Drive shaft/ diff question

[nl328i]

Hi guys,

I am about to pull the trigger on a z3 lsd to put in the s50 swapped e30. I want to ditch the e30 drive shaft and flex disc adapter from revshift (getting lots of vibration). I have a spare 95 m3 drive shaft here. Will that bolt up directly to a 2002 z3 diff? That would be swell. Zf transmission btw :)

Thanks for the input guys- just trying to work out the vibrations.

[nl328i]

I'm 99% sure the z3 torsen had a 6 bolt flange. If so, I think my 6 bolt 95 m3 drive shaft will work perfect. If not I believe I can just take the output flange from the e36 diff I had and pop that in, regardless of the fact that it is a torsen diff. Then it should all work.

Correct?

Summary: s50>zf>6 bolt 1995 m3 drive shaft> z3 torsen diff (with 6bolt flange)

[nl328i]

Also, does anyone have a writeup for the flange swap? Is it as easy as some would make it sound?

Any advice is appreciated guys :)

[nl328i]

Also, two more questions:
1. If I stick with an e30 diff and just swap over the output flange from an e36 diff what torque specs do I use?

2. If I go with the z3 diff and have to swap the e36 flange into it, what torque specs are used for that?

Thanks guys, sorry for all the questions.

[FredK]

Wow. You just increased your post count by 1.7% with this thread. Kudos! :p

If everything bolts together, great! But I bet you will have to swap diff input flanges even with the Z3 diff. The torque specs should be identical between the Z3/E36/E30 diff flanges. The driveshaft studs determine the torque you should put on the locknuts anyhow.

Swapping flanges is fairly easy. You need to torque down the nut down so there is a set amount of drag force which you can either get a cheap inch pound beam type torque wrench, or you can do it by feel. The nut takes a reasonable amount of torque, so you'll need to bolt on a counter holding bar to keep the flange stationary while torquing the nut down.

[nl328i]

Thanks Fred!

I was hoping that the 6 bolt flange and 6 bolt e36 drivehaft will work. We shall see.

So no issue with using the flange from a e36 LSD in a z3 torsen diff? I'm clueless as to how the internals all work haha.

[FredK]

As far as I know, the diff case/gears are the same, but the LS unit is what is different. So, the E36 flange *should* work, but it is possible the flange heights are different. I'm uncertain, though, and that might be something you're going to have to just try out.

[nrubenstein]

No, it will not work. I'm about 99% sure that the 6 bolt flanges were changed for some idiotic reason and are not compatible. I had this thought myself since I have a 47k mile 6 bolt shaft. Additionally, the E36 6-bolt driveshafts have no length adjustment. I don't know if that is a problem, but I would be surprised if the E30 length was *exactly* the same, vs. close enough for the splined adjuster to cover it.

[nl328i]

No, it will not work. I'm about 99% sure that the 6 bolt flanges were changed for some idiotic reason and are not compatible. I had this thought myself since I have a 47k mile 6 bolt shaft. Additionally, the E36 6-bolt driveshafts have no length adjustment. I don't know if that is a problem, but I would be surprised if the E30 length was *exactly* the same, vs. close enough for the splined adjuster to cover it.

So you're saying any e36 flange won't work in a e30 diff? Or are you specifically talking about the e36 flange in a Torsen from a z3?

I have heard many people say the flange from the e36 will work in a e30 diff. Am I wrong about that??

[Wanganstyle]

I'm 99% sure the z3 torsen had a 6 bolt flange. If so, I think my 6 bolt 95 m3 drive shaft will work perfect. If not I believe I can just take the output flange from the e36 diff I had and pop that in, regardless of the fact that it is a torsen diff. Then it should all work.

Correct?

Summary: s50>zf>6 bolt 1995 m3 drive shaft> z3 torsen diff (with 6bolt flange)

100% sure that Z3 torsen units built by BMW have 4 bolt flanges; I have 2 entire z3 torsen units here. I have installed 6 bolt flanges on e30/Z3 units custom ordered by customers.

No, it will not work. I'm about 99% sure that the 6 bolt flanges were changed for some idiotic reason and are not compatible. I had this thought myself since I have a 47k mile 6 bolt shaft. Additionally, the E36 6-bolt driveshafts have no length adjustment. I don't know if that is a problem, but I would be surprised if the E30 length was *exactly* the same, vs. close enough for the splined adjuster to cover it.

Incorrect.


The 6 bolt flange and 4 bolt flange units are often interchanged back and forth by e36 guys (often improperly).

188mm units direct interchange all flanges on the pinion side; slide slide slippery slide............ even a e46 non m 4 bolt threaded flange will slip right on.


Ive seen this interchange action destroy more than a few gearsets/pinion bearing sets when people have diy swapped flanges and overloaded.

The e36 driveshaft will need the e30 center bearing installed.

Torsen, open, clutch, viscous diff it does not matter at all- the ring and pinion standard for 188mm units is from late 70's till late 1990's- bmw used the same standard gear sets for them all.

Sent from my GT-N7100 using Tapatalk 2

[nl328i]

100% sure that Z3 torsen units built by BMW have 4 bolt flanges; I have 2 entire z3 torsen units here. I have installed 6 bolt flanges on e30/Z3 units custom ordered by customers.




Incorrect.


The 6 bolt flange and 4 bolt flange units are often interchanged back and forth by e36 guys (often improperly).

188mm units direct interchange all flanges on the pinion side; slide slide slippery slide............ even a e46 non m 4 bolt threaded flange will slip right on.


Ive seen this interchange action destroy more than a few gearsets/pinion bearing sets when people have diy swapped flanges and overloaded.

The e36 driveshaft will need the e30 center bearing installed.

Torsen, open, clutch, viscous diff it does not matter at all- the ring and pinion standard for 188mm units is from late 70's till late 1990's- bmw used the same standard gear sets for them all.

Sent from my GT-N7100 using Tapatalk 2

Great summary and Info. R3v is the bomb.com

Just a quick question for you- is the z 4 bolt flange the same as the e30 4 bolt flange? Meaning, if I grab a 328i manual 4 bolt shaft, will it bolt up directly to the zf tranny and the z3 4 bolt diff without having to do the swaping of flanges? That would be fantastic.

[FredK]

Just a quick question for you- is the z 4 bolt flange the same as the e30 4 bolt flange? Meaning, if I grab a 328i manual 4 bolt shaft, will it bolt up directly to the zf tranny and the z3 4 bolt diff without having to do the swaping of flanges? That would be fantastic.

Yes. I run a Z3 3.23 clutch-type LSD. It bolts directly up to a 328i manual 4 bolt driveshaft (or any E30/E36 4 bolt, for that matter).

[mtlbloodshot]

Im running a ZF310 with a E36 328 drive shaft to a Z3M Diff. Everything bolted up no problem. The flange is a 4 bolt on diff and 3 bolt on trans. Don't know if that helps

[nl328i]

I have confirmed that the lsd has a 6 bolt flange, so does that mean my 6 bolt e36 m3 shaft will be usable now without having to swap flanges? The news gets better and better

[Wanganstyle]

I have confirmed that the lsd has a 6 bolt flange, so does that mean my 6 bolt e36 m3 shaft will be usable now without having to swap flanges? The news gets better and better

measure the bolt pattern diameter; there are 2 patterns for 188mm.
see if it measures the same as your e36M 3.0 shaft, the 3.0 M3 should be a 96mm bolt pattern.

if its already been installed then somebody did the work for you, or you have a non-USA part that would be new to R3v

please post some photos and the part number if there is one.
also of the internal LSD spool inside