Wow.. What a great read.. Many thanks to the OP for such a detailed
how to on the diffs..
What gear oil do you use and how often do you change it out..
awesome write up
i have been trawling the web to find this info for sometime now and constantly drawn a blank
thanks
there is 1 minor detail i would like to clear up though, this only really applies to the euro cars
the euro 3.0 M3 came with the medium case LSD, same as the smaller 6 cylinder engines and it will fit inside the non M differential carrier and you can use the 320i etc propshaft if you swap the input flanges
the euro M3 EVO 3.2 came with the large case LSD
if anyone is considering fitting the M3 EVO LSD to anything other than a M3 EVO, the EVO differential carrier is needed
thanks again for the write up
Last edited by disco1986; 08-06-2011 at 02:37 PM.
easy sailor
Hi this is a great write up! If I wanted to replace the clutches inside my differential, is it necessary to replace all the parts you replaced? Just trying to get a range of costs for mine. I believe the clutches are gone for good... it struggles to inch the car forward when one output shaft isn't connected (broken... snapped clean on acceleration... have no clue why). So that prompted me to want to rebuild my differential in the future. I found this thread and I'm bookmarking now and I'll be re-reading it again to understand some more.
-Abel
- E36 328is ~210-220whp: Lots of Mods.
- 2000 Z3: Many Mods.
- 2003 VW Jetta TDI Manual 47-50mpg
- 1999 S52 Estoril M Coupe
- 2014 328d Wagon, self-tuned, 270hp/430ft-lbs
- 2019 M2 Competition, self-tuned, 504whp
- 2016 Mini Cooper S
You will want to replace all of the bearings and races when you dig that deep...they do not last forever...Do it right the first time so that you don't have to do it again.
As far as the output shaft, are you saying that the actual axle that plugs into the differential snapped or the half shaft that runs from the axle to the wheel?
This is such a great topic. Lately I have been reading into diffs as I (finally) got an original LSD for my 328i. Amazing details, pics, write-up. Appreciated.
It's amazing to see how much goes into it. I never was aware of how critical things are even even that you had to set these in the first place, like all the preloads and stuff.
I knew about the pinion preload, but never realized there is also a preload on the actual turning of the pinion (or is that the same as the bearing preload?).
I don't understand the carrier preload though. Is this the turning resistance of just the carrier when it sits in the casing, without the pinion installed?
It also seems that preload and backlash are interactive with each other, like in they effect each other. Then is must be a pain if you think you have the correct backlash, but then mess it up again because of wrong preload and vice versa.
So how is carrier preload set? There is no crush sleeve or anything or even a bolt to fasten. Or has it to do with the endcaps behind the output flanges?
1998 BMW M3 3.2 Cabrio • Alpinweiß III on Schwarz • German spec • 1 of 12
SMG • SRA • PDC • AUC • OBC • GSM • HK • UURS • IHKA • FGR • MFL
IG: https://www.instagram.com/iflok/
The half shaft that runs from the axle to the wheel. Also known as the CV axle or output shaft Seen on RealOEM. The 328 came with 38mm diameter ones too. I'll get pictures of it soon. I was like this when I saw it. I'm not 500 hp ++... It happened during a brief acceleration moment with wheelspin, I didn't dump the clutch though. I'm glad it didn't happen 2 weeks ago at the track (MSR Houston).
So I just finished swapping the axle and did both rear wheel bearings while I was at it (PITA..) If it wasn't for me doing the whole job inside my dad's machine shop (with AC) I would have gone crazy. Luckily I was able to make presses and pullers on command.
2. Another question is if you can add just one extra clutch and plate to the differential to have 3? I can adjust and machine anything for size no problems... but I'm just wondering if it has to be added in pairs?
Thanks for you time.
PS. Do you have measurements for how much force (besides the loose "25%") the clutches are supposed to hold from one side to the other? Like I said, with the output shaft broken on one wheel, I could barely get the car to move forwards, so I called a tow truck.
Last edited by 328 Power 04; 08-14-2011 at 10:42 PM.
-Abel
- E36 328is ~210-220whp: Lots of Mods.
- 2000 Z3: Many Mods.
- 2003 VW Jetta TDI Manual 47-50mpg
- 1999 S52 Estoril M Coupe
- 2014 328d Wagon, self-tuned, 270hp/430ft-lbs
- 2019 M2 Competition, self-tuned, 504whp
- 2016 Mini Cooper S
great info OP, thanks for sharing and explaining it perfectly.
ESS 625RAGE AGAINST THE MACHINE
It is the same as the bearing preload. It's the total rolling resistance of the pinion gear with both bearings, the crush sleeve, input yoke, and pinion nut installed.
Yes, it is the turning resistance of just the carrier as it sits in the casing without the pinion. The ring gear must also be installed on the carrier to measure this.
They really do not play into each other as much as you may think. Left to right shimming on the housing end caps determines the backlash. Once you figure out what thickness shims work to get the correct preload on the carrier, you add or subtract from each side to keep the combined thickness the same and shift the carrier either right or left to get more or less backlash.
You do not have to add in pairs, but if you do add an odd number, the two will go on the side of the spider gears opposite of the ring gear. The endplate is what will need to be machined down, and this will be the combined thickness of the clutch and dog-eared plate.
The exact range of numbers is in the TIS link that I provided. It should be in Newton meters and listed as "break away torque."
Thank you.
You're awesome! Thanks for your replies.
Do you know of any reason as to why my output shaft broke right through the shaft part? It doesn't seem to be a common thing, I've searched.
-Abel
- E36 328is ~210-220whp: Lots of Mods.
- 2000 Z3: Many Mods.
- 2003 VW Jetta TDI Manual 47-50mpg
- 1999 S52 Estoril M Coupe
- 2014 328d Wagon, self-tuned, 270hp/430ft-lbs
- 2019 M2 Competition, self-tuned, 504whp
- 2016 Mini Cooper S
Incredible information in this thread, thank you for putting it together. Can you tell me where you did your part number research? I'm going to be putting together a small case diff and would like to look up the parts for that.
If I ever need to do this, this is the perfect thread. . . . . . . and your relatively close to me as well.
Yes I am...I can give tips, hints, info, or hands-on if need be.
great write up - many thanks to the topic starter!!!
a noob question though - how does one test the diff? or what are the symptoms of a failed/becoming close to failed diff?
hi.
where can i buy
33141203801
BEVEL MATE SHAFT ?
I had a question regarding setting pinion depth, pattern and backlash.
Some places indicate that you should set backlash prior to checking the pattern for pinion depth. For example, http://www.differentials.com/technic...n-instructions
"Check the pattern for proper pinion depth only after setting the backlash. Brush three or four of the ring gear teeth with a moderate coat of gear marking compound in two different places on the ring gear. Rotate the ring gear past the pinion gear three or four times and then back so the pattern can be seen."
Believe it was indicated in this post that you set the pinion depth, check the pattern and then check backlash.
It seems there is no clear cut answer, but was wondering if anyone could shed light on doing this.
Looking to attempt a 3.46 swap from an e30 to an e36 and was trying to figure out proper order.
Thanks much for the great thread.
Really it can be done in either order. It was more of personal preference on my part. Changing the depth of the pinion really has zero effect on the backlash and I'd much rather know that my depth/tooth pattern is correct to avoid disassembling the pinion again from the differential. Backlash is controlled by the lateral shimming of the carrier and ring gear assembly, and that can easily be removed and adjusted as needed.
EDIT: To add to this also, you will likely find that the BMW gear sets have very good tolerances and will likely require no adjustment on the pinion depth to get a nice clean, acceptable wear pattern.
Last edited by orangehatter; 11-22-2011 at 07:42 AM. Reason: Added something
Thanks much for the response. It's easy to get overwhelmed with all the different opinions on how it should be done. I guess what really matters at end of day is the pattern and the preloads on the pinion and carrier.
I picked up a medium case 3.46 LSD. The condition of everything seems great so far. A friend and fellow forum member Flink loaned me his extra e36 M3 3.23 Diff to swap into. I'm in the middle of taking them apart and while waiting on parts, was trying to learn how to check/set backlash and preload. First hurdle was figuring out why the LSD and gear wouldn't fit into the other case and found that the trigger wheels were different - the donor LSD had a larger wheel than the e36 case could accept. I swapped them and it fit fine.
I am basically copying what you did, following your thread and when done, I will do a writeup as it may further help others. I am not having to swap the ring gear to a donor LSD as I'm putting everything into the e36 case, so won't need to get into spacers for the ring bolts.
So far, bought most of my stuff from rmeuropean - one thing I found in buying the bearings ( at least for the pinion) the SKG ones come with the races. From what I gathered with the Timkens, the races needed to be ordered separate. Not a big deal, but I think that's what accounts for the cost difference?
Found these links to be helpul - the first is an instructor from an Automotive Tech class showing how to do setup:
[ame]http://www.youtube.com/watch?v=dAqAqODmcj4&feature=related[/ame]
This one has a simplified pattern correction explanation that I liked. Reading that wheel on the TIS gave me a headache
http://www.drivetrain.com/parts_cata...tructions.html
A couple other questions:
1) When swapping the pinion for a first try pinion depth check, would the better shim candidate be the one that came with the 3.46 case and pinion I am swapping? I need to check the thickness and compare, but I would think that would make more sense than using the one that came from the 3.23 case. The pattern after doing a test fit with the original shim under the rear bearing race looks heavy on top of coast and drive side - meaning I need to move the pinion closer to the ring, and the pattern closer to the root, right? I am guessing that the other shim that came with the 3.46 is thicker, but will need to measure.
2) Did you end up having to use the Mercury shims? If so, where did you order them from?
3) For the axle caps and carrier shims containing the carrier bearing races, should those stay with their respective original cases or go with swapped LSD, Ring and Pinion unit? Maybe it doesn't matter if you are changing the carrier bearings and races anyways, but one set of mine looks much better than the other.
4) is the marking on the pinion set at the factory in relation to the Ring gear or the case the pinion originally went into? For example, on mine it is marked +5.
Thanks again for doing this writeup.
Last edited by jonb94118; 11-22-2011 at 10:22 AM.
regarding Lock up modification (for the center section) - I have done many, many........ of these.
IF adding 1 more to any e30 or e36 differential for a TOTAL of 3 clutch discs + 3 dog plates, NO MACHINING IS REQUIRED.
there is a 4mm spacer at the bottom of the case. Remove this steel spacer, replace with 1 dog plate and 1 clutch. if you order 2.0mm for these it will be = identical stack.
IF you want 4 clutch discs in the stock e30 or e36 188mm LSD, then the top cap would have to be machined. Some BMW OEM LSD units in 188mm have a thin top cap and 4 clutch disc conversion can be accomplished with 0 machining or modification. This is going deeper in parts bin compatibility than most DIY-er's will have parts for.
Some rare bird 188mm LSD's came from BMW with OEM 4 clutch discs. also Asymetrical center ramps (40/25% locking on accel/deccel)
Last edited by wanganstyle; 11-22-2011 at 11:43 AM.
Wanganstyle Powertrain
http://www.wanganstyle.com/
S54B32 E36 M3 DTA S100 Sedan Street car full swap:
http://forums.bimmerforums.com/forum....php?t=1437471
Bookmarks