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Ford MMT6 Gearbox Transmission Service and Upgrade

Ford MMT6 Gearbox Service & Upgrade Ford (6000-GL-AA) | Mountune

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Availability: Turnaround time is usually 7-10 days. Contact us for more information.
Product Code: 6000-GL-AA

Vehicle Model*:
Focus RS [Add $165.00]
Focus ST

Add Differential to Service*:
Yes, Focus RS Quaife ATB Differential [Add $949.00]
Yes, Focus ST Quaife ATB Differential [Add $899.00]
No Thanks

Add Mountune Quick Shift*:
Yes, Add Mountune Quick Shift [Add $229.00]
No Thanks

Add Surface Treatment*:
Yes, Add WPC Surface Treatment [Add $650.00]
No Thanks

Add Shipping Option*:
No Shipping required, I will deliver.
Yes, Add Shipping Option [Add $199.00]

Description FAQs
Having issues shifting smoothly through the gears?

Mountune offers a complete Ford MMT6 Gearbox service and upgrade for Focus ST (2013-2018) and Focus RS (2016-2018).

Your gearbox will undergo a full teardown where each component will receive a motorsport grade cleaning prior to being inspected by our experienced professionals.

The fragile standard synchros are then replaced with our carbon lined heavy duty components along with all new upgraded bearings to ensure accurate selection when going through the gears–even under hard acceleration.

To get the maximum performance out of your Focus ST/RS MMT6 gearbox we would highly recommend adding the optional WPC gear and shaft treatment and Quaife ATB Differential upgrade prior to reassembly.

For more information about our MMT6 gearbox Service and Upgrade see the FAQ's Section Tab at the top of the page.

Recommended product
MOTUL MULTI DCTF - Dual Clutch Transmission Fluid (1L)


Average Rating: Average Rating: 5 of 5 5 of 5 Total Reviews: 5 Write a review »

  0 of 0 people found the following review helpful:
5 of 5 Tragedies and triumphs October 20, 2022
Reviewer: Josh Browning from Pleasantville, OH United States  
I sent in a transmission after 56k miles of abuse and torment. After cracking it open mountune realozed she was a lost cause, nearly every part woukd need replaced inside the case. So, we just went ahead and replaced it with the stage 1 conplete transmission. It is together and awaiting balljoints and an alignment and Ill be able to drive it and see how it feels.

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  1 of 1 people found the following review helpful:
5 of 5 Excellent Upgrade! June 18, 2021
Reviewer: Michael Kulp from College Point, NY United States  
So.. After installing Mountune's long block with Darton sleeves, lightweight steel crank/flywheel and head with v3 cams, my 3rd and 4th gear synchros said no. Mountune sends a crate for my tranny and I have them do their upgrade with WPC treatment and Quaife differential.

One word: Transformational.

The tranny shifts perfect and with the Quaife upgrade, it is now a noticeably more controllable serious performance car. In my opinion, you get what you pay for with Mountune, every part I've ordered from them has been exceptional in quality. If you're looking for a top notch installer in the NY Metro area, look up Precision Auto Works in Long Island City. The owner, Mike did all of my work and I couldn't be happier - he's a seriously talented technician. I'm 60, this car makes me laugh like I'm 18...

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  1 of 1 people found the following review helpful:
5 of 5 Super smooth and quick shifting October 23, 2020
Reviewer: David Davis from Spring Valley, CA United States  

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  2 of 2 people found the following review helpful:
5 of 5 Grips and Shifts August 10, 2020
Reviewer: Jason Offord from Fairport, NY United States  
The process for shipping and returning the transmission is well thought out and pretty easy, other than lugging 130lb to FedEx.  The new diff definitely grips hard and pulls through the corners.  Straightline stability has improved.  The only thing I would have appreciated was more feedback from Mountune about the progress of the work being done.  What step are you on?  What was the condition of the trans when it was disassembled?  Other than that I'm very pleased with my purchase and the quality of the work done.

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  1 of 1 people found the following review helpful:
5 of 5 perfect fit stopped problem May 31, 2019
Reviewer: Charles Anson from Bradenton, FL United States  
Let's say 4.5 stars, Mountune shipping option on this takes 10 days each way, not the 4 or 5 they try to sell you.  That being said, I just put the first 300 miles on it today, it feels awesome.  I've got all the bolt-ons, ford performance tune, stock turbo, south bend stage 4 clutch, short throw and short shifter arm.  I've puked 3 sets of synchros in the last year.  Albeit it was 30,000 miles in that year.  Ford did their part, they could only replace the transmission, they warrantied it 2 times.  The last time lasted 2 weeks with me going easy on it.  I couldn't believe it.  Mountune thinks it looked more like a refurbished tranny.  They found one bearing .012 too tight!  Anyway, I got the whole treatment, WPC, new synchros, they cleaned the thing completely out, including the LSD I already had.  I'll report back every 6 months or so.  I'm praying this works, but so far so good I would say.  The shipping was the only slow part, the work did not take long.

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