asavage
Member
What would be a bonus, is if we could get a baseline rotor temp (using the same or similar setup) before modding for coolant delete.
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Ceramic Bearing Update
Some interesting observations on this 3rd rebuild (prior 2 failed due to shaft rust + leaky seal)
An alternative possibility is the flame spray ( don't do this despite youtube video postings by carrepairvideos) shaft repair shop baked the rotors with a chemical sealer to eliminate the porous holes in the flame sprayed surface. This could have cause thermal damage to rotor internals (squirrel cage bar+ring current flow junctions) Unfortunately have no way to DIY test. Rotor did run fine on the last rebuild.
Anyhow, a useful note if someone want to attempt re-grease the bearings. I did it before on 2 of the bearings and their seals were fine, smoothed out as soon as grease got circulated around. It is also very hard to get this clumpy grease to go between the inner and outer race where the ball rides while the bearing is on the shaft.
Additional side notes
Some interesting observations on this 3rd rebuild (prior 2 failed due to shaft rust + leaky seal)
- I now have 6x of these expensive bearings to compare against
- The outer (facing manifold) bearing from this last install has 500 miles and a drag
- Drag is determined to be the seal (both sides of the bearing) The only contact surface is the ID seal lip, do not touch the cage+balls ( SKF link, see Technical Info Tab ) Can swap in seal from another bearing and drag is gone.
- Careful measurement of all dimensions (not easy with rubbery lips) doesn't reveal any difference between the draggy seal vs others. Rubber pliability doesn't seem any different.
An alternative possibility is the flame spray ( don't do this despite youtube video postings by carrepairvideos) shaft repair shop baked the rotors with a chemical sealer to eliminate the porous holes in the flame sprayed surface. This could have cause thermal damage to rotor internals (squirrel cage bar+ring current flow junctions) Unfortunately have no way to DIY test. Rotor did run fine on the last rebuild.
Anyhow, a useful note if someone want to attempt re-grease the bearings. I did it before on 2 of the bearings and their seals were fine, smoothed out as soon as grease got circulated around. It is also very hard to get this clumpy grease to go between the inner and outer race where the ball rides while the bearing is on the shaft.
Additional side notes
- Pulling old bearing vertically with smallest puller from my kit and without using impact gun is the most controlled. Prior effort used bigger puller, side ways, and impact gun. Scrapped the bearing seat on the shaft every time.
- Note the shaft is pressed into the rotor during manufacturing. Most people just press / tap in the bearings while other end sits on the rotor. Theoretically can affect the shaft/rotor interface but probably no where near the pressure required to do so. Just a note for reference. Not easy to anchor the shaft bottom with 70lb of rotor weight loose and floating around. Good to have 2 people.
- All the bearings even pulled by the outer race (Inner race doesn't extend enough beyond the stop to pull from) seems still good. They all spin smoothly but I've never reinstalled and run on the car. Doesn't take much force to pull them. Not suggesting anyone to reuse after pull but just an observation. I probably have 5 perfect good $115/ea ceramic bearings as souvenir.
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Coolant Delete Update
@mr_hyde had some Stainless Steel seal bore caps made. These are 55.1mm OD just like interference fit seals with SS cages. 1mm thick. Press in easily and securely with vice/press and conforms to the Aluminum bore, seals with a coat of RTV just like prior coolant seal cages, and provide ample clearance (2-3mm) to both rotor shaft and manifold with tube cut / dremeled below the circlip. Basic steps are
Post LDU assembly test holding 5 psi equivalent of vacuum of entire coolant system.
@mr_hyde had some Stainless Steel seal bore caps made. These are 55.1mm OD just like interference fit seals with SS cages. 1mm thick. Press in easily and securely with vice/press and conforms to the Aluminum bore, seals with a coat of RTV just like prior coolant seal cages, and provide ample clearance (2-3mm) to both rotor shaft and manifold with tube cut / dremeled below the circlip. Basic steps are
- Cut as much of the tube off as possible
- 20-30min of patient dremeling to get flush below the circlip. See all the broken Harbor Freight cutting discs haha. Faster if have drill press with proper attachments
- Clean off everything. Coat of RTV in seal bore, press cap in
Post LDU assembly test holding 5 psi equivalent of vacuum of entire coolant system.
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Many thanks Howard for the thought collaboration and loaning your leaky LDU for the measurements, test fitment and first install of this piece! While I respect the more complete solution of a complete replacement manifold, I'm a DIYer at heart and saw the need for this after wondering if I'd be willing to drill/sleeve/weld my own manifold to do a DIY bypass. This solution will allow anyone with basic DIY skills and tools (Dremel and bench vise) to do a coolant delete. The most challenging part of the job will obviously remain the removal/install of the LDU from the car. There isn't an easy way around that!
The production run of these caps will be arriving in a few weeks. I don't want to handle retail sales of individual units from my home so I'm hoping to find someone with a presence in the community and an existing digital storefront to handle that. I'll wholesale to shops/professionals in larger quantities.
The production run of these caps will be arriving in a few weeks. I don't want to handle retail sales of individual units from my home so I'm hoping to find someone with a presence in the community and an existing digital storefront to handle that. I'll wholesale to shops/professionals in larger quantities.
I love the way the enthusiasts work together on this forum. I wouldn't even have known about the LDU seal problem without TMC. The early S may have its foibles , but it is a pioneering vehicle and deserves to be kept on the road.
asavage
Member
Some notes & pics on my journey:
LDU rotor cooling bypass ("Coolant Delete") modification
LDU special disassembly tools
LDU rotor temperature monitor (display)
LDU rotor cooling bypass ("Coolant Delete") modification
LDU special disassembly tools
LDU rotor temperature monitor (display)
Sounds great.
Please keep us posted when you get some caps.
I could setup a webshop but as you said better to go with an existing platform.
If you change your mind I would be happy to buy one from you
Regards
// Per
Hello everyone,
I find myself in a similar situation where I received a message on my display (2014 MS P85, got the “P” version LDU in 2017) regarding a potential coolant leakage issue that may prevent my car from starting. Before I embark on the repair process (rotor coolant delete), I'm ensuring I have all the necessary parts. According to the service manual and common practice, it's essential to replace certain o-rings and seals. Does anyone have a comprehensive list of sizes for these components? While I know Tesla provides these (not all, jsut most of the) parts, I'm uncertain about their prices and would prefer to explore local shops for alternatives. (2 pcs Axle seal, HV cables,Pipes,Coolant line o-rings, etc)
Around the bearings there is a special red o-ring size is unknown?! What is the purpose using o ring on the bearing house? (I saw that cad youtube video from DIY EV Guy)
In my town there is a Toyota official service but Tesla is far away.
I've managed to locate the sizes for the bearings online (btw this community is amazing!). As I'm based in the EU, I'm opting for SKF hybrid bearings. Oil will be Dexron VI, 1.4 litres.
Silicone will be CX-80 or Permatex Ultra Black.
Additionally, for those in Portugal, I stumbled upon a coolant delete kit available at:
Tesla LDU SEAL DELETE kits | speev
Thank you in advance for any assistance provided.
I find myself in a similar situation where I received a message on my display (2014 MS P85, got the “P” version LDU in 2017) regarding a potential coolant leakage issue that may prevent my car from starting. Before I embark on the repair process (rotor coolant delete), I'm ensuring I have all the necessary parts. According to the service manual and common practice, it's essential to replace certain o-rings and seals. Does anyone have a comprehensive list of sizes for these components? While I know Tesla provides these (not all, jsut most of the) parts, I'm uncertain about their prices and would prefer to explore local shops for alternatives. (2 pcs Axle seal, HV cables,Pipes,Coolant line o-rings, etc)
Around the bearings there is a special red o-ring size is unknown?! What is the purpose using o ring on the bearing house? (I saw that cad youtube video from DIY EV Guy)
In my town there is a Toyota official service but Tesla is far away.
I've managed to locate the sizes for the bearings online (btw this community is amazing!). As I'm based in the EU, I'm opting for SKF hybrid bearings. Oil will be Dexron VI, 1.4 litres.
Silicone will be CX-80 or Permatex Ultra Black.
Additionally, for those in Portugal, I stumbled upon a coolant delete kit available at:
Tesla LDU SEAL DELETE kits | speev
Thank you in advance for any assistance provided.
brainhouston
Active Member
a bit pricey but great to see yet another alternative n 2 piece design...
blodg1
Member
Before you waste too much time and money on parts, be sure to disassemble the unit and check the resistance of each winding of the stator. If it has an internal short you need a completely new drive unit. I have three with dead shorts in the stator windings.
Good thread with lots of information and options! Took the easy way out and eliminated cooling to the rotor and diff by cutting off the original cooling manifold and just gave full flow to the stator. I removed the coolant tube and capped off either end. Been running it for a few weeks and everything seems great, possibly slightly lower stator temperatures.
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brainhouston
Active Member
nice, thanks for feedback n pics
were u able to get to both tube ends easy?
what car u have, performance or regular?
cool kit but lol at 3d printed caps
I have a performance ldu in a '72 Plymouth. Yep, the 3D printed caps work perfectly.nice, thanks for feedback n pics
were u able to get to both tube ends easy?
what car u have, performance or regular?
cool kit but lol at 3d printed caps
asavage
Member
IDK about in the Model S, but the LDU in the RAV4 EV has access to the three HV stator bolts without dropping the LDU. IOW, the orange plastic cap can be removed and an insulation resistance tester (applies 500V to the stator windings; this is not a function of a standard DMM -- I have a Fluke 1507) can be used to check stator isolation resistance without removing the LDU.
That cap is also a coolant puddling place for coolant making its way from the rotor to the inverter, so if coolant is seen there . . . it's probably in the inverter as well.
I assume such a test will become a standard part of a pre-purchase inspection for old Model S/X in future.
brainhouston
Active Member
Aren't u suppose to disconnect those first?
Otherwise you'll be sending 500v thru inverter as well...
Could be bad for inverter or at least skew the result...
blodg1
Member
Not bad for the inverter and won't narrow down the issue to the stator but will identify the potential for a stator failure.
asavage
Member
The inverter IGBTs' outputs can more than handle 500v, NP. I disconnected mine when I had my LDU on the bench two weeks ago, because I did want to eliminate the variable of the IGBTs in measuring my stator's isolation resistance, but in practice the readings connected/disconnected were nearly identical; the time slope varied, but other than that I'd say that disconnecting is not needed.
If I was performing this test on an installed LDU, and I received low readings, I'd be disconnecting the HV leads from the rear HVJB to the inverter next . . . but in theory there is no connection between the stator and the rest of the vehicle except through the IGBTs, and if one of those has a low junction resistance, then other problems would very likely have surfaced pretty fast.
If I was performing this test on an installed LDU, and I received low readings, I'd be disconnecting the HV leads from the rear HVJB to the inverter next . . . but in theory there is no connection between the stator and the rest of the vehicle except through the IGBTs, and if one of those has a low junction resistance, then other problems would very likely have surfaced pretty fast.
brainhouston
Active Member
good to know
i was just always under impression that backfeeding voltage to the circuit is not a good idea but maybe its ok in this case since regen technically does same thing...
Nice implementation of the LDU non removal fix! I would suggest 3d print a connector that connects the pipe that goes to the heat exchanger to the main coolant line instead of capping it.
Good job on the delete! I thought about routing coolant back to the tube, but I cannot come up with any benefit to bleeding off some coolant to the top of the diff heat exchanger. I think I prefer increased flow through the stator, and keeping it simple.
