Can't think of an external oil pump on a Transit or what model you are on about, do you mean the viscous fan coupling? The earlier Transits ie. 2.5 di were a l/h thread and the newer 2.4 duratorq a r/h thread,there is a special tool/spanner for removing them,you can't get a bearing for them, just replace the whole assy.
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Try fixfault.com to fix vans.