Installed 3.45 LSD today

[L84THSKY]

Hello All

Did the swap today. After getting the diff and half shafts out, we discovered a problem. The E30 flanges did not mate up with the E30 half shafts. Some how the year of the diff, did not match the year of the half shafts. So I said to my friend, " Looks like we gotta try plan B". It was time to test the E30 diff with the 318ti flange and half shaft theory. Will it work or not. I've heard so many stories about problems, and no problems. Here is what happened.

The diff was a pain to get in, but it fit just fine; no modifications period!
The 318ti half shafts and flanges fit fine with no problems. So as it stands, I have a 6 cylinder 3.45 LSD with 318ti flanges and half shafts. That was also with the M-coupe cover installed. I didn't tighten the drain plugs very tight, since I couldn't find the 14mm allen socket. I also need to torque the rear cover down to spec, when I get the correct value.

Took the car for a drive, and all is good.

I also put on the Mini rear muffler hangars;check the picture.

[FATHER]

good job, hey remember repair your spare tire

[L84THSKY]

What do you mean repair your spare tire? I just had to let the air out. I always carry an air compressor in my car anyway.

Originally Posted by FATHER

good job, hey remember repair your spare tire

[Couverman98682]

Looks nice and clean. Does it drive different since its from a 6 cylinder.

[SporTi]

I am new to the Ti world, but learning quickly. I assume from the rpm that my car spins that stock is 3.90? 4.10? I plan to go dasc eventually and have thought that with the extra power a lower diff might be in order. What was the source for the diff,and what is our normal ratio?

[GDB]

Originally Posted by SporTi

I am new to the Ti world, but learning quickly. I assume from the rpm that my car spins that stock is 3.90? 4.10? I plan to go dasc eventually and have thought that with the extra power a lower diff might be in order. What was the source for the diff,and what is our normal ratio?

Stock is 3.45 for the manuals and 4.44 for the autos.

As for changing out the diff, the cheapest way is to get one out of an E30 (previous generation 3 series) in the ratio of your choice.

[andyman7931]

so all you did was swap the ti flanges to the e30 diff... hmmm... maybe the 3.73 ls diff beckons me from the garage sooner than I thought!

let us know how it holds up over time.

[L84THSKY]

I don't notice anything different driving it. I now have a set of rebuilt halfshafts that cost me over $500.00 that I'm not using. Until if and when I get a supercharger, I probably won't need them. Now I must decide if I should find flanges to fit my halfshafts, or just exchange the halfshafts for ones that mate with my E30 flanges.

The halfshafts were ordered from Circle BMW, and I'm not sure I can return them or even exchange them. So the easiest thing would be to find flanges that mate.

What annoyed me was I was told that all the late model E30 flanges would fit all the halfshafts. I'm gonna take pics of the flanges and halfshafts so the mystery can be solved. I remember ordering the halfshafts to fit a 1991 E30, can't remember if it was a 325I or what. Not sure what year exactly the diff came from.

Another interesting thing was the speedo sensor. The E30 diff had a different style and connector type. I put the 318ti diff sensor in the E30 diff, and it works fine.

Originally Posted by Couverman98682

Looks nice and clean. Does it drive different since its from a 6 cylinder.

[cali-ti]

realoem shows the same flanges for ALL years of e30 325i. it also shows the same reman'd halfshaft part number (which makes sense), but i know for a fact that there are differences in the actual ones used on the cars (and showed and spoke of the differences i found in my posts and gallery pics). they changed from hex head bolts to torx bolts and they are different lengths, i'm assuming in response to the different thicknesses of the halfshafts where they bolt to the flanges. what's the part number of the flanges you bought? i bought brand new e30 flanges and had no issues with it bolting up to the e30 haflshafts except for the length of the bolts. i'll take a look at the pics when you post them up.

EDIT: and remember you did NOT get an e30 diff!

[stormos]

all i can say is "IT'S ABOUT TIME!!"

[andy]

Interesting - if you can post part numbers or the years of each of the pieces, that would be great. My '88 325 diff + '84 318i halfshafts definitely needed some help...eventually mated them to the ti hubs.

[L84THSKY]

Here are the details.

Halfshaft part# 33211226901

This crosses to:
E30 318i SEDAN
E30 318i CONVERTIBLE
E30 318is COUPE
E30 325i CONVERTIBLE
E30 325i COUPE
E30 325i SEDAN
E30 M3 COUPE
I remember ordering halfshafts for a 1991 325i.


Torx Bolts part# 33211227279
TORX SCREW M10X50 ? from 08/1990 onward

Halfshafts have a 10mm size bolt, as do the flanges.

The difference is in the spacing between adjacent holes.
Shaft = 53mm
Flange = 55mm

That was outside to outside of adjacent holes. I realize it's not true center to center, but it comes out the same when comparing equally.

So, I need to get flanges that mate with my halfshafts.

Interestingly enough, when I read what is written on the inside of the flange, it says on one edge "10" on another "376" and the third looks like "55".

Hard to be sure if it's "55" or "65" or "85". But if it's "55", that confirms what I measured.

So I need 53mm hole spacing.

Here are pics of the two mating faces.

Originally Posted by cali-ti

realoem shows the same flanges for ALL years of e30 325i. it also shows the same reman'd halfshaft part number (which makes sense), but i know for a fact that there are differences in the actual ones used on the cars (and showed and spoke of the differences i found in my posts and gallery pics). they changed from hex head bolts to torx bolts and they are different lengths, i'm assuming in response to the different thicknesses of the halfshafts where they bolt to the flanges. what's the part number of the flanges you bought? i bought brand new e30 flanges and had no issues with it bolting up to the e30 haflshafts except for the length of the bolts. i'll take a look at the pics when you post them up.

EDIT: and remember you did NOT get an e30 diff!

[jdehaan]

I'm about to put a 3.64 lsd onto my conversion TI. Its a modified E30 diff i guess that i bought off ebay rebuilt from metrix motorsports. I have no idea how im gonna do it, but it'll get done if its the last thing i do!

[L84THSKY]

Well, it was pretty straight forward. Just ignore all the people who steer you in the wrong direction.

Originally Posted by jdehaan

I'm about to put a 3.64 lsd onto my conversion TI. Its a modified E30 diff i guess that i bought off ebay rebuilt from metrix motorsports. I have no idea how im gonna do it, but it'll get done if its the last thing i do!

[cali-ti]

where were the e30 flanges sourced from?