RWD Automatic Zetec conversion.

Here I will document my Automatic RWD Zetec conversion it is not a guide nor advice, just a record of how I converted a FWD zetec engine to a RWD Automatic with a few extras I learnt along the way thrown in.


Engine:

I’m using a 2.0 blacktop zetec from a 1999 Mondeo with a Ford focus EFI and ECU from 2001 and a Ford C3 Automatic Transmission from a 1975 2.3 Mustang.

Donor Engine

To RWD convert this it has a Sierra sump and oil pickup fitted.
In theory I should be looking at around 143bhp and 140lb-ft of torque.

I’ve opted for the retro ford alternator kit and will be using their DIY mount kit aswell.

As space isn’t an issue in my application I’m using the original thermostat housing so no need for a water rail.

Transmission:

I’m using a Ford C3 Automatic Transmission originally from a 2.3 Mustang with a Mondeo automatic flexplate (135 tooth, 11.3″) and Mondeo automatic crank sensor. The A4LD box was also an option but I wanted the simplicity of the C3 transmission.

I had a local engineering firm drill the TC mounting holes in the flexplate using a lathe to get them spot on.

There are at least 3 bellhousings for the C3 box which will fit on the zetec and all these need the smaller 3 bolt torque converter as the 4 bolt version fouls on the zetec timing gear.

2.3 Mustang bellhousing bolts straight up to the zetec but requires the correct Mustang starter (1974-1985)  or an adapter for the sierra starter and the smaller British TC.

1.6 Crossflow bellhousing (Escort etc) this bellhousing requires the smaller TC and a Sierra DOHC starter but as it’s considerably deeper than the pinto one you will also need a spacer between the TC and flexplate (approx 10mm), the starter is on the opposite side to the others.

2.0 Pinto bellhousing (Cortina etc)
Although I’ve not tested this myself I’m told it’s the same depth as the Mustang one so should bolt straight up using the smaller TC and the sierra DOHC starter.

When originally fitting the Torque Converter I didn’t have it seated properly, A tip given to me was to smear a line of grease on the rear end of the TC that way you can ensure its fully located as after removal you can see how far the rear seal came up the TC!

2.3 C3 Transmission with 3 bolt TC and Mondeo Flexplate

The Automatic flexplate bolts are different to the manual flywheel ones and have been discontinued by ford, luckily retro ford had some in stock. They are a class 10.9, M11 X 1.0 pitch bolt, the thread is 15mm long with a 2mm shank, they have an 18mm hex head which is 6mm tall.

Automatic Zetec Flywheel bolt

Starter motor spacer:
Whatever the transmission you’ll need to space your starter so it engages and disengages properly with the Mondeo flexplate.

With a sierra starter I found a 10mm spacer was needed and the same with the Mustang however I made an adapter plate so I could fit a sierra starter on instead of the OG Mustang one.

The flexplate teeth sit approximately 8-18mm from the sandwich plate.

Starter motor adapter

 

Complete engine fitted

Hopefully this helps someone and I’ll try and finish the write up at some point.

Thankyou Neil for all your help and encouragement along the way.

2 thoughts on “RWD Automatic Zetec conversion.

  1. Hi,

    I don’t know how old this information is or, the last time this website was updated. But, I’m fascinated to know how you’re getting on with it.

    I intend to mate a 2.0L Sivertop to a 2.0L Sierra auto, it’s from the DOHC Sierra. I have most of the parts and indend to start putting it together soon.

    Colin

    1. I only published this this week,. currently my engine is in and running with just the shifter and wiring to finish up!

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