So, we are now the ‘proud’ owners of a 3.89:1 Mark II Escort Differential, a Mark II Escort rear axle, and a Sierra gearbox. Not all of them have arrived yet as they’re being shipped from the four corners of the country. Well, three of ’em, anyhow.
There is, however, a fly in the oh so shiny ointment.
Rebecca was fitted with Marina front disks a long, long time ago. Indeed, when she was first put back on the road in 2001 despite the shonky condition of much of her bodywork back then, good brakes were one of my top priorities; and of the available choices at the time, the Marina front disks were the best option.
They’re more than adequate for the project; indeed, she stops better than some more modern cars I’ve driven. But the PCD (“pitch circle diameter” – essentially the spacing of the bolts that hold the wheels on) is different to that of the Ford back axle. They’re actually not standard for Marina either, having been machined to fit the Morris Minor – a PCD of 4×101.6mm (actually 4x4inches). The Ford axle’s half-shafts’ standard PCD is 4x108mm, which might not seem that much of a difference, but it’s much more than enough to be a significant problem.
Even the seemingly tiny difference of 100mm (the original Marina PCD) to 101.6 is enough to be dangerous.
Which leaves us with a number of options:
– Have a different PCD on the front and the rear (and thus ‘Minor PCD’ minilites at the front and ‘Ford PCD’ minilites at the rear).
– Obtain Marina front hubs and disks drilled to Ford PCD.
– Obtain Ford halfshafts and drums drilled to Morris PCD at the rear.
– Replace the front marina disk brakes with Ford disk brakes.
My preference is to go Ford PCD all around, because Ford wheels are easier to get hold of than the quirky Morris spacing.
So we’re waiting, again, to hear from several companies to get an answer. Of course, at the end of the day, having different PCDs on the front and the rear is not ideal, but could be a temporary solution. They’re so far different that it’d be actually impossible to put the wrong wheels on at any point. But it may just be time to accept that the old Marina issue front disks should be replaced with something more shiny, and a wee bit more modern.