DIY: How To Swap a Differential (plenty of pics)

[328 Power 04]

oh ok ...hmmm didn't read that, cool

[JETninja]

Just got started on mine (been sick all week...ugh....) and so far just loosed all the Axle Torx Bolts...was quite easy. Know that mine is a CA/AZ Car (first year in GA though) so it's not that messy underneath, plus I have a AA Gen III Ex and custom springs, so my clearences may differ.

First, trip to Autozone. Picked up there:

1- 24" 3/8" Extension $9.99

1- Female Torx Socket E12 $3.99 Pt# 085903 2027 26830

I added my own 4" extension, and a large Torque Wrench for power. The night before I hit each one with some "PB Blaster". (smelly, but way better the Liquid Wrench IMO)

I moved the axle so I saw bolts at 11 & 2, placed the extended (28" total) socket on it (through one of my Red Vogtland spring coils) and used a Rubber Mallet to make sure it had solid contact, then pushed on the Torque wrench, pushed hard and "SNAP"...each one gave a crisp sound when breaking loose. Gave a few hand turns to make sure they were loose, then on to the next one. I was able to do two at a time this way no problem. Piece of cake! Thanks for the ideas! Next up the sway bar supports.....

[JETninja]

Look at post 69, you'll see that I did not remove the sway bar. I simply removed the two sway bar support and pulled it doen out of the way. I would recommend this only if someone is helping you remove the diff, and I would recommend that you get help. Wether you do what I did or remove the SB like Tommy R...its heavy and ackward taking it out.

Are these the two SB attachpoints that secure the middle of the Bar? If so, how did you do it, by removing the large bolts that go up into the chassis, or some how seperate the bar from the tabs? (I have TMS bars in place, they came with the car. Have only adjusted them, never removed/installed)

Thanks!

[ailey]

Hi Tommy,
Read your write up and with the pix the job was a breeze! Thank you, I had never worked on a Bimmer diff before I looked at your article!!
I pulled it out in 3 hours myself but now I have to redo the seals any helpwith that?
You Rock!
Brent

[banndit]

This is a great writeup. It helped a lot when I pulled my LSD from my parts car. Thanks again!

B

[Tommy R]

No sweat, guys. Happy to help. No idea on the seals as mine have been fine. If you're talking about the output seals to the axles, I wonder if you even have to drop the diff to do that?

Tommy

[ailey]

Thanks again Tommy,
But actually I need to do the driveshaft one... it is the worst, but while I have it out I could probably do the axles as well.
Any one know of link to do the seals?
Thank you
Brent

[ailey]

Hi All,

I finished my FIRST Bimmer rear diff including the seals (two sides and the main pinion seal!!!!)
If it wasn't for this forum it would have taken me 10 Hours but it took 3hrs (to remove the diff with lots of help from TommyR's write up) + 2Hrs to rebuild and clean and replace all seals 2 hours to reinstall and torque everything down!!! I am still greasey from the undercarriage but You can't wipe the smile off of my face . Time for a test drive

THANK YOU ALL!!!!!!!!
Brent

[M52 POWER!]

How long do you guys reckon it would take to switch the diffs of 2 cars at the same time? 5 hours with a helper?

[///M LIFE©]

This should be stickied.

[M52 POWER!]

Also does the car HAVE to be on jack stands at front and back? Or can I just have the rear jacked up? I ask because I only have 4 jackstands and have to swap the diffs of 2 cars, so they both have to be up in teh air at the same time. Can't put 1 down with parts all apart.

[clumpymold]

Also does the car HAVE to be on jack stands at front and back? Or can I just have the rear jacked up? I ask because I only have 4 jackstands and have to swap the diffs of 2 cars, so they both have to be up in teh air at the same time. Can't put 1 down with parts all apart.

Just buy 4 more jackstands. They're like $10/pair at Kragen.

[M52 POWER!]

If anybody knows what size socket is needed to remove the input flange please let me know!

The one shown here:

[Tommy R]

30mm.

Just make sure you get a thin wall socket or "turn" it like I did to the one in the picture. Otherwise it won't fit in there.

Good luck!
Tommy

[clumpymold]

i did it in 3 hours including jacking car up and setting it right... you don't need to take off sway bar .. just loosen 2 rear-most bolts and lower it down and let output shafts hang on it ... no zip ties needed.... its simple

i did 2.93 to 3.15 LSD on a E36 328is

Sweet. I'm about to attempt this tonight (and tomorrow).

What size "reverse torx" sockets do I need to remove those axle bolts?

[Jeffrie]

Also does the car HAVE to be on jack stands at front and back? Or can I just have the rear jacked up? I ask because I only have 4 jackstands and have to swap the diffs of 2 cars, so they both have to be up in teh air at the same time. Can't put 1 down with parts all apart.

Two Jack stands is all you need leave the front on the ground.
And yes if you like you can put one car down in peices, just block the wheels so it doesn't roll away on you or use the hand break.
I also didn't have to remove the sway bar just loosen it were the tabs are and got my helper to push it towards the floor out of the way while I loosing the rear bolts.
Took me 1 hour and 45 min to drop my old diff out and install my new one for the first time (with a good helper).

[hellrot325]

Two Jack stands is all you need leave the front on the ground.
And yes if you like you can put one car down in peices, just block the wheels so it doesn't roll away on you or use the hand break.
I also didn't have to remove the sway bar just loosen it were the tabs are and got my helper to push it towards the floor out of the way while I loosing the rear bolts.
Took me 1 hour and 45 min to drop my old diff out and install my new one.

Handbrake works on rear wheels...

[Jeffrie]

Handbrake works on rear wheels...

Mentioned while the car was down, you do not need to remove the rear wheels to swap a diff.

[hellrot325]

Mentioned while the car was down, you do not need to remove the rear wheels to swap a diff.

Misunderstood your post....my bad. Just didn'tr want someomne thinking that the e-brake would help w/ the back up on jacks

[clumpymold]

Okay, I just did this tonight (removed it, anyway). Not hard AT ALL. The hardest bolts for me, however, weren't the 6 E12 bolts on each axle flange. It was the four bolts connecting the differential to the driveshaft. 16mm.

I couldn't get a socket to fit so I had to use a 16mm wrench. I had to loosen two of them with my FOOT! Tough suckers. And I weighed the differential with my old bathroom scale. ~80lbs. FYI: I weighed myself right after. ~100lbs!

So yeah, if I can do this MYSELF, anyone can do it.

Now to get that bolt drilled/lasered out and the differential put back.

[5speed300]

Great thread!!! Im about to attempt to do this swap in the next week or two with a 3.23LSD that I just purchased, but first I have a few questions. I bought the differential without the output flanges becuase the seller informed me that the 99 M3 output flanges that came on the diff would not fit with my 325 axles. I know swapping hte output flanges is relatively simple, but I want to make sure Im not missing a gasket or anything that would come with the diff if the output flanges were still on the diff. Here are some pics of my differential, I would really appreciate if someone could identify anything thats missing from these pictures as it would help me tremendously.

Sorry for the pic size...



sorry for the blurryness...


So if you see any snap ring or gasket or anything I need before I stick my 325 output flanges in there I would really appreciate a heads up!! Thanks alot everyone!

[clumpymold]

Also does the car HAVE to be on jack stands at front and back? Or can I just have the rear jacked up? I ask because I only have 4 jackstands and have to swap the diffs of 2 cars, so they both have to be up in teh air at the same time. Can't put 1 down with parts all apart.

Not sure if this has been answered but I didn't use four jack stands. Jacked only the rear up.

Did this all by myself too. The hardest part, BY FAR, was getting the differential back in. I used my 3.5 ton jack and managed to position the diff vertical on the edge of the jack. Then slowly jacked it up while tilting the front of the diff down as it went up. Slid it in that way.

I removed the sway bar and found it VERY helpful. In fact, I don't think I would have been able to do this if it was still there. I have aftermarket sways (UUC) so they're pretty stiff/thick.

Anyway, good luck! Great thread.

Might I add some suggestions though?

It would have been nice to have a list of ALL the tools used for this DIY, as well as the torque specs for each bolt.

Oh, and it took me about 5-6 hours total for this job (over two days). I am a VERY slow worker (clean stuff, paint stuff, etc. ). I also took pictures and stuff. Sure was a major PITA and I really don't want to do it again.
The worst part of it is that I wasn't even swapping my diff. Only removed it to get my broken bolt out.

[Tommy R]

Did this all by myself too.

Did it alone the first time I did it, too. Much easier and faster with a second person. If for no other reason to hand you tools and, of course, to put the diff back in.

It would have been nice to have a list of ALL the tools used for this DIY, as well as the torque specs for each bolt.

Go for it!
Tommy

[clumpymold]

Did it alone the first time I did it, too. Much easier and faster with a second person. If for no other reason to hand you tools and, of course, to put the diff back in.

How did you manage to put the differential back in yourself? This is what I did (post #112 & on):

http://forums.bimmerforums.com/forum...=414611&page=2

[Tommy R]

I just lifted it and put it in the carrier.

Tommy