hey guys - im new to this site, but not to cars. I love my e39 because its a great car but since i got it, the one BIG downside is that theres no LSD, and very little aftermarket options. Ive noticed that most of you e39 enthusiuasts are not using LSD's so i figured id help make it easier for you (you dont know what youre missing!!)
I am a strong believer in the quality and function of a smooth clutch rear diff (similar to what the M5 has from the factory) but I wanted something a little more aggressive. The OS Giken LSD's are just that -- and in fact the only diff I use in my personal projects is Carbonetic. In my experience they are far superior to Quaife, far superior to kaaz or cusco, and in normal driving you dont notice it... until you push it. Very predictable, zero chatter (and its well below freezing here) with great manners. On Xmas eve my friendly delivery guy dropped it off, and i took some pics before the big day
This can be installed by any competent home-mechanic with tools. I have broken it down and took pics almost every step of the way, i may have missed a couple minor things but the big stuff is in there. The end result is so bada$$ you need to do it to understand, there is no way i can explain in a forum post. However i can help you to do it yourself. Now to the fun part - heres my new project, the rear end is the one that needs some love this time around (the dog is named turbo):
the items you need before starting this project are:
axle seals from BMW (you should be able to just copy this part number)
(2) Quarts of OS Giken 80W-250 (makes the diff butttery smooth)
penetrating lube is your friend on street cars:
not shown: TOOLS, RTV (i recommend hondabond, it works great and never leaks, but black silicone rtv works great too), rags, brains
STEP 1: Spray all bolts with the PB Penetrating lube to ensure they come off easily and no problems
Next, drain the gear oil from the diff, then unbolt the axles:
**ooops i forgot to take pics of this its an easy step tho -- Remove the (3) mounts with an 18mm wrench + 18mm socket/ratchet (use a vice grip + 18mm socket on the pass side due to the trunk bubble). the front mount is a 21mm, use a ratchet and wrench here. Then get the diff ready to come out - if you have a friend use him, but its safer with a floorjack or tranny jack.
here is the diff after its been removed. i gently popped the axle stubs out with a mallett and breaker bar
remove the axle seal -- in the process of removal, it will get destroyed which is why i listed up there you need to buy (2) new axle seals from BMW
^^destroyed axle seal after removal
get the rear diff cover off and get ready for swapping
now that the axle seal is gone, careully remove the super-beefy massive Circlip that holds the diff's carrier bearings in place.
**oops i forgot to take a pic here, bu this is also pretty easy -- Once this circlip is out you can slide the bearing races out, then the diff comes out the top ****CAUTION - KEEP THE BEARINGS AND RACES TOGETHER NEVER EVER PUT THE PASS SIDE BEARING OR RACE ON THE DRIVERS SIDE AND VICE VERSA**** MARK THEM IF YOU NEED TO!!
Next, using an impact gun - Remove ring gear and bolts from stock diff (bolts normal right-hand-thread). Prepare the ring gear and bolts ready to go on the os giken LSD
Using aluminum soft-jaws in your vice to safely hold the OS Giken LSD, attach the ring gear and bolts
I use small amounts of red loctite on the bolts to ensure they never come loose. Tighten them to spec (i forgot to record the tq spec)
Using a bearing puller, carefully remove the bearings from the stock diff, *** AGAIN MAKING SURE YOU KNOW WHICH BEARING CAME FROM WHICH SIDE AND WHICH RACE MATCHES UP TO THAT BEARING****
carefully pressing the matching bearing onto the diff.
Bearings swapped! getting ready to install the OS Giken LSD in her new home:
but the diff is a little too big for the housing. We need to do some very light grinding/clearancing to make room. i use a 4.5" angle grinder, but this stupid website will only let me post 30 pics per page so this pic is missing too.
after grinding, the diff will sit in place:
carefully popped the diff in, put the MATCHING RACE TO THE MATCHING BEARING, made sure everything was clean, and now its time to re-install the circlip
making sure the circlip is fully seated, now its time for the new axle seals. I used an old piece of metal to carefully tap it into place, going in circular motions and being careful not to damage or force the seal.
***no pic b/c its basic*** now, use some silicone RTV on the back diff cover and carefully boolt into place, making sure the RTV is fully covering the diff:cover surface and preventing any leaks. Let it dry for a cpl hours.
pop the axle stubs back in...
hit with a mallett to make sure the clip is fully seated. (axles popping out if you dont do this is stupid and a pain in the butt)
fill w/ 1.5 qt of OS Giken LSD fluid
RTV dry, fluid full, diff is ready to be re-installed in my e39
Last edited by frgeoff; 01-06-2011 at 02:00 AM.
that's really sweet! Whats the price? Does it bolt up to the Oem shafts?
price is about 1700 bolts up to stock axles, KILLER performance, no other diff like it
Last edited by frgeoff; 01-04-2010 at 04:22 AM. Reason: Automerged Doublepost
this is only available for 6-cylinder cars, right?
nope 8 cyl too. the 8 cyls dont require any grinding
I think you misunderstood my question.
I'm saying can you remove this (yes, remove ring gear, too):
from the M5 and bolt the 540 ring gear on and bolt it into the 540 case? basically how frgeoff bought JUST the LSD, swapped the ring gear and all, re-sealed, re-shimmed (I think), and reinstalled it in the SAME case.
Most auto manufacturers don't change much between RWD differentials typically 2 or 3 cases w/ varied options - LSD, cooling fins, mounting differences, etc.
However, I can't find a breakdown of individual part numbers [at realoem.com] for an M5 diff and/or a 540 diff. When I say individual, I mean diff bolts, bearings, seals, ring gear, pinion.
"real" LSDs are always expensive. My 240sx drift-specific diff (ATS Deftforce) was $1300+ when new. Their quiet, smooth-engaging Carbon LSD was closer to $1800 and there is a far bigger market for those.
Last edited by mattmartindrift; 01-05-2010 at 09:19 AM. Reason: Automerged Doublepost
Last edited by frgeoff; 01-04-2010 at 04:08 PM.
i think it was like 18$ each
very very cool stuff. I always enjoy looking at diff stuff.
I cant tell from the pics but is there a shim between the bearing race and circlip?
also what is the break away torque of these LSDs. I assume its greater than the usual BMW 25%
there is no shim used in this differential - the bearing is just held in place by the circlip
... and just to irritate the purists some more, thats a 2jz head on the floor
Last edited by frgeoff; 01-04-2010 at 06:52 PM. Reason: Automerged Doublepost
I cant say if you would appreciate it as much as me... if you know how to drive the car the improvement is dramatic and really lets the e39 explore its potential. LSD is really the only major chassis difference from the M5 to the non-m's.. and with an os giken in place your car is basically an underpowered m5 but with small brakes and a steering rack
Last edited by frgeoff; 01-04-2010 at 07:41 PM.