Tesla Large Drive Unit Gear Set 4.1:1
Terms and Conditions
Orders Dispatched Within 24 hours - Excluding Weekends and Bank Holidays.
A 4.1:1 gearset for the Tesla large drive unit. It replaces the standard reduction gears with a much taller ratio, which is what a converted vehicle needs once the drive unit is turning prop shafts rather than a Model S or X's own driveshafts.
The standard large drive unit is geared to launch a heavy saloon from a standstill, so in a conversion it runs out of road speed early and leaves the motor spinning hard at cruise. Fitting the 4.1:1 set moves the work back to where it belongs: paired with a conventional differential and axle, the overall drive ends up close to the original Tesla arrangement, keeping the torque delivery while letting the vehicle pull a usable top speed. The gears are helical and ground, so the unit stays quiet and takes load in the way the original set did.
Key specifications
| Manufacturer part | TESLAGEARSET411 |
|---|---|
| Type | Reduction gearset, replaces the standard gears |
| Gear ratio | 4.1:1 |
| Gear type | Helical, ground |
| Fitment | Tesla large drive unit, as used in Model S and Model X |
| Installation | Drive unit strip and rebuild, professional fit |
| Oil on refill | 1.4 litres |
| Weight | 6.50 kg |
| Supplied as | Gearset only |
Features
- A taller ratio than standard, suited to a driveline that runs through prop shafts and a conventional final drive
- Paired with a normal differential, the overall gearing lands close to the original Tesla setup, so torque delivery stays familiar
- Helical ground gears for quiet running and durability under sustained load
- Allows the drive unit to be mounted centrally with an output at each end, the usual layout for a 4x4 conversion
- Fitted in our own workshop as part of drive unit rebuilds, so the procedure is known rather than theoretical
Compatibility
Fits the Tesla large drive unit. The unit has to come apart to fit it, which is the moment to deal with everything else inside the casing. Most builds take the Quaife QDH2T limited slip differential at the same time, and a rebuild is also the point to fit a reverse drive oil pump and fresh output shaft seals rather than going back in later.
If the drive unit is going into a vehicle with a conventional driveline, Defender prop shaft stumps give you a flange at each output.
In the box
- 1 x Tesla large drive unit gearset, 4.1:1
The gearset only. Bearings, seals, oil and any parts you choose to renew during the rebuild are not included.
Downloads
Fitting this gearset is part of our large drive unit rebuild procedure. Contact us if you need the fitting details for your own workshop.
Worldwide Shipping
Fellten offers worldwide shipping through trusted carriers including UPS, DHL, and pallet freight services. Whether you're a professional installer or a classic car enthusiast, we ensure your order is packed securely and delivered efficiently.
We are fully certified to ship dangerous goods, including lithium-ion batteries, in compliance with all international regulations.
For UK orders, most in-stock items are eligible for next working day delivery if placed before 12:00 PM. Orders placed after this time will be shipped on the next working day. Please note that all delivery estimates are stock-dependent, and you will be notified if any delays are expected.
Shipping costs are calculated at checkout based on your location and order details, so you’ll always have clear and accurate pricing before completing your purchase.
Payments are securely processed using Stripe. We accept all major credit and debit cards.
