Technical comparison · Updated August 2026
Tesla Drive Units: A Builder's Reference
Four Tesla drive units account for almost every Tesla-powered conversion on the road. They are not four points on one line from small to large. Two different motor technologies, two different generations of inverter, and two different sets of aftermarket support are spread across them, and those splits matter more to a build than the horsepower figure does.
The first fork is the motor itself. The Model S and X units, and the Model 3/Y front unit, use AC induction motors: no magnets, no voltage on the phases when the rotor is spun by the road. The Model 3/Y rear unit uses an internal permanent magnet motor, which is more efficient and more compact for the same output, but is always magnetised and therefore always generating once it turns. The second fork is age. The Model S and X units are a closed pool of salvage with a deep rebuild parts ecosystem behind them. The Model 3 and Y units are abundant, newer, technically better, and almost unsupported for repair.
Each of these four is a family rather than a single part number, and the variants inside a family change the price and sometimes the control board without changing the machine. Those are covered in Know which variant you are buying, below the table.
Large Drive Unit
LDU · S/X rear · to 2020
The original, and still the most powerful of the four. Heaviest and physically largest, though the inverter can be unbolted and remote-mounted to claw back the width. Base and Sport are the same motor with different inverters.
335–475 kW450 – 650 Nm · 9.73:1 · 132 kg
AC inductionSmall Drive Unit
SDU · S/X · to 2020
Two thirds of the weight of an LDU for two thirds of the power. One machine in two horizontally mirrored cases: the front FSDU sits at a 45-degree angle, the rear RSDU lays flat. Identical internals, identical output.
220 kW330 Nm · 9.34:1 · 90 kg
AC inductionModel 3/Y Rear Drive Unit
3/Y RDU · 2017 on
Permanent magnet motor with an external electric oil pump, and the best efficiency of the four by a wide margin. Millions were built, so supply is not a concern. Comes in multiple variants and power outputs.
203–239 kW330 – 420 Nm · 9.03:1 · 80 kg
Permanent magnetModel 3/Y Front Drive Unit
3/Y FDU · 2017 on
Induction motor in its own smaller housing, and the lightest and least powerful of the line up. It shares the same inverter generation as the rear and the 9.03:1 ratio, but not much else. Currently the least supported by aftermarket controllers.
121–158 kW163 – 240 Nm · 9.03:1 · 72 kg
AC inductionTesla does not publish specifications for these drive units as standalone parts. Every power, torque, current and voltage figure cited has been compiled by the conversion community from teardowns, reverse engineering, vendor listings and the manuals of the donor cars. Sources disagree, and they do not always share a rating basis, so treat these as a guide to how the four units compare with each other rather than as a datasheet to design against.
→ Swipe the table sideways
| Large Drive UnitLDU · MODEL S/X | Small Drive UnitSDU · MODEL S/X | Model 3/Y Rear Drive UnitRDU · MODEL 3/Y | Model 3/Y Front Drive UnitFDU · MODEL 3/Y | |
|---|---|---|---|---|
| What it is | LDU | SDU | 3/Y RDU | 3/Y FDU |
| Where it came from | Rear-wheel-drive Model S and X, and the rear axle of every P-badged dual-motor S and X. The Toyota RAV4 EV and Mercedes B-Class EV used a related unit rather than the same one, covered below. | Both axles of non-performance dual-motor Model S and X (70D through 100D), the front axle of the performance cars, whose rear axle got an LDU, and the rear axle of the 2019–21 Raven cars, whose front axle got a permanent magnet unit instead. | Every Model 3 and Model Y ever built, rear-drive and all-wheel-drive alike. | The front axle of every all-wheel-drive Model 3 and Model Y. |
| Variants to know about | Base and Sport. Same motor and gearbox, different inverter, and they need different AEM control boards. A third configuration went into the Toyota and Mercedes cars, built front-wheel-drive with the internals reversed. See below. | FSDU and RSDU, the front and rear cases, mirrored left to right with identical internals. Later rear units also came with an external oil filter and pump in place of the internal pump. That changes the reverse-mounting job and the controller choice together, so it is the variant to identify before buying. See below. | 970, 980 and 990. Tesla numbers these 1120970, 1120980 and 1120990 with a revision suffix, and the last three digits are used as shorthand from here on. The 970 is the original IGBT unit; the 980 and 990 are silicon carbide and differ on current, at 800 A and 600 A. See below. | 960, numbered the same way, with copper or aluminium rotors depending on trim. The difference matters far less here than on the rear unit. |
| Motor type | Induction. Three-phase four-pole AC induction. No magnets, so it free-wheels with no drag and puts no voltage on the phases when the car is towed or coasting. | Induction. Same technology and the same advantages as the LDU, in a smaller frame. | Permanent magnet. An internal permanent magnet synchronous reluctance motor. Markedly more efficient than induction at low to medium speeds, but its fixed magnetic field creates physical drag at high RPMs, where an induction motor is more efficient. | Induction. Tesla put an induction rotor in the front on purpose, so it can free-wheel while the rear magnet motor does the work. |
| Rotor position sensing | Encoder. A four-wire quadrature encoder at the far end of the motor, fed back through the main 23-pin connector. Reliable when intact, and the single most common cause of a unit that will not spin properly. | Encoder. Same quadrature arrangement as the LDU, FSDU and RSDU alike. | Resolver. An analogue resolver rather than an optical encoder. Nothing to go out of alignment, and no known failure pattern. | Resolver. Same as the rear unit. |
| Weight, bare unit | Heaviest. 132 kg (291 lb), before half-shafts. | Middle. 90 kg (198 lb), FSDU and RSDU alike. | Light. 80 kg (176 lb), inverter included. | Lightest. 72 kg (158 lb), in a smaller housing of its own rather than a shortened version of the rear unit. |
| Dimensions | Largest. Approx. 852 × 619 × 327 mm (33.53 × 24.37 × 12.87 in). Wider and deeper than anything else here, though not the tallest, with the inverter bolted onto the outside of the gearbox casing rather than buried in it. | Compact, in two orientations. Same internal volume both ways. The RSDU lays flat; the FSDU sits at a 45-degree angle, and the two are horizontally mirrored. | Smallest footprint. Roughly 676 × 554 × 353 mm (26.6 × 21.8 × 13.9 in) as it sits, and the most tightly integrated of the four. | Smallest of the four. A different and smaller housing than the rear unit, not the same case with a shorter motor in it, and horizontally mirrored from the 3/Y RDU. |
| What it makes | LDU | SDU | 3/Y RDU | 3/Y FDU |
| Peak power | Highest. 335 kW (449 hp) as a Base unit, up to 475 kW (637 hp) as a Sport. | Strong for the size. 220 kW (295 hp), FSDU and RSDU alike. | Strongest of the four after the LDU, and the RWD unit leads. 239 kW at 5,525 rpm on the RWD variant, 219 kW at 5,075 rpm on Performance and 203 kW at 6,700 rpm on AWD. The rear unit out of a single-motor car is the most powerful of the three, which is the opposite of what most listings imply. | Lowest here. 121 kW at 8,275 rpm on the standard motor, 158 kW at 8,275 rpm on the performance one. Adequate as half of an all-wheel-drive pair, marginal on its own in anything heavy. |
| Peak torque | Highest. 450 Nm (332 lb-ft) Base, up to 650 Nm (480 lb-ft) Sport, before the 9.73:1 reduction. | Moderate. 330 Nm (243 lb-ft). | Second only to the LDU. 420 Nm on the RWD and Performance variants across 325–5,200 rpm, 330 Nm on AWD. Well clear of the SDU either way. | Lowest here. 163 Nm standard and 240 Nm performance, both quoted across 125–8,375 rpm. |
| Sustained output | No published rating. Tesla does not publish a continuous power figure for any drive unit on this page. The peak numbers in the two rows above are short-duration ratings taken from a cold start. Sustained output is determined by the cooling system, the ambient temperature and the duty cycle of the build, not by the unit itself. | No verified rating. Figures of 35 kW continuous and 90 kW for twelve minutes circulate widely on EV parts sites. They appear verbatim across multiple resellers with no primary source behind them, and they cannot be traced to Tesla or to any published independent test. Treat them as a rule of thumb, not a specification. | No published rating. Newer power electronics and a more integrated thermal path than the S/X units give reason to expect better sustained output, but no figure is published and no independent test result is available. | No published rating. Same situation as the rear unit. |
| Maximum motor speed | Around 18,000 rpm mechanically. All four units sit in the same range, so this is not a differentiator between them. Tesla's own control software held the LDU well below the mechanical limit, which is part of what an aftermarket controller unlocks. | Around 18,000 rpm. | 18,447 rpm maximum rotor speed, the only one of the four with a figure this specific on record. | Around 18,000 rpm. |
| Working voltage | 400 V class. 240–404 V DC as Tesla ran it, with a 450 V DC link capacitor as the hard ceiling. Every unit on this page is a 400 V class device: none of them is an 800 V drive unit, and none should be designed as one. | 400 V class. 200–420 V DC, up to 650 A. | 400 V class. The three variants are quoted at 350 V RWD, 335 V AWD and 320 V Performance. | 400 V class. Same as the rear unit. |
| Gearbox & driveline | LDU | SDU | 3/Y RDU | 3/Y FDU |
| Gear ratio | 9.73:1, single speed. The four ratios here span less than eight percent, so gearing is not how you choose between them. None of these is a long-legged highway ratio: all of them assume a motor happy at five figures. | 9.34:1, single speed. Identical gears in both, stacked differently. | 9.03:1, single speed. Tesla publishes 9.03:1; teardowns measure 9.037:1 from a 81/31 first stage and a 83/24 final. | 9.03:1, single speed. The same ratio as the rear unit, in a different gearcase. |
| Changing the ratio | Available. A 4.1:1 reduction gearset exists, which turns the unit into something you can run through a prop shaft to a live axle. | Nothing available. No aftermarket gearset is made for the FSDU or the RSDU. What you buy is the ratio you keep. | Available. Fellten's 3.54:1 reduction gearset, listed for the rear drive unit. | Not a straight swap. Fellten lists the 3.54:1 set for the rear unit. Resellers disagree on the front: some advertise it as compatible, at least one states it needs internal modification first. Ask before ordering. |
| Limited-slip diff | Two options. Quaife's QDH2T and an ACEV helical unit, the widest choice of the four. | Available, both variants. Quaife's QDH3T. The FSDU and the RSDU use identical differentials, so one part covers both. That is not true of the M3DU pair. | Available. Quaife's QDH7T. | Nothing listed. Quaife's QDH7T is described by Fellten and its stockists as a replacement for Model 3 rear drive unit differentials. No equivalent is listed for the front unit. |
| Half-shaft interface | Model S/X spline, 44 mm seal shoulder. Stub axle adapters are widely made for this family. | Model S/X spline, 44 mm seal shoulder. The FSDU also uses an intermediate shaft on the passenger side, so that side has a female splined inner CV cup. | Same spline as the S/X units, with a 40 mm seal shoulder rather than 44 mm. | Identical to the 3/Y RDU. |
| Installation | LDU | SDU | 3/Y RDU | 3/Y FDU |
| Mounting | Widest. Three OEM bushings: front, back, and stator side. Tesla used one rear subframe for both Performance and Long Range cars, so an RSDU shares these mounting points and swaps straight in. | Two geometries to choose from. The RSDU lays flat in a subframe and the inverter is on the passenger side; the FSDU sits at a 45-degree angle, and the inverter is on the driver's side. The two are horizontally mirrored. | Compact and square. The easiest of the four to package, and the easiest to fabricate a mount for. Horizontally mirrored against the front unit, the same way the SDU pair is. | Compact, and its own shape. Easy to package, but a 3/Y RDU mount will not carry it. Measure this unit rather than working from the rear one. |
| CAD model | Model on GrabCAD. Every model linked in this row is a community upload or a 3D scan rather than Tesla data, so they are good enough for mock-up and clearance checks and not a substitute for measuring the unit in front of you. Downloads sit behind a free GrabCAD sign-in. | RSDU scan and FSDU scan on GrabCAD. | Model on GrabCAD. | Model on GrabCAD. |
| Divorcing the inverter | Kits are available. Unbolting the inverter and remote-mounting it, commonly called divorcing, is the standard remedy for this unit's width. More than one supplier sells a remote inverter kit with a billet mount, block-off plates, gaskets and coolant bypass plates. Note that divorcing any of these four adds length to three phase leads, which is an EMI and inductance question as much as a mechanical one. | Possible, nothing packaged. The inverter can be separated in principle, as on all four units here, but no relocation kit is sold for it. Fabrication required. | Nothing known available. Separating the inverter is possible in principle, as on all four units here, but no relocation kit is on sale for it that Westside EV can point to. Fabrication required. | Nothing known available. Same as the rear unit, and the smaller housing means a rear unit bracket would not carry over even if one appeared. |
| Running it reversed | Hardware modification required. At minimum, a reverse-drive pump must be fitted. Phase swap also required if the OEM logic board is retained. See the controller comparison. The Toyota and Mercedes units left the factory reversed, but these are hard to find. | Hardware modification required. At minimum, the oil pump must be modified. RSDU and FSDU oil pump reverse kits available to simplify the process. Phase swap also required if the OEM logic board is retained. See the controller comparison. Busbar tabs for the phase swap fit both variants. External-pump RSDUs need no oil pump modification, but have their own caveats (covered below). | Hardware modification possibly required. All variants feature an external pump, so no pump mod required. Phase swap required if the OEM logic board is retained. | Hardware modification possibly required. All variants feature an external pump, so no pump mod required. Phase swap required if the OEM logic board is retained. |
| Cooling | The gear case is oil cooled, the stator and rotor are coolant cooled. Coolant enters inlet and splits into two paths. Path A flows through stator jacket, then inverter. Path B flows through rotor shaft then to differential. Both paths then recombine and exit via the same outlet. Coolant delete and bypass kits eliminate the path through the rotor shaft and the problematic seal, and in some cases the differential as well. | The rotor and stator are oil cooled. Internal mechanical oil pump circulates oil through motor and gearbox. Heat exchanger transfers heat from oil to coolant. Coolant also flows through inverter separately, but never enters any other part of the motor and thus no risk of leak. Some units have an external electric oil pump instead of the internal mechanical one. | The rotor and stator are oil cooled. External electric oil pump circulates oil through motor and gearbox. Heat exchanger transfers heat from oil to coolant. Coolant also flows through inverter separately, but never enters any other part of the motor and thus no risk of leak. | The rotor and stator are oil cooled. External electric oil pump circulates oil through motor and gearbox. Heat exchanger transfers heat from oil to coolant. Coolant also flows through inverter separately, but never enters any other part of the motor and thus no risk of leak. |
| HV connections | Proprietary and awkward. 50 mm² shielded cables with lugs and EMC glands that Tesla does not sell separately, over roughly 17.3 mm insulation into a 26.2 mm casting, and the gland nuts are usually corroded by the time you get one. Aftermarket glands exist. | Hard to source. 35 mm² shielded cables with Rosenberger HPK series connectors, which are not available through conventional vendors. | A documented connector. A two-pin TE HC-STAK 90 degree part, 2840900-1, with the mating half commercially available. Easier to source than either older family. | A documented connector. As on the rear unit. |
| Inverter & control | LDU | SDU | 3/Y RDU | 3/Y FDU |
| Inverter hardware | IGBT. Base and Sport use different transistors, the Sport being the higher-current part. It bolts to the gearbox casing over square o-ringed coolant passages, which is why remote inverter kits require coolant plates. | IGBT, integrated. Built into the casting, with the phase current sensors potted in place. Identical in both variants. | Silicon carbide, on everything but the earliest unit. Twenty-four SiC devices and a TI C2000 Delfino MCU, a full generation ahead of the S/X inverters. The original 970 is the IGBT one; both the 980 and the 990 are silicon carbide, and they differ on current rather than on device technology. | Same inverter family as the rear unit, and the same reason to check the part number rather than assume. |
| Getting at the logic board | Easiest. The board lifts out and the drive unit connectors plug straight into a replacement. | Moderate. The potted current sensors have to come out before a replacement board goes in. Same job for both. | Hardest by a distance. Extensive soldering, plus components transferred across from the original board. Not a practical job for most builders. | Hardest by a distance. Same as the rear unit. |
| Dynam Labs VCU+ | Supported. Listed by Dynam Labs, with drive unit flashing built into the VCU. | Both variants supported. Dynam Labs lists the RSDU as the SDU and the FSDU as the FDU, and either can run on its own rather than only as a slave. | Supported. Listed as Model 3 Rear. | Not listed today. The 3/Y FDU does not currently appear on Dynam Labs' supported list. This is the fastest-evolving motor option on this page, so ask before ruling the unit out. |
| EV Controls T-2C | Supported. All Model S and X large drive units. | RSDU yes, FSDU only as a slave. RSDUs from 70D through 100D run on their own or as half of a pair. EV Controls states front units lack the accelerator, brake and logic board wiring for a two-wheel-drive application, so an FSDU can only be the second half of a dual-motor pair. | Supported. Model 3 and Y rear units in two-wheel-drive applications, and in dual-motor all-wheel-drive. | Slave only, behind a 3/Y RDU. The T-2C runs this unit as the front half of a Model 3/Y dual-motor powertrain with a 3/Y RDU as the master. It will not drive a car on its own, and it will not sit behind an LDU or an SDU. |
| AEM VCU275/300 | Supported, two part numbers. Separate inverter control boards for Base (30-8402) and Sport (30-8410). Buy the one that matches your unit. | Both variants, one board. The 30-8403 covers either, and AEM states direction can be changed over CAN so the unit can be mounted whichever way round suits. | Not supported. AEM does not offer a Model 3 or Y inverter control board. | Not supported. Same as the rear unit. |
| Openinverter | Mature. The V4b logic board has been in service for years and is the most proven open-source option here. | Mature, both variants. One board covers non-Raven 2012–2020 units front and rear, and unlike the T-2C it makes an FSDU usable on its own. | New and explicitly unfinished. The V3.2 Model 3 board was released as a fully open design in March 2026, covering front and rear units. It is sold to testers rather than as a finished product, and it needs soldering. Treat it as a project, not a part. | The only standalone path, and it takes work. The same V3.2 board will run this unit on its own, but not as it ships: some components on the board have to be swapped and the matching firmware loaded. All the beta caveats of the rear unit apply, with a hardware modification on top. |
| Buying & owning | LDU | SDU | 3/Y RDU | 3/Y FDU |
| Availability | Finite and thinning. Production ended, so the supply is a fixed and shrinking pool of salvage. Base units are still easy to find. Sport units are in higher demand, and priced accordingly. | Steady, and lopsided. The FSDU is the easiest S/X unit of any kind to find, because every dual-motor car has one including the performance cars whose rear LDU is the sought-after half. The RSDU is scarcer and costs more. | Abundant and growing. Millions of donor cars, and the supply increases every year. | Abundant. One from every all-wheel-drive car, and the least in demand of the four. |
| Typical used price | Base is inexpensive, Sport is not. Base units trade near the bottom of the S/X range. Sport units are in higher demand and carry a clear premium. | The least expensive S/X units. An FSDU undercuts an RSDU, and both undercut any LDU. | Wide spread, and it tracks the part number. A high-current 980 runs to roughly twice a 990. Complete Performance assemblies sold with the subframe and suspension carry a further premium again. | Cheapest of the four. Front units attract the least competition of anything on this page. |
| Ready to run from Westside EV | Sport LDU, rebuilt and test-spun with the controller of your choice. | RSDU and FSDU, at the same price either way. | Performance 980 rear unit. | Not currently offered as a ready-to-run unit. Ask. |
| Known weak points | The rotor coolant seal. The shaft seal at the coolant inlet lets coolant into the motor, which rusts the internals into sludge. Pull the encoder and look inside before you buy any LDU, at any price. The encoder itself and the rotor bearings are the other two things that go. | Bearings and axle seals. Wear items on a high-mileage unit rather than a design flaw, and the same in both variants. There is no coolant path into this motor, so the LDU's worst failure has no equivalent here. | Check which oil it takes. Two versions exist: one where the gear oil also runs through the motor and one where it does not. The wet-motor version needs FUCHS BluEV EDF 7005 specifically, and running anything else degrades the motor over time. Black oil identifies that version. Beyond that, too few high-mileage teardowns are published to name a characteristic failure. | Not yet well documented. Same as the rear unit. |
| Rebuild parts | Deepest of the four. Full rebuild kits, rotor bearing sets, hybrid ceramic bearings, coolant delete manifolds and the correct spanner sockets are all stocked items. | Good. A full rebuild kit covers both variants, plus replacement current sensors and inverter headers. | Thin. A limited-slip differential and a gearset exist. A rebuild kit does not. If an M3DU fails, the realistic answer today is another unit. | Thinner still. No rebuild kit, and neither the limited-slip differential nor the gearset that exist for the rear unit is listed for this one. |
| The short version | LDU | SDU | 3/Y RDU | 3/Y FDU |
| Pick it if | You want the most power available from a Tesla unit, you have the room and the payload for it, and you value the deepest rebuild parts supply of the four. | You want most of a Tesla drive unit's character in a package that will actually fit, with induction simplicity, two mounting geometries to choose between, and support from all four major controllers. | You want the most torque available short of an LDU in the smallest package, you value the efficiency and the newer power electronics, and you are comfortable running a unit you cannot currently have rebuilt. | You are building all-wheel drive on Model 3 hardware, which is the configuration the supporting controllers are aimed at, or you want a modern unit in something light where 150 kW is plenty. |
| Think twice if | The chassis is narrow, mass behind the axle line is a concern, or you are unwilling to inspect for coolant ingress before buying. | You need more than 220 kW, you want the option of changing the gear ratio later, or you are building two-wheel drive on a T-2C with an FSDU, which will not work. | You want AEM control, a rebuild path, or a motor that free-wheels harmlessly when the inverter is off. | You want the most power per dollar, you need a limited-slip differential or a ratio change, or you need it to drive a car on its own. Standalone today means a modified Openinverter board, because the T-2C will only run this unit behind a 3/Y RDU. |
Know which variant you are buying
Each column above is a family, not a part number. Within a family the motor and the gearbox are usually identical and the inverter is not, which is why these belong here rather than as separate columns in the table. The distinctions still decide what you pay and, in two cases, which control board you need.
Large Drive Unit: Base or Sport
| Base LDU | Sport LDU | |
|---|---|---|
| Donor cars | Rear-wheel-drive Model S and X. | The rear axle of P-badged cars: P85, P85D, P90D, P100D. |
| Motor and gearbox | Identical. Same castings, same 9.73:1 reduction, same bearings, same seals, same rebuild kits. | |
| Inverter | Lower-current transistors. | Higher-current transistors. This is the whole difference. |
| Output | 335 kW / 450 Nm. | Up to 475 kW / 650 Nm. |
| AEM control board | 30-8402. | 30-8410. Not interchangeable with the Base board. |
| Telling them apart | Sticker reads BASE, and the phase board PCB is green. | Sticker reads SPORT, and the phase board PCB is red. |
| Toyota and Mercedes units | The RAV4 EV and the B-Class EV, sold in the States as the B250e, used a front-wheel-drive version of this drive unit rather than the Model S one. The motor sits the other way round with the differential behind it, the gearset and oil pump are reversed to match, and the motor turns the opposite direction to drive the car forward. They also carry a parking pawl that mechanically locks the input shaft in park, which no Model S or X unit has. For a reverse-mounted build, or for anyone who wants a mechanical park lock without fabricating one, that combination is close to ideal. They turn up rarely enough in salvage that it is not something to plan a build around. | |
| If in doubt | Check that the motor sticker and the inverter sticker agree with each other and with the listing. Stickers get swapped and go missing; the phase board colour does not, which makes it the more reliable check. Units advertised as performance that turn out to be Base are a recurring problem in the used market. | |
Small Drive Unit: RSDU or FSDU
| RSDU | FSDU | |
|---|---|---|
| Motor, gears, output | Identical. Same 220 kW, same 330 Nm, same 9.34:1, same 90 kg, same encoder, same inverter, same rebuild kit, same LSD. | |
| Case | Lays flat, sitting low in a rear subframe. | Sits at a 45-degree angle, and horizontally mirrored relative to the RSDU. |
| Modifying the pump | Essentially the same job either variant: tap and plug the original ports, drill new ones, and replace or adjust the spring to set pressure to 1 bar. The FSDU pump also requires one of the nozzles to be replaced with a 90-degree hose barb fitting, and it must be mounted 180 degrees from its original clocking. The kit includes a custom mounting bracket. | |
| Refitting it | Bolt-in pickup canister and spring. | The case needs slight machining to take the bracket. |
| EV Controls T-2C | Runs on its own, or as half of a pair. | Slave only. Cannot drive a two-wheel-drive car. |
| Availability and price | Scarcer, and dearer. | The most plentiful S/X unit there is, and the cheapest. |
| External pump units | Later rear units, including those in the 2018 Model X and 2019–21 Raven cars, carry an external oil filter and pump in place of the internal pump. They otherwise look like any other RSDU, so the external filter and pump hanging off the casing are what identify one in a listing. | |
| Driving that pump | While there is no internal pump to modify for a reverse-mounted build, no aftermarket logic board is able to control the pump speed yet. However, you can run the pump in failsafe mode, which runs it at full speed continuously, or build a small controller that speaks to it over LIN. Openinverter has worked out the LIN messages. Neither EV Controls nor Dynam Labs lists these units specifically, so ask before buying one if the plan is to keep Tesla's board. | |
Model 3/Y rear: 970, 980 or 990
| 970 | 980 | 990 | |
|---|---|---|---|
| Part number | 1120970-00-F | 1120980-00-G | 1120990-00-G, -H and -J |
| Inverter | IGBT. | Silicon carbide MOSFET. | Silicon carbide MOSFET, low current. |
| Max current | 800 A | 800 A | 600 A |
| Fitted to | Original RWD cars, and Performance cars built with a binned unit. | Early all-wheel-drive cars. | Later all-wheel-drive cars, and the one still fitted from 2022. |
| Motor code | Not recorded. | 3D1 | 3D5 |
| Reman part | None listed. | 1521365-00-B | 1521487-00-A |
| Why it matters | The 800 A units will take a third more current than the 600 A one, on hardware that is visually near-identical. Note that the power figures Tesla quotes are given per car variant rather than per part number, so the two do not map one to one. The full part number is stamped in the housing and printed on a sticker; the orange placard on the motor carries the motor code. | ||
The bigger unit is not automatically the right buy. Extra output is only available if the pack can deliver the current, the cooling can absorb the heat, and the chassis can use the torque. On a light car with a modest pack, a Base LDU or a 990 and the money saved is often the better build.
Raven and Plaid, and why they are not on this page
Raven changed the front unit. From 2019, Tesla replaced the Model S and X front induction motor with a repackaged version of the Model 3 permanent magnet motor. It looks like an FSDU and it is listed as a front drive unit, but it is a different machine. The Raven rear is the opposite case: it stayed an AC induction SDU, and it is the external oil pump, not the motor, that sets it apart. Openinverter's SDU board covers non-Raven 2012–2020 units only, and EV Controls states its support runs up to but not including the Raven cars. Check the donor year before buying any Model S or X front unit.
Plaid is outside the scope of this page. The Plaid rear is not one drive unit. Tesla's own service documentation treats it as a left and a right inverter with independent motors, one per wheel, which means it does not compare against anything above on gear ratio, mounting or inverter architecture. Its rotors are carbon-sleeved, and none of the four controllers Westside EV stocks supports it. Covering it would mean covering a different control ecosystem entirely.
In short: if the donor was a 2019 or later Model S or X, or any Plaid, none of the recommendations on this page apply. Confirm the donor before purchase.
None of these units will run in a Tesla vehicle once converted, and none of them will run at all without an aftermarket controller. Which controller to use is a separate question, covered in the drive unit controller comparison.
Peak figures are short-duration ratings. Every number in the power and torque rows assumes a pack able to deliver the current and a cooling system able to remove the heat, and none of them is a continuous rating. Size the build around the cooling system and the intended duty cycle rather than the headline figure.
Part numbers and motor codes matter more than model names. A 3/Y RDU can be a silicon carbide 980 or a lower-current IGBT 990, and they look alike. An LDU can be Base or Sport. An SDU can be an FSDU or an RSDU. Get the identifying marks from the seller before you pay.
LDU, SDU, FSDU, RSDU, M3DU, 3/Y RDU and 3/Y FDU are shorthand, not Tesla designations. Tesla identifies these units by part number and by motor code, and a seller quoting a short name is quoting a nickname. The short forms are used on this page because they are the terms in common use and because they fit in a table cell. Quote the part number when buying.
A drive unit is not the whole bill. Whatever the unit itself costs, budget separately for contactors, precharge, wiring, cooling, half-shafts and the controller. Prices are linked rather than quoted on this page, so what you see when you click is current.
Not sure which of these fits? Tell us what you are building, how much room you have, where the unit is mounted and which way it needs to spin, and we will tell you honestly which one to buy, including the ones we do not stock.