Have your service center check large rear drive unit for coolant leakage before warranty expires

[Droschke]

As far as I know, pretty much all LDUs put into cars anymore are remanufactured (I've heard rumors they quit making them, but can't confirm). All of the drive units since ~2015 use the same inferior single lip seal that is more likely to wear out prematurely. I've pulled apart a few LDUs that are less than 2 years old with serial numbers past 1M. Those ones have the newer style differential (6 spider gears instead of 4), but still use the same s**tty single lip seal. By the way, the revision letters end at Q, even though there are definitely some small changes in the motors made since 2017 (like the diffs), why they haven't kept track with further revision letters, I don't know...

If you've really only done 10k mi in 5 years, you should definitely check your speed sensor for signs of coolant... I've noticed that cars that don't get driven much tend to be more likely to have early failures than cars that get drive more often. Can't necessarily say that that is always 100% true, but it's a trend that I have noticed...

Thanks for the info. Here is what's on my 2017 work order:

ASY,P-TRAIN,MECH,COMPLETE,RC (1002633-00-Q) Quantity 1
ASY,HV COVER,INVERTER (1003783-00-B) Quantity 1
BRKT, HV CBL TO DRV INV, 2MM THK, STL (1019545-00-A) Quantity 1
SCR,M6-1.0X12,PH,TORX,STL,SEMS,PATCH (1011427-00-B) Quantity 1

Is that any useful?

 

[Droschke]

I’d strongly suspect not given they aren’t used in any new cars any more. Reman from here on out…

So, it appears that Tesla remanufactures the LDU with the same problematic single lip seal and passes the problem to the next car. I wonder why they don't resolve this weak seal issue. One expects they should be knowing about their own design and make corrections by putting in better components. Better seals shouldn't be that expensive.

 

[howardc64]

So, it appears that Tesla remanufactures the LDU with the same problematic single lip seal and passes the problem to the next car. I wonder why they don't resolve this weak seal issue. One expects they should be knowing about their own design and make corrections by putting in better components. Better seals shouldn't be that expensive.

For a Silicon Valley company seeking valuation. They've moved on and we're stuck with all the poor designs and poor endpoint service protocol. Since you are not DIY (from prior post) I'd pay annual diag fee to pull the speed sensor and check. With a 15, you've got 4-16mo remaining on DU warranty

 

[ucmndd]

Maybe I missed it in this thread or another, but has anyone convinced Tesla to actually replace a DU under the 8 year warranty based on the presence of coolant on the speed sensor?

If the car was otherwise operating fine for the moment and not throwing errors, I could see them saying "lol yeah that's within spec" and sending you on your way.

 

[Droschke]

For a Silicon Valley company seeking valuation. They've moved on and we're stuck with all the poor designs and poor endpoint service protocol. Since you are not DIY (from prior post) I'd pay annual diag fee to pull the speed sensor and check. With a 15, you've got 4-16mo remaining on DU warranty

Agree. Not a DIY owner. But even with a proactive inspection done by Tesla, the problem seems not to disappear after my warranty expires at the end of Feb. 2023. A 3rd party fix like what the QC Charge offers seems to be the solution.

 

[Droschke]

If the car was otherwise operating fine for the moment and not throwing errors, I could see them saying "lol yeah that's within spec" and sending you on your way.

I think that's the modus operandi.

 

[ajbessinger]

So, it appears that Tesla remanufactures the LDU with the same problematic single lip seal and passes the problem to the next car. I wonder why they don't resolve this weak seal issue. One expects they should be knowing about their own design and make corrections by putting in better components. Better seals shouldn't be that expensive.

There's not much they can do apart from use a higher quality seal. Even doing that though, problems are still inevitable at some point down the road as the seals are, and always will be a wear item (which is why we also install a drain kit when we rebuild them). They obviously didn't intentionally design it with this flaw, I think they were just shortsighted in thinking the seals would last a lot longer, and clearly learned from their mistakes on all subsequent drive unit designs (why they haven't gone back to the more robust triple lip seal though, I have no clue).
There's really no "permanent" fix for these drive units short of essentially a complete redesign, or someone figuring out a way to put an SDU in instead (which would certainly limit the power for most models).

 

[ajbessinger]

Maybe I missed it in this thread or another, but has anyone convinced Tesla to actually replace a DU under the 8 year warranty based on the presence of coolant on the speed sensor?

If the car was otherwise operating fine for the moment and not throwing errors, I could see them saying "lol yeah that's within spec" and sending you on your way.

I haven't heard of anyone getting a replacement that way personally. I think they do typically require there to be codes present, extremely noisy, a "seizing" motor, or an outright total failure to qualify for replacement under warranty. However, checking the speed sensor does a few things for you:
a) knowledge that a problem is imminent (maybe don't take the car on any long trips)
b) evidence that you might be able to use in your favor if you brought up the issue while the car was still under warranty, but then the motor fails out of warranty
c) if enough people do it and bring it up in a S.C. setting maybe Tesla could "wake up" and realize that large numbers of people are figuring out how major of an issue this is (unlikely, but potentially possible).

I do know that on the Mercedes B-Class (which also uses an LDU), Mercedes Dealers will check the speed sensor and cover a replacement under warranty if coolant is present. So it's clearly known that this is a real problem, I think that there are just SOOO MANY Model Ss out there with LDUs that Tesla chooses to ignore the issue and focus on production/deliveries instead of the existing cars.

 

[Droschke]

There's really no "permanent" fix for these drive units short of essentially a complete redesign, or someone figuring out a way to put an SDU in instead (which would certainly limit the power for most models).

If a customer doesn't care about the reduction of power and opts for an SDU, can your shop do it?

 

[Asummers]

Maybe I missed it in this thread or another, but has anyone convinced Tesla to actually replace a DU under the 8 year warranty based on the presence of coolant on the speed sensor?

If the car was otherwise operating fine for the moment and not throwing errors, I could see them saying "lol yeah that's within spec" and sending you on your way.

Yes this is exactly what they did for me. I had no signs of a problem. I was just running out of time. My SC was very cooperative. Did not charge me a diagnostic fee. Maybe they would have if it had not been leaking.

 

[ucmndd]

If a customer doesn't care about the reduction of power and opts for an SDU, can your shop do it?

I'm guessing that would require some significant hacking as there's no from-the-factory config for a RWD SDU car.

Might be feasible to downgrade a PXXD car in the manner you describe (say turning a P85D into just an 85D) but even that would seem to require a fair amount of software tinkering.

 

[ucmndd]

Yes this is exactly what they did for me. I had no signs of a problem. I was just running out of time. My SC was very cooperative. Did not charge me a diagnostic fee. Maybe they would have if it had not been leaking.

Good to know, thanks. Would you be willing to share a copy of your invoice for this work? Might help some of us down the road with less cooperative service centers.

 

[airborne spoon]

I haven't heard of anyone getting a replacement that way personally. I think they do typically require there to be codes present, extremely noisy, a "seizing" motor, or an outright total failure to qualify for replacement under warranty. However, checking the speed sensor does a few things for you:

if there is some moisture in there after pulling/inspecting the speed sensor but there is no errors... if some extra coolant were to find its way into there somehow it might start popping some errors lol just pour like a cup of coolant in the hole. not that I'd advocate for purposely tampering with the motor and creating a false warranty claim

 

[howardc64]

Scheduled SC visit with the app and got a $420 diag fee estimate before I can even talk with the SC mgr that has denied problem every year since 17 installation. Got this info < 24 hr before appointment so app cancellation will probably auto charge me $100 for a couple of chats. FYI on out of warranty attempt to engage Tesla on this. I would have brought in the car with DU belly pan fully removed for a quick access to the speed sensor.

This is likely my last engagement with SC. Just about all of the Roadster owners seems to be with independents now.

 

[beatle]

Since the process of checking is so simple, why not go to a good independent shop to pull the panel off and take a look at the sensor? My car is due for its annual state safety inspection in December and my battery/DU warranty is up in March, so I plan to have my local garage perform the check while they have the car on the lift already. I'm sure it'll be a lot less than $420. If they find something I'll schedule a follow up appointment with the SC.

 

[Droschke]

I plan to have my local garage perform the check while they have the car on the lift already. I'm sure it'll be a lot less than $420. If they find something I'll schedule a follow up appointment with the SC.

Wouldn’t you end up paying Tesla that $420 diag fee estimate anyway?

 

[howardc64]

Since the process of checking is so simple, why not go to a good independent shop to pull the panel off and take a look at the sensor? My car is due for its annual state safety inspection in December and my battery/DU warranty is up in March, so I plan to have my local garage perform the check while they have the car on the lift already. I'm sure it'll be a lot less than $420. If they find something I'll schedule a follow up appointment with the SC.

Already pulled the sensor and checked on post #35. Just looking to speak to SC mgr to see if they are willing to good will this as they have test drove and denied repair annually since 2017 DU install.

Don't really feel like going to SC, pay them $420 for a 5min job. Get a $10k quote and get a substandard rebuild. QC Charge's rebuild process include drain plugs mods in case it leaks again (maybe every 30-50k event for all we know)

 

[beatle]

Well, if there's an actual failure of the DU, you wouldn't pay the diagnostic fee. They'd check the DU, of course, but when they find the failure (just as you did earlier) they should just replace the DU and not charge you.

 

[beatle]

Already pulled the sensor and checked on post #35. Just looking to speak to SC mgr to see if they are willing to good will this as they have test drove and denied repair annually since 2017 DU install.

Don't really feel like going to SC, pay them $420 for a 5min job. Get a $10k quote and get a substandard rebuild. QC Charge's rebuild process include drain plugs mods in case it leaks again (maybe every 30-50k event for all we know)

Ah, I was under the impression you were under warranty. Lots of posts here about checking the sensor before warranty expires.

 

[howardc64]

BTW, for those with basic ability to jack up the car, this car is bit of a pain to jack up to safely crawl under since jacking point = lift point. For those without fancy jackpoint type stands, here is how to "relatively quickly" get DU high enough to pull the belly pan and pull speed sensor for inspection.

I do quite a bit of DIY on auto repairs but still been dreading the jacking up process on this car (and delayed my speed sensor inspect by few weeks, wouldn't have made a difference warranty wise). The following wasn't too bad.

I didn't have a low profile jack so couldn't even get jack + hockey puck pad under the rear lift point (didn't feel like asking wife to lift up the wheel well haha)

- Drive onto a couple of pieces of ~12" wide by 1.5-2" tall wood. Maybe 1.5+ feet long. Wood will tip when first driving and quickly flatten.
- Jack up each side to place additional 4x4 or 4x6. I use 2 pieces and swapped the 12" to the top for single continuous piece under the tire.
- This was enough clearance to put a card board down, crawl down and pull the belly pan and scrape protection pieces (bunch of rocks come out so sweep that up). Just a bunch of 10mm bolts and screws to remove.

Then the speed sensor is right there on driver side. A thin and thicker tip flat head easily aid in pulling the connector plug off and pull the sensor out of the hole (10mm mounting bolt + o-ring seal)

To pull the DU will require getting jacks under the rear lifting pad so tires are off the ground. After getting tires on the wood, there is enough space to use a cross beam jack adapter + 3-4 feet long pieces of 2-4" wood to spread the load. Someone also shows how to build your own jackpoint type stands out of scissor jacks and wood

CAR JACK STAND - YouTube

Anyway, its a multi-phase process to jack up this car without a lift or $$$ jackpoint type stands.