Will 1986 318i diff fit in 1989 320i and anyidea of ratio?

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Hazar320
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Post Thu Jul 31, 2014 12:36 pm

Ive got a 320i which i belive has a asc or asc diff in it but it wines like hell, i also have a 318 i am using for parts which i belivehas a good diff in it.... So is it an easy straight swap? Any idea if i can take the diff out using a jack n stands? Cheers!
daimlerman
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Post Thu Jul 31, 2014 12:52 pm

All E30 diffs are interchangable,although some require an adjustment of the propshaft length.This is easy,just involves slackening the collar nut at the join of the two halfs and sliding the rear half forward.

However,assuming you have a manual 320i,this should have a 4:1 ratio,the 318i,if also manual,will probably have a 4:27 ratio...

You will need room under the rear of the car,dis-connect all three shafts(prop and both driveshafts!)un-plug the speedo sensor,support the diff,un-bolt the rear mount and all four top bolts.
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HairyScreech
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Post Thu Jul 31, 2014 12:53 pm

If they are both E30s then yes the diffs will swap with no issues.

a 320 and 318 should have roughly the same ratio diff, certainly close enough to not matter in this circumstance.
2.8 development thread http://www.e30zone.net/modules.php?name ... c&t=170822

m3.3.1 m20 thread - now running, chip needed - any volunteers?
http://www.e30zone.net/modules.php?name ... =viewtopic&
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Hazar320
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Post Thu Jul 31, 2014 4:17 pm

Thats brilliant! Much appriciated, ill let you know how i get on :)
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Hazar320
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Post Tue Aug 05, 2014 8:58 am

Diffs in! No noises which is a relif. However, the starter motor has now decided it doen't want to work... I know the engine is totally different but any idea if the 1986 starter will fit? Cheers
Grrrmachine
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Post Tue Aug 05, 2014 9:02 am

Starter not working does not mean the starter is at fault. And no, a 318i starter won't work on a 320i, they're completely different engines.

If the starter won't spin, perform the Diagnostic Plug start described on this page, and proceed from there:

http://www.e30zone.net/e30zonewiki/inde ... oubleshoot