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Mk3 Focus ST Quaife ATB Differential - Fully Fitted at mountune HQ

£999.17 You Save 8% (£83.34)

The Quaife ATB helical LSD differential for mk3 Focus ST fits the MMT6 gearbox. A direct replacement for the standard Ford open differential, the Quaife differential transforms your car's performance.

Unlike a conventional plate-style limited slip differential, the Quaife differential relies on gears rather than clutch plates for its operation. That means it is much smoother in operation and never locks harshly with a set pre-load of wheel slip across the driven axle.

Instead, the Quaife differential automatically biases the torque away from the spinning wheel, across the axle to a constantly varying degree.

Benefits over a standard open differential:

  • maximise traction
  • minimise wheel spin
  • reduced torque steer and snatching in front wheel drive cars
  • a maintenance-free design which retains the standard oil lubrication

Quaife differentials are proven in circuit and drag racing, rallying and road use. All Quaife differentials are produced from Corus steel billets, and are CAD-designed and CNC machined before being inspected to ISO 9001 standards.

Fitted price includes the following:
  • Focus ST Quaife ATB differential
  • Installation kit (new bearings, seals and bolts)
  • Transmission fluid

Please note: the price shown for this product includes installation* at mountune HQ in Hutton, Essex and is not transferrable to any other Ford dealer or installer.

Please specify your preferred installation date in the 'notes' section when checking-out; our workshop team will then contact you back to confirm this date. If we can't accommodate your preferred choice, the team will discuss with you other available dates, that are still acceptable to you.

*subject to availability. Lead times may vary. Contact us for more information.

Customer Reviews
5.0 Based on 15 Reviews
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Filter Reviews:
    Richard R.
    United Kingdom United Kingdom
    Upgrade your Diff First People

    I can not explain just how much better my car drives, corners, brakes and accelerates, since I had the Quaife ATB Differential fitted at Mountune. This should have been fitted to the ST as standard. Straight line acceleration no longer has the car tracking all over the place, my car now longer cares about the dips and groves in the road in my daily driving. I can accelerate hard from a stop and not have one wheel break lose and have that tire spinning, stopping the car from accelerating. The car no longer pulls me into the inside (and slows the car down) on my local mini roundabout, but it now takes a slightly wider line, which I now prefer and that is purely because the diff is doing its job. First sweeping bends are now a breeze with the car now able to speed up or slow down in the bend without giving me a heart attack about what the car is going to do next in the bend. Even braking from speed is better, if you have ever had to quickly slow down from a high rate of speed and had your ST buck & weave under braking. Then you will understand what I am trying to say. My ST now brakes without any drama I have so much more confidence in my car now that I have had the Diff fitted. If you are ever going to do any form of upgrade to your ST, then you should save your money & start here. You will save loads of time & money on power upgrades that you can not truly use on the roads until you do this upgrade. There is no upgrade that will do more for your car than fitting a Limited Slip Differential. It is something that should have been fitted to the car as standard & makes a already very good car into an amazingly great car. Do It People you will not regret it.

    Garry V.
    United Kingdom United Kingdom
    Mk3 focus st quaife ATB differential I install at mountune hq

    I purchased this item in the pre lockdown sale. The communication with fred was excellent always replied to my calls or emails. The service from fred was excellent on the day of installation and couldnt do enough for me. The diff was the last part to be fitted as I already had the mr300 kit and short shift and rear roll restrictor the car Is an awesome drive now thanks again Fred

    Dan L.
    United Kingdom United Kingdom
    Should be everyone's first mod

    Wow - just wow. Completely transforms the car and makes it so much more fun to drive, the personal service received at Mountune HQ was incredible with a nice comfortable waiting room with amenities. Ryan welcomed me and took me through everything that was going to be done and answered all of my questions about other aspects of the car. The steering wheel was noticeably heavier at first but you get used to it pretty quickly. Cornering (even with stock suspension) is an absolute blast now, launching and hard acceleration is so planted that the car feels like it's on rails! I bought mine during the Christmas sales which saved a pretty penny but it's easily WORTH the full price. If I were to have another ST then this is hands down the first modification that I do - I had the RS clutch fitted at the same time as it just made sense. Speaking to Ryan prior to the install made this so easy to get sorted.