Just got an LSD, have a question

[mech9T8]

I need to swap the input flange because the LSD is 6 holes and current one is 4. I've seen the DIY for the switch but wondering if anyone has done it and has some tips.
I've also read that input flanges should never be removed?

[Boots R]

Are you using a 6-hole m3 driveshaft as well?

FYI: 4-hole regular driveshafts will mount up to 6-hole m3 input shafts, as far as I can remember.

[mech9T8]

Using my stock drive shaft (4 hole).
I don't think 4 hole will bolt up to 6 hole (geometry doesn't work).

[ScotcH]

This is not really something for a diy without proper tools ... you need to set the torque just right or something ... preload on the gears, whatever. I'd have a shop do it, or just pick up a 6 bolt driveshaft (Fil probably has one for cheaper than a shop will charge you).

[bmdbley'sBro]

Originally Posted by ScotcH

This is not really something for a diy without proper tools ... you need to set the torque just right or something ... preload on the gears, whatever. I'd have a shop do it, or just pick up a 6 bolt driveshaft (Fil probably has one for cheaper than a shop will charge you).

is Fil a local (driveshaft-diff) guy? cause i have the whole rear subframe from a 325i 4door w/lsd kick'n around..
I want to get that lsd in my 318is

I'm told i'll more then likely i'll need the back half of the 325i'd drive shaft with the front part of my 318is's shaft..
something about different lengths

[propr'one]

Its not difficult to do, i watched rocco do mine, however, like scotch said, it will take you an hour to do properly if you've never done it before, a mechanic can do it in 5-10 mins.

I would definatly not swap the driveshaft, its overkill, having a shop swap the input shaft is real easy, and they can use the one off your stock diff.

[999666]

Originally Posted by bmdbley'sBro

is Fil a local (driveshaft-diff) guy? cause i have the whole rear subframe from a 325i 4door w/lsd kick'n around..
I want to get that lsd in my 318is

I'm told i'll more then likely i'll need the back half of the 325i'd drive shaft with the front part of my 318is's shaft..
something about different lengths

Different subject, but you are right for your application.

Input shaft for the 4 bolt 325 and 6 bolt 328/M3 is the same leghnth just different bolt pattern, unlike it is for you putting a 318 D-shaft on a type 188 diff your looking to make up the difference in diff sizes.

Do not listen to the counter productive/negative ones who say " YOU CAN'T DO THAT" it really is simple as you have described in your first post, impact it off, swap them, saturate it in alot of gear oil, seat it in the new M3 diff, snug it then turn the shaft inside the diff to be sure it's seated well, then inpact it back on & install it on the car.

[98Dinan3]

Originally Posted by ScotcH

This is not really something for a diy without proper tools ... you need to set the torque just right or something ... preload on the gears, whatever. I'd have a shop do it, or just pick up a 6 bolt driveshaft (Fil probably has one for cheaper than a shop will charge you).

That's right.... there is a crush washer on the input flange that applies the correct pressure on the diff internals. Too tight and it'll bind, too loose and you'll have too much lash in the gears. It's not worth risking an LSD on the DIY. Just take it somewhere reputable... shouldn't cost much if you've got both diffs out of the car.

[mech9T8]

I've seen torque specs for the nut on the input flange.
And people also say to mark nut/bolt with paint mark so you know you won't overtighten. Won't this work?