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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 Based on 13 Reviews
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Filter Reviews:
    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.

    Neil C.
    A transformation

    I would say that if I had to choose just one upgrade for the ST then the Quaife lsd would be it, it really does make it feel like a different car. For me it improves the steering feel (actually at all speeds) but when driving through corners 'enthusiastically' on your favourite roads it is just SO much more capable and confidence inspiring. Overtaking also fees much safer and not at all the 'white knuckle ride' which it sometimes could be with the standard diff / torque vectoring. When you drive the ST with the Quaife diff you can't help but wander why they didn't fit them as standard as the slight increase in cost from new would have been so worth it, perhaps they didn't want it snapping at the heels of the RS? The service at Mountune was absolutely superb where Ryan looked after us very well and explained everything in detail. Highly recommended.

    Quaife Limited Slip Differential MK 3.5 Focus ST

    This upgrade transforms the car and with 280bhp+ FWD it is highly recommended. The noticeable difference to me is that the torque steer under hard acceleration is dramatically reduced which is great because you can be more secure holding the wheel one handed whilst your other hand shifts gears. Second noticeable difference is it is much harder to wheel spin off the line, particularly pulling out of junctions in first gear where as previously if you put your foot down to hard I would get wheel spin and wheel hop. That has been eliminated with this upgrade. Third difference is you can confidently put the power down earlier coming out of roundabouts and also go around bends without having to lift off because it feels as the car is on rails. I had this fitted at Mountune HQ. With regards to the customer service at Mountune on the day, it has to be one of the best experiences I've ever had in the automotive industry and probably in general too. I was greeted as soon as I got out my car by Ryan who knew exactly who I was and what I was there for and he ran through everything clearly with me. I was well looked after during the 8-9 hour day I was there (has other work done as well), their waiting room has plenty to keep you occupied throughout the day. I would highly recommend having your Mountune upgrades fitted at their HQ if, like me, you aren't mechanically able and/or want to be assured of a professional service.