E30/36 LSD into E46 Swap

subbed! looks good to me, best of luck

Looks good so far. I'm interested to see where this ends up.

i was going to wait to see if this would be a viable alternative to the e46m swap , but couldnt pass up a local deal on one....

best of luck aggie

I picked up a tool to pull the bearings. I'm going to have to modify it. It's too fat to do the job. Time to pull out the grinder.

Would you mind posting the cost of each step? I understand once you have broke the ground. It will be cheaper for the next guy. However, it would be nice to see what this is costs vs a ready available lsd.

Yep, I'll totally put up what I pay. Don't mind at all. I want everyone to see if this is worth doing for them.

Originally Posted by xixixi

Would you mind posting the cost of each step? I understand once you have broke the ground. It will be cheaper for the next guy. However, it would be nice to see what this is costs vs a ready available lsd.

since you are trashing the bearings and going with the e30 ones can't you just take a die grinder/dremmel cutoff to it?

Im in for the results.

I am still going to try to save them. I found a "source", but they're $75/set for used bearings.

Also, I found that E90 sealed ball bearings are a direct swap, too. But they take "budget" out of budget LSD.

Originally Posted by SL Blak Soldier

since you are trashing the bearings and going with the e30 ones can't you just take a die grinder/dremmel cutoff to it?

Got 3/4 of my bearings off. Messed up the old ones. I salved the easy E46 bearing. Working on getting the other one off. Gotta run to Home Depot at noon and buy longer bolts for the tool.

Edit: Got the 4th bearing off. Trashed. So, I have one good bearing. I'll probably go ahead and just buy 2 to have a backup.

I used this tool:

http://www.harborfreight.com/bearing...set-93980.html

I had to grind the lips a bit to get a bite and I had to get longer bolts to get the last bearing. For $40, it's nice to have the tool, but I may never need to use it again. If you want to save some hassle, talk to your machine shop about just pulling these off. Might even be able to save yours.

So, here's where we are:



As you can see from the picture, the units themselves seem to be the same height. I haven't measured, but they're pretty darn close. So to add to my excellent illustrations, here's what I'm supposed to do next. The LSD must be modified so that the ring gear is in the same position as it is on the open differential. As you can see, it's too long. I will need to have the bearing seat and shoulder milled down so that it matches. That's the next step.

I'll get ahead of myself and say that after that, the unit itself will be too short. I will then have to have a spacer made to space the bolt-on cover out towards the driver's side. That will make the LSD unit the exact length of the open unit and put the ring gear in the same position as it is on the open unit.

Enjoy the update!

The e30/36 bearings will come off perfectly cleanly and unmarred with the correct tools. Minimal force required also. Zen approach style.

Are you using a 168mm or 188mm LSD unit?

The e46 cases are narrow compared to the earlier units, the ring gear is more centered for bearing load-
To fit a 188mm earlier chassis diff into the e46 case requires clearance-ing the case. Aftermarket LSD installation (OSGIKEN,Kaaz) requires minor grinding, installing a Oem earlier car standard unit is more than minor grinding. Older lsd 188mm units have almost no clearance in a e46 case. Replacement parts for these diffs are avail from ZF engineering in Germany, parts are very expensive.

The spacing gap difference between flange geometry also needs to be made up. If using a 168mm unit then the bolt pattern/count as well.

In the end of the day it's adapt-able yes and some builders do it. I prefer doing a OSG or Kaaz install keeping 188mm or going to the 210mm e46m diff unit. 3.07, 3.15, 3.23, 3.46, 3.62, 3.91, 4.10 and ++ are all avail in 210mm standard. Two bolt patterns of hardware create some expensive compatibility solutions.


If you are dead set on retroffiting an older Lsd center to newer case
I'd suggest starting with the 168mm unit as more clearance will be your friend, A spacer is needed regardless. Good luck on the mounting fasteners!

Building up an Oem bmw LSD is required as dumping a ancient rotting smelly 20 year old LSD into your prepped grippy tire e46 is probably not going to be a long lasting solution, e30's can easily wear out their stock LSD units. Refresh and rebuilding the internals of the LSD unit is a cool $250 in just parts. Add that to the core unit cost+ labor and perhaps a brand new quaife LSD is not such a bad deal after all. Kaaz is not a very street friendly or economical diff, I just removed one from my own car.

I don't really claim to know what I'm doing. Where is the 168/188mm measured?

There shouldn't be any grinding of the case required, but I can't be 100% sure of that until I'm finished.

I don't track my car. I just drive it spiritedly. If the unit doesn't hold up, I've done something more enjoyable and had more of a learning experience than wrapping my interior with Dinoc....

Sounds like you have some experience with where I'm going. Please keep an eye on the thread and let me know what you think.

Originally Posted by wanganstyle

Are you using a 168mm or 188mm LSD unit?

Subbed!

Brady, this should definitely be a viable option for non-Ms.

The M3 LSD is so useless with a 3.62. When I repair my subframe this summer, I'll be shooting for a 3.23 LSD, so hopefully this gains some great momentum in the near future!

Originally Posted by Hornung418

The M3 LSD is so useless with a 3.62. When I repair my subframe this summer, I'll be shooting for a 3.23 LSD, so hopefully this gains some great momentum in the near future!

It's definitely not useless, especially with a 6th gear

Good progress Brady!

Originally Posted by tinkwithanr

It's definitely not useless, especially with a 6th gear

+2. At 2900 RPM @ 70 MPH I need a 7th gear or an M3 engine to match

LSD is awesome though...don't think I'll ever buy another one wheel wonder if I can avoid it.

Originally Posted by aggieE46

Got 3/4 of my bearings off. Messed up the old ones. I salved the easy E46 bearing. Working on getting the other one off. Gotta run to Home Depot at noon and buy longer bolts for the tool.

Edit: Got the 4th bearing off. Trashed. So, I have one good bearing. I'll probably go ahead and just buy 2 to have a backup.

I used this tool:

[url]http://www.harborfreight.com/bearing-separator-and-puller-set-93980.html[/ul]

I had to grind the lips a bit to get a bite and I had to get longer bolts to get the last bearing. For $40, it's nice to have the tool, but I may never need to use it again. If you want to save some hassle, talk to your machine shop about just pulling these off. Might even be able to save yours.

So, here's where we are:

[IMG]http://i.imgur.com/oxIMG.jpg[/MG]

As you can see from the picture, the units themselves seem to be the same height. I haven't measured, but they're pretty darn close. So to add to my excellent illustrations, here's what I'm supposed to do next. The LSD must be modified so that the ring gear is in the same position as it is on the open differential. As you can see, it's too long. I will need to have the bearing seat and shoulder milled down so that it matches. That's the next step.

I'll get ahead of myself and say that after that, the unit itself will be too short. I will then have to have a spacer made to space the bolt-on cover out towards the driver's side. That will make the LSD unit the exact length of the open unit and put the ring gear in the same position as it is on the open unit.

Enjoy the update!

Okay, so I'm trying to figure this out in my head. Help me out a bit.

You are going to mill where the bearing seats to allow for the ring gear to seat correctly (as it's pictured you want it to go down??)?

If that is it, can't you get a spacer made where the ring gear sits to push it over (down, as the picture is orientated?). So that the "flange to end" to be the same height? That way you'll wind up with the correct length and wouldn't need to space out the bolt-on cover?

Originally Posted by tinkwithanr

It's definitely not useless, especially with a 6th gear

Good progress Brady!

No, it definitely is ridiculous to put a 3.62 in the rear on a car that has a 6500rpm red line. Even if you bump it up to 7000rpm you're still doing a measly 85 miles per hour at the top of 3rd. Better to keep the ratio low and add an LSD than to sacrifice MPG, top speed and cruising speed. I know for a fact that I don't need to be turning 3600rpm doing 74mph on the high ways.

I'm running a 3.64 LSD with my 6-spd (and 7k rpm red line) and love it. 70 mph is just under 3k rpm and even 85 is only ~ 3500 rpm, doesn't bother me or the wife at all. I'll admit that I never would have gone so short had I not had a unique opportunity to borrow a 3.64 for over a month prior to upgrading my own. After a road trip from Dallas to Austin, I knew I was completely comfortable with it. I'd definitely never run that ratio with a 5-spd though. I'd probably not run such a short ratio if I had a really loud exhaust either.

Would the 3.15 LSD from an e39 perhaps fit easier ?

Originally Posted by aggieE46

I don't really claim to know what I'm doing. Where is the 168/188mm measured?

There shouldn't be any grinding of the case required, but I can't be 100% sure of that until I'm finished.

I don't track my car. I just drive it spiritedly. If the unit doesn't hold up, I've done something more enjoyable and had more of a learning experience than wrapping my interior with Dinoc....

Sounds like you have some experience with where I'm going. Please keep an eye on the thread and let me know what you think.

I have a empty e46 non m case here, I had it clearanced to fit a 188mm LSD center. I can email you a photo if the clearancing required to fit if you really want to know. It's a decent amount. With a ring gear attached and no spacer to adjust the centerline, it still needed clearance of the case. This was a side project to building up a nice os giken aftermarket unit for e46non-m. Took some spares off the shelf and tried to play the retro fit game. I change diff bearings and set ring /pinion gaps for diff builds, so it doesn't scare me.

The e46 cast housing is designed to clearance open diffs for installation.

if you mess with the spacing bolt on top cap of the e36/30 LSD center capsule the spider gear will also need a spacer. This opens up another very expensive/time consuming can of worms. My suggestion? Don't go there.

Perhaps adapting the e30 bearings and races and spacing would be smarter.
The e30/36 stub axels use a different standard e46, the circlip position is different, geometry also. Will the dust shields all line up post if Frankenstein-diffed?

Originally Posted by Hornung418

Subbed!

Brady, this should definitely be a viable option for non-Ms.

The M3 LSD is so useless with a 3.62. When I repair my subframe this summer, I'll be shooting for a 3.23 LSD, so hopefully this gains some great momentum in the near future!

The e46m unit can be re geared with Oem m division ring and pinion to 3.23 and 3.15 ratio. LSD center can be clutch type or gin visco-lok. I just built one up for turbo use (3.15 e46m clutch LSD diff). This would allow non m cars to Pnp a LSD in matching ratio to a 6500 rpm engine with a m3 rear subframe swap.

The e46m rear diff can be configured with genuine BMW parts to have a 4 bolt front flange that will mate with non m 4 bolt driveshaft 4 bolt pattern, this would allow upgrade of e46m of diff without buying a zhp 6 bolt driveshaft

Also the late model 2005/6 325ci/cabrio 6 speed SMG cars have a 4 bolt driveshaft in 6 speed length, they run a ZF 6 speed gearbox with identical length and mounting position in the body to the e46m gearbox.