nath 134 Report post Posted April 4, 2023 Hi guys I have all the gear from an E36 M3 Evo to convert my Switch-Tronic Alpina 3.2 to factory spec manual. The trouble is, the M3 diff has a 6 bolt flange and a 3.15 open diff has a 4 bolt input. (Irony here is that a while ago I had the retrofitted 3.15 swapped for factory spec 3.46, which I will now have to change back). What is the best course of action for the install? I assume that all standard non-m diffs are 4 hole? cheers nath Quote Share this post Link to post Share on other sites
thorburn 121 Report post Posted April 4, 2023 I'm in the same boat with needing a 6 bolt driveshaft back half. The back half cv joint is the same as what a few other bmws use. One example is an e53 diesel. From memory it's just a little too long. Quote Share this post Link to post Share on other sites
Gaz 1062 Report post Posted April 5, 2023 I had my factory auto driveshaft shortened/lengthened (i cant remember now) to suit. I'll be selling it later this year when I install the full evo rear end. Quote Share this post Link to post Share on other sites
nath 134 Report post Posted April 5, 2023 5 hours ago, Gaz said: I had my factory auto driveshaft shortened/lengthened (i cant remember now) to suit. I'll be selling it later this year when I install the full evo rear end. Interesting.. wonder if that's what I should do behind the 420g Quote Share this post Link to post Share on other sites
nath 134 Report post Posted April 7, 2023 Seems that its only the forward portion is different length auto vs manual, so with appropriate balancing and condition checks I could mate the evo front to Switchtronic auto rear? Quote Share this post Link to post Share on other sites
wrs 120 Report post Posted April 11, 2023 I have the 420g and 3.46 LSD medium case diff modified by KBM. I've been spitting out driveshafts which shouldn't happen so wanted to try the M3 CV at the diff end. KBM supplied a M3 rear CV section of driveshaft and a 6 bolt flange from a 535 and gasket which replaces the original E36 medium case 4 bolt flange. Haven't fitted it yet as I want to check the alignment of the current driveshaft as something has to be wrong for the rear uni's to keep failing. The CV won't fear any better if the alignment is wrong... So, a 535 diff flange fits the E36 medium case diff and bolts up to the M3 Evo driveshaft rear CV. To fit everything I'll need a custom driveshaft but should be able to use the existing front section with the 420g connection and front of the rear section with the M3 Evo rear welded just behind the hangar bearing. Quote Share this post Link to post Share on other sites