gearbox and diff swap

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whitey357
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Post Sat Aug 24, 2013 4:33 pm

Orite folks is it poss to run a 325i with a 318 diff and box? If so is it straight swap?
daimlerman
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Post Sat Aug 24, 2013 4:43 pm

Is the 318 an early M10 engine or a later M40 engine?
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whitey357
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Post Sun Aug 25, 2013 7:35 pm

The 325 is an 86 and 318an 89
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Post Mon Aug 26, 2013 12:46 am

An '89 will have an M40 engine,and the gear box will not fit the 6 cylinder engine.

The diff will probably be a 4:1,gives 65mph at 3000rpm in 5th,this will just about make first gear redundant.A better choice would be a 3:64,this gives 73mph at 3000rpm.

Be aware that E30 diffs come in two sizes,small and medium,(large were fitted to some E28 and most E32!)easy way to tell 'em apart is to count the bolts holding the rear cover on,small has six,medium has eight.
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