I was needing input on a 1945 ford truck rearend. I am puttig together a 27 T roadster and had aquired a 39 rear for it and was going to convert it to open drive line then I got a 45 truck rearend given to me yesterday which is already open type with a drive shaft to boot. My question is will the guts of the 45 rear fit in my 39 rearend ? the reason I ask is the 39 rear is in better shape and already been reworked to fit the 27. The 45 rear is a little wider and the axle tubes are noticeably beefier can I mix and match any of these parts to make my 39 rear into a open driveline setup? or am I stuck with buying the open driveline conversion for my 39 rear.
you need to use the axles and the spider gears from inside the differential and the axle tubes from the 39. put the 39 spiders and axles in the 45 diff. then use the whole 45 center section. i just did this swap 4 weeks ago. bearings, races and seals aren't a bad idea while you have it apart. piece of cake.
Count teeth on axles and spiders...I think they changed in 1938, so 1939 should be the same as the later ones. If the same, go with the parts that are in better shape. Differential inner case is same, there are two tooth count types for spiders and axle ends. And if it matters, the length of axle used in '39 exists in both tooth types.
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