Diff ratio's and gearbox identification

[DutchWestfield]

Hello,

After ordering my kit last saterday I am now searching for the right bits for my Westfield. Although the manual has a lot of details on this, I am not entirely sure yet.

Concerning the Diff:

  I decided on a 3.92 diff. The manual says one can find the 3.92 in several Sierra's. I assume that the different Sierra models have their own ratio ?? I have noticed that the manual states the different ID numbers that Ford uses, but i don't want the scrappie to lift up 10 cars before I find the right one.... I there any logic in which ratio sits in which Sierra (or Scorpio) ?

Concerning the gearbox:

  I decided on a MT75 gearbox. Again the manual states that the Type 9 and the MT75 can be found in Sierras. Again, I don't want to get home to find out I have bought a Type 9 or something else I can't use... I know I should get a gearbox from a non-DOHC Sierra, since this has a hydraulic clutch actuation. But how do I disthinguish a Type 9 from a MT75. Am I right that the Type 9 is ally, while the MT75 is cast iron ??

Just to make you less concerned, I am pretty sure about the lobro joints (the ones with bolts in them) and the brake calippers (I hope I can find some Cortina calippers at the scrappie...)

Any help is much appriciated,

Bertram

The Netherlands

[Westfieldman]

Change your mind you would be better with a T9 gear box

The important thing with a Diff is you get one from a XR4x4 this is a 3.62 and be LSD. then have the ratio changed and the bearings checked/replaced

The type 9 gearbox is a better gearbox and ratios cheaper easier to get for your car. But the tunnel is different

If you are going for a Zetec you would be as well having an MT75 tunnell and a type 9 mounting this put the engine, bellhousing as far back in the car as it will go so a better balanced car.

While at the scrapies if you can find the XR4x4 you can get the outer shafts [Westfield part number 3213014 & 321013] brake callipers and mounting brackets from this car Westfields rear disc kit part number 2340026 buy the discs from Westfields as they are cheap hand brake lever can be had from the same carand the gaitor

New lobo joint can be had from a local motor factor.

Paul.

[jamie]

Hi Bertram

No you have the type 9 and the mt75 wrong! the mt 75 is the ally one found in the dohc sierra and the type 9 is the cast iron one found in earlier sierra and cortina  

The right one for you is you problem but you will have to have the right chassis for the mt75 as it is a bigger unit than the type 9 as it has a moulded bell housing and you are limited to engine type i.e. ztech, dohc not to sure on the x flow? (Blatman will know)    

The mt75 is a good gearbox and I have seen 350bhp put thought this unit

But as discussed it think the mt75 is a more expensive unit to exchange gear ratios etc.

All the best

Jamie

[Blatman]

you are limited to engine type i.e. ztech, dohc not to sure on the x flow? (Blatman will know)

I'm not sure..........  

I'm thinking that if both type 9's and MT75's have been fitted to Zetecs, then the bellhousing pattern is the same (for a x-flow) anyway, so it doesn't matter.

I'm also thinking that the MT75 has a non removable bellhousing. The type 9 bellhousing can be removed (and should be removed, and replaced with an ally RS2000 bellhousing, to save a load of weight........).

The type 9 has far more choice when it comes to changing ratios for a more appropriate set. I don't recall ever seeing replacement ratios for an MT75.

If you are going for a Zetec you would be as well having an MT75 tunnell and a type 9 mounting this put the engine, bellhousing as far back in the car as it will go so a better balanced car.

Paul is spot on. Get the type 9, and shove it right up inside the tunnel, to get the weight distribution improved.

My car has an MT75 tunnel housing a type 9 box. See how far back

my engine sits................

[Fast Westie]

Paul is spot on. Get the type 9, and shove it right up inside the tunnel, to get the weight distribution improved.

My car has an MT75 tunnel housing a type 9 box. See how far back

my engine sits................

I wondered how you did that

You can get new ratios for the MT75 at about £2000 a set  

[Westfieldman]

What do they do for that money file them up by hand.

Paul.