Questions about gearbox replace - MMT6 to MTX75.

[max89k]

Hello.

I've got an idea to replace unreliable MMT6 Gearbox to MTX75, and to install Quaife kit (all insiders) on it.
Does anyone has experience in it? What problems can I face during this operations?

[Gadgeroonie]

is the car a Noble ?

[max89k]

Yes, GTO 3R

[Hollowpockets]

Sorry bit confused, the MMT6 is the better of the two gearbox's and should already have the quaife lsd. Can't think why you would want to change to the 5 speed box?

[max89k]

I'm thinking about MTX75 with Quaife upgrade:
http://www.quaife.co.uk/shop/products/qke29z-1

Is it worthy?

[JBliss]

Depends what you are using the car for.

the 6 Speed (MMT6) once uprated is the better of the boxes imho.

[max89k]

The car is for trackday-use only.

[TuxMan]

So Max just to confirm you have a 3 R with a 6 speed box and you want to go back to a 5 speed ?
Well having had both they are both pretty good boxes but the 6 speed is the stronger of the two and a few of us have upgraded from a 5 to a 6 to allow us to run more power .

Tux

[andygtt]

For trackday work or fast road with high power you NEED to fit gearbox cooling... this is the main killer of box's.

The next upgrade is to fit steel bearings and quite a few of us have fitted shot peaned and polished stock internals.

Once you get to really high power (over 450ftlb) the box's are still considered a consumable item unfotunatelly, lots of theory's as to why and some options in the future for very high strength boxs being developed.

For a Noble it is considered that the 6 speed is stronger than the 5 speed, its due to the fact it has 2 shafts for the gears rather than the one in the 5 speed... this means the bearings are not as wide apart... both myself and Tuxman have spent a fortune changing our cars from a strengthened 5 speed to a strengthened 6 speed and we both run well over 600bhp and near 550ftlb for track work.

If you have not been breaking the box id say you are better off with strengthening what you have... Im not sure quaife internals are going to be stronger (as they are not rated to 500ftlb) and will cost a fortune.

[Lakelord]

A lot of the folks in the States fitted 5 spd boxes for track day purposes but not sure if they used the MTX75 tho? When my 5 spd broke, I did look at using a Quaife gearset but was put off by the reduction in top end and the fact that it would be high revving on motorway journeys etc which would become very tiresome very quickly. If you're going to use for track only, this probably won't be a problem for you but be aware that sourcing these boxes can be a challenge as Ford no longer produce them.

[JBliss]

I also changed from the 5 speed to a strengthened 6 speed and even though i have not increased the power yet, i can tell its worth the money.