. I don't know how engines came into the discussion.

So again, engine heat has little to nothing to do with gear oil temperature on an ICE truck. And therefore the gear oil should stay much cooler than the gear oil on an EV, and therefore the idea (which was presented earlier in this thread) that EV gear oil should last longer than ICE gear oil is probably wrong. It's likely just the opposite.

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