Quaife Tesla Model S Spool Differential - QDH4T
Terms and Conditions
Orders Dispatched Within 24 hours - Excluding Weekends and Bank Holidays.
A Quaife spool differential for the Tesla Model S large drive unit, part QDH4T. It replaces the differential with a solid connection between the two output shafts.
A spool is not a differential at all, and that is the point. An open differential lets the two wheels turn at different speeds, which is what a car needs to go round a corner. A spool removes that: both outputs turn together, always, so neither wheel can spin up on its own and every bit of torque reaches the ground through both.
What that buys you is traction, and what it costs you is road manners. On a drag car, a track car or anything putting down more torque than an open diff can handle, a spool is a straightforward advantage. On a road car it is not: the wheels fight each other through every corner, which produces tyre scrub, understeer, noise in car parks and accelerated tyre wear.
This is a motorsport part. Fit it to something that competes or that never sees a wet roundabout. If you want traction on a road car, a limited slip differential does most of the same job without the compromise.
Key specifications
| Manufacturer part | Quaife QDH4T |
|---|---|
| Type | Spool differential |
| Fits | Tesla Model S large drive unit |
| Action | Solid, both outputs locked together |
| Weight | 7 kg |
Features
- Both outputs locked together, so neither wheel can spin up independently
- Far stronger than an open differential, with no gears to fail under load
- Quaife, a manufacturer whose motorsport differentials are the reference
- Direct fit to the large drive unit
Compatibility
For the Tesla Model S large drive unit.
Consider what the vehicle is for. A spool is right for drag and track use and wrong for a road car. We also supply a Quaife limited slip differential for the same drive unit, which gives most of the traction benefit while still allowing the wheels to differentiate.
Fitting means opening the drive unit. This is workshop work, and while you are in there the bearings and seals are worth replacing rather than reusing.
In the box
- 1 x Quaife spool differential
Downloads
No document is published for this differential. Quaife publish fitting data for their drive unit differentials and we can point you to it.