This has been the case for many decades - I once had to fit a Ford MKI Cortina engine to a MKII Cortina (port side not crossflow) and had to fit spacer washers between the engine and gearbox bellhousing to allow it to turn. Theoretically the same but it wasn't!

All 4 cylinder (excluding the V4's) Ford engines from the pre x-flow to the Mondeo/Mk 1 Focus Zetec used the exact same mounting bolt pattern. The Yamaha based Sigma engine and the Mazda based Duratec were different.

All Ford in line gearboxes from the 4 speed box used in the reverse window Anglia to the MT75 used in the last of the Sierras either had an integral bellhousing to fit this pattern or had a bellhousing to suit the 4 cylinder bolt pattern.

All these engine/gearbox combinations had one thing in common, a metal spacer plate/dust shield (call it what you like) that fitted between the engine and bellhousing.

Since the early 80's I have fitted many combinations of engines/gearboxes and never had an issue but I have always used the spacer plate. I have come across people in the Caterham community who haven't and some have been lucky and some not. When the crank is machined not all have the same length hole for the gearbox input shaft and equally not all input shafts are the exact same length. Get a long hole and a short shaft and it will be fine without the plate but get a short hole and a long shaft and it will 100% ground before the engine and bellhousing are fully tight without the plate.

2 examples. A friend of mine bought a Caterham fitted with a MT75 box onto a x-flow (not a factory option with Caterhams but it was with Westfields). After he had owned it for a while the engine went bang in a big way and he enlisted my help. When we stripped it the center main bearing had snapped out of the block and the crank was in 2 pieces. The car builder had not fitted a spacer plate and the result was a totally wrecked engine. New engine acquired, gearbox rebuilt (just in case it too had been stressed) and assembled with spacer plate and all OK. Another friend was fitting the engine and box together for the first time with no spacer plate and he did not gET as far as tightening all the bolts fully. One of the mounting lugs on the engine snapped off wrecking the block. Engine rebuilt and assembled with spacer plate and no issues.

Over the years many spacer plates were omitted after work by less experienced mechanics. They tended to fall out when the engine/box were split to fit a new clutch and were left where they fell. Most owners were lucky I guess.

How thick was the plate, about 3mm or the thickness of a couple of washers.

yes the plate is a couple/3mm.

i cant see the box's being that different to be honest, the net is covered with horror stories of failed auto boxes for my generation of santa fe, so i'm thinking the new box will be improved internals only.

after measuring both old and new with a digital ruler, they are the same depth from the bell housing to the bolt hole. either im cack at putting the TC in the gearboxes and both have not gone as far back as they should now, or i must of pulled it off to far when reattaching the flexplate. Im attaching my olf flexplate back and returning the £72 metal disk to hyundai. how they can charge that much for it i will never know.

Careful now - the net is full stories of failed Santa Fe gearboxes from the first year of US production sold only in North America - the specific fault affecting those gearboxes wasn't present in the Korea-built Santa Fe's sold in Europe.

As a keen member of both the UK and International forums covering Santa Fe, the issue was a non-event in Europe. The 6-speed automatic is fairly robust and generally trouble-free - particularly if the ATF is changed every 40-80,000 miles dependent on whether towing or not.

As this transmission wasn't right at 35,000 with "clonking" and nothing done 'till 80,000 the result was probly inevitable.

Edited by RT on 16/11/2018 at 15:44

As this transmission wasn't right at 35,000 with "clonking" and nothing done 'till 80,000 the result was probly inevitable

Only just realised. You bought a 2012 Santa Fe in 2016 with a "clonking" gearbox. It would still have had some of Hyundai's 5 year unlimited mileage warranty left so why on earth did you not take it for the garage to fix free of charge.

Bit late now, horse and stable door etc.

i never felt it myself, but the missus reported it several times to me. i wasnt sure what it was at the time.. lesson learned.

also, IIRC the warranty ran out ~3 months after buying it.