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DISCUSSION => Engine + Driveline => Topic started by: dakar318 on December 19, 2008, 06:41:09 PM

Title: M3 diff. into a 318is
Post by: dakar318 on December 19, 2008, 06:41:09 PM
ok i have a E36 m3 3.23 i want to put in my E36 318.

the drive shaft flange is the same, but the axles are different.

do i need to run m3 axles?

are the hubs different?

would i need a whole subframe?
Title: M3 diff. into a 318is
Post by: E30tii on December 19, 2008, 07:07:01 PM
Doesn't the M3 have a 4.10 diff?

Or is this an E36?
Title: M3 diff. into a 318is
Post by: dakar318 on December 19, 2008, 07:08:43 PM
whoops this is an e36
Title: M3 diff. into a 318is
Post by: Deftones on December 20, 2008, 11:23:36 AM
you need m3 axles, and all the M3 suspensions! and because the brakes is fixed on a suspension brace, you need disk and calipers too!
Title: M3 diff. into a 318is
Post by: szed03 on December 21, 2008, 07:07:59 PM
Quote from: Deftones;63271
you need m3 axles, and all the M3 suspensions! and because the brakes is fixed on a suspension brace, you need disk and calipers too!

Sorry to say it but that's dead wrong.

You won't need M3 axles if you can get the diff output flanges from a non-M 6cyl diff (325/328).  It's easy to remove and install; a pry bar or screw driver works fine.  That way you can use the non-M axles which won't require a new wheel bearing and hub.  I believe the splined section of the M3 axles are larger in diameter necessitating a new hub.

You will need a 325 driveshaft if you don't already have one.  You can get away with using just the rear section of the driveshaft as the length of the first half are the same between the 318 and 325.  Let me know if you need one, I have a spare.

No need for an M3 subframe either.  Same mounting locations.

I'll be doing a diff swap myself really soon as well.  Going with a 3.91lsd from a 325.

Oh yea, and why are you putting a 3.23 in the 318?  It's going to be REALLY slow, considering that the stock ratio is 3.45.  Unless there's something you're not mentioning to us...like a massive turbo. :)
Title: M3 diff. into a 318is
Post by: Deftones on December 22, 2008, 02:26:04 PM
Quote from: szed03;63335
Sorry to say it but that's dead wrong.

You won't need M3 axles if you can get the diff output flanges from a non-M 6cyl diff (325/328).  It's easy to remove and install; a pry bar or screw driver works fine.  That way you can use the non-M axles which won't require a new wheel bearing and hub.  I believe the splined section of the M3 axles are larger in diameter necessitating a new hub.

You will need a 325 driveshaft if you don't already have one.  You can get away with using just the rear section of the driveshaft as the length of the first half are the same between the 318 and 325.  Let me know if you need one, I have a spare.

No need for an M3 subframe either.  Same mounting locations.

I'll be doing a diff swap myself really soon as well.  Going with a 3.91lsd from a 325.

Oh yea, and why are you putting a 3.23 in the 318?  It's going to be REALLY slow, considering that the stock ratio is 3.45.  Unless there's something you're not mentioning to us...like a massive turbo. :)


ops sorry i think i mistook cause i'm used to talk about euro M3! (i had got one and i modified the LSD to 25% to 90% so i know it well)... Euro M3 are different from others 6 cyl for what concerning axles, output flanges and suspensions braces, in fact my friend with a 320i changed all this parts to fit an M3 diff in his car, and now he runs with complete M3 brake set.
However, reading from internet, it seems to be that usa M3 are more similar to a powered 328 than euro M3! so it is logical to think that also differential is the same of a common 6cyl with lsd
Title: M3 diff. into a 318is
Post by: szed03 on December 22, 2008, 04:48:32 PM
Ahhh yes, the euro e36 M3s used the large-case 210mm diffs correct?
Title: M3 diff. into a 318is
Post by: Deftones on December 23, 2008, 04:51:36 AM
Quote from: szed03;63396
Ahhh yes, the euro e36 M3s used the large-case 210mm diffs correct?


yes that's right;)