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View Full Version : 4.10:1 LSD diff info


Slowered318
01-21-2004, 02:19 AM
Just incase anyone wanted to know.. this is what the inside of an E30 4.10 limited slip diff looks like..

Note the output shafts are very hard to turn in the oposite direction of each other, thus.. limited slip
*th-up*

Any other information people can add would be great, and use this thread as a refrence :idea:

Slowered318
01-21-2004, 02:20 AM
mmmmm... fresh paint :)

Slowered318
01-21-2004, 02:24 AM
results of my limited slip:

mkgino
01-21-2004, 02:28 AM
Is that from the E30 m3?

Slowered318
01-21-2004, 02:35 AM
Originally posted by mkgino
Is that from the E30 m3?

Nope.. 325ix from what I understand. bought it used.. it's more heavy duty then the origional 4.10 that came in 89-91 318is

Miguel
01-21-2004, 06:20 AM
4.10 + LSD = SEX

snd84318i
01-21-2004, 08:27 AM
would that fit on my 84 straight drop in ?

Eurostyle
01-21-2004, 09:19 AM
Originally posted by snd84318i
would that fit on my 84 straight drop in ?

Yes!*th-up*

Eurostyle
01-21-2004, 09:26 AM
I think i'm going to use a 318i 4.10 non LSD in my 325...just to see how it works out...

fabianyee
01-21-2004, 02:33 PM
My fren had a 3.73 LSD from an iX and it is much tighter - more lock percentage. I think it's 40%. As compared to his 4.10 LSD - 25%
It's a handful taking corners in the rain... Definitely not for the uninitiated...
However, it made drifting easier....

Slowered318
01-21-2004, 03:38 PM
Originally posted by fabianyee
My fren had a 3.73 LSD from an iX and it is much tighter - more lock percentage. I think it's 40%. As compared to his 4.10 LSD - 25%
It's a handful taking corners in the rain... Definitely not for the uninitiated...
However, it made drifting easier....

i hear ya brotha.. it's the drifters diff that's for shure, the thing is rock solid!

Mystikal
01-21-2004, 06:01 PM
Originally posted by Slowered318
Nope.. 325ix from what I understand. bought it used.. it's more heavy duty then the origional 4.10 that came in 89-91 318is

Actually, that is from the M3. The 325ix had the big box 3.91. M42's have the small box 4.10.

Mystikal
01-21-2004, 06:03 PM
Originally posted by Eurostyle
I think i'm going to use a 318i 4.10 non LSD in my 325...just to see how it works out...

LOL, you'll barely reach highway speed. :D

Eurostyle
01-21-2004, 06:40 PM
Originally posted by Mystikal
LOL, you'll barely reach highway speed. :D

No, not at all! When i went fron 2.73 to 3.91 on my old car my top speed whent from 185 to 195+*th-up* (remenber its an E)

Mystikal
01-21-2004, 09:19 PM
Originally posted by Eurostyle
No, not at all! When i went fron 2.73 to 3.91 on my old car my top speed whent from 185 to 195+*th-up* (remenber its an E)

Okay, I crunched some numbers. Your new max in-gear speeds:

1st: 21mph
2nd: 37mph
3rd: 57mph
4th: 81mph
5th: 100mph

You would need to shift to 4th to do a 0-60 run. :D It would slow you down more than anything.

BTW, if the 3.91 was on an otherwise stock ETA it could only hit 169km/h before the rev limiter. :huh?:

snd84318i
01-22-2004, 12:40 AM
i wish my speedo worked aaaaahhhhhhhhhh. im not saying i am going fast just feels like it . i was on 3rd gear and about 2000 rpms passing a speed checker ,it marked 37 mph i was shocked it didnt feel like it . but really how many of you hit that top speed on the highway . it feels good to have that power but unless you track it or 1/4 mile it every now and then you doesnt matter if you hit that top speed . but i would like to find a lsd diff . are there any spacific models to look for . or just look uder for that s on the diff ? thanks

snd84318i
01-22-2004, 12:44 AM
also how much power can the diff take . i know my m10 is weak but if i were to power it up how much ca nthese diffs take ? which diff should i look for ? how can you tell the #'s on the diff ( 410-391) are these #'s printed on the door or on the diff itself? thanks

fabianyee
01-22-2004, 01:18 AM
the iX LSD is viscous type LSD where as the M3 LSD is the clutch type...

As for the different in ratio, BMW had different ratio for different country...

snd84318i
01-22-2004, 01:55 AM
so for the USA i would have to look for the 410 . would the 4door rear from any e30 fit or should i look into 2door ones ? i ask because i go the junkyards in PA and last time i was there i saw 4 bmws 2 2drs and 2 4drs .when it gets alittle warmer here i would go back for more parts .

Mystikal
01-22-2004, 02:06 AM
Originally posted by snd84318i
so for the USA i would have to look for the 410 . would the 4door rear from any e30 fit or should i look into 2door ones ? i ask because i go the junkyards in PA and last time i was there i saw 4 bmws 2 2drs and 2 4drs .when it gets alittle warmer here i would go back for more parts .

Your car doesn't need any more than the small box 4.10. You can find that on '91 318's. The big box version was on M3's. They are all interchangeable.

Slowered318
01-22-2004, 03:01 AM
Originally posted by Mystikal
Your car doesn't need any more than the small box 4.10. You can find that on '91 318's. The big box version was on M3's. They are all interchangeable.

from what i see.. the houseing on the diff for 325's is bigger then 318.. but they all use the same back cover and they are all interchangeable. And why wouldn't a 325ix have a 4.10? maybe it was an automatic "ix"

It looks like a clutch type to me.. so i don't think it's out of an M3

Mystikal
01-22-2004, 03:14 AM
Originally posted by Slowered318
from what i see.. the houseing on the diff for 325's is bigger then 318.. but they all use the same back cover and they are all interchangeable. And why wouldn't a 325ix have a 4.10? maybe it was an automatic "ix"

It looks like a clutch type to me.. so i don't think it's out of an M3

Yeah they are different sizes between the 318's and all other models. Never thought about the automatics, that just fuxored all of my posts. *shiner*

Slowered318
01-22-2004, 03:19 AM
Originally posted by Mystikal
Yeah they are different sizes between the 318's and all other models. Never thought about the automatics, that just fuxored all of my posts. *shiner*

AHAHAHHAHHAHHA!!!!

mistikal ---> *mumble*

I tried to figure it all out before i bought the new diff.. but there is no real way to know what it is, till you tear it apart!

Mystikal
01-22-2004, 03:26 AM
Well, you DO know it's LSD by the "s" stamping on the cover. ;)

Jon@Bimmersport
01-22-2004, 03:39 AM
3.73 hard in the rain? lol..not really...i can floor it in 1st comming out of corner and it wont drift..!?!? why lol

Eurostyle
01-22-2004, 03:44 AM
Originally posted by Mystikal
Okay, I crunched some numbers. Your new max in-gear speeds:

1st: 21mph
2nd: 37mph
3rd: 57mph
4th: 81mph
5th: 100mph

You would need to shift to 4th to do a 0-60 run. :D It would slow you down more than anything.

BTW, if the 3.91 was on an otherwise stock ETA it could only hit 169km/h before the rev limiter. :huh?:


It was on a stock ETA, in the beggining anyways....and it didnt loose much top speed on the hightway...I remember hitting 180 on the way to Quebec city one day. The top speed run (195+)was with a few mods including a chip, exhaust, intake, FPR...

fabianyee
01-22-2004, 04:11 AM
Originally posted by Slowered318
AHAHAHHAHHAHHA!!!!

mistikal ---> *mumble*

I tried to figure it all out before i bought the new diff.. but there is no real way to know what it is, till you tear it apart!

Tear them apart??? Why do you need to do that???


Try this forum for info....
http://forums.bmwclub.com.my/showthread.php?s=&threadid=2852&highlight=Viscous

fabianyee
01-22-2004, 04:14 AM
Originally posted by E46_lover
3.73 hard in the rain? lol..not really...i can floor it in 1st comming out of corner and it wont drift..!?!? why lol

What lock percentage is urs???
The one i was tokking about is with 40% percentage...
My fren had a 25% lock 4.10 LSD and it wasn't a handful in the wet.. But the 3.73 40% lock LSD is.....

Slowered318
01-23-2004, 09:24 PM
Finally got it done!

It's gonna look good sittin under the car :)

snd84318i
01-24-2004, 12:00 AM
was the lsd diff not in cars dted back in 84 ?mystikal you say a 91 318 is that when they started to come out ?

Jon@Bimmersport
01-24-2004, 12:02 AM
i had 3.73LSD i dunno wat lock..came off a 325iS

Skunk#1
01-24-2004, 02:34 AM
generally the automatics in the vehicle i work on come with lower gears than the manuals. my .02.

Mystikal
01-24-2004, 03:50 AM
Originally posted by snd84318i
was the lsd diff not in cars dted back in 84 ?mystikal you say a 91 318 is that when they started to come out ?

The M10's had either 3.64's or 3.91's.

Eurostyle
01-24-2004, 05:04 AM
Originally posted by Skunk#1
generally the automatics in the vehicle i work on come with lower gears than the manuals. my .02.


No, most automatics in BMW's have higher rear end ratios....

Slowered318
01-24-2004, 08:17 AM
Originally posted by Eurostyle
No, most automatics in BMW's have higher rear end ratios....

trade off is.. they usually are not LSD, but it was an option.. so you could get lucky and find a 4.27 or higher with LSD.

YOU CAN buy gear sets for e30's if you have a nice LSD already, see Korman (http://www.kormanfastbmw.com ) but you have to set the spacers perfect.. or it will whine like crazy or shred the teeth off the gears.

snd84318i
01-24-2004, 03:47 PM
so my US 318i has a 3.64 or a 3.91 diff? and lsd was out back in those tdays too ? so if i find a lsd , would it best that it came off a 318 auto or standard , or the 325 auto or standard ? OR are they the same size in either case ?

Eurostyle
01-24-2004, 05:43 PM
Originally posted by snd84318i
so my US 318i has a 3.64 or a 3.91 diff? and lsd was out back in those tdays too ? so if i find a lsd , would it best that it came off a 318 auto or standard , or the 325 auto or standard ? OR are they the same size in either case ?

LSD was out back then, i had it on my 85 325e. Stick or auto wont make a differance in the early years, but starting in 89-91 the 325i auto had a higher ratio then the rest...

beamerboycsl
01-24-2004, 10:30 PM
i have a 25% lock stock on my 97 328i but when ever i spin the wheels only one side spins and i never catch pauze. what dif. do i have and how come i havent seen it lock.

snd84318i
01-25-2004, 01:51 AM
ok im confused then i my 318i is a 410 diff then how high do the #'s go . or is my diff not a for ten is there away i can check it to see .

BladeRunner
01-26-2004, 09:06 PM
Originally posted by fabianyee
My fren had a 3.73 LSD from an iX and it is much tighter - more lock percentage. I think it's 40%. As compared to his 4.10 LSD - 25%
It's a handful taking corners in the rain... Definitely not for the uninitiated...
However, it made drifting easier....

I don't understand...


Originally posted by snd84318i
i wish my speedo worked aaaaahhhhhhhhhh. im not saying i am going fast just feels like it . i was on 3rd gear and about 2000 rpms passing a speed checker ,it marked 37 mph i was shocked it didnt feel like it .

Yeah my speedo doesn't completely work either. It use to work off and on in the cold and hot, but once i hit a bump it would shut off again. I read somewhere it could be bad contact, which e30s seem to be somewhat known for or that white plug on the rear of the of the diff picture that Slowered attached ^above^.

I think BMWs are notorious for giving the impression that your not going fast when they really are. I know on the highway I frequently hit 70-75mph if I don't glace at speedo.


Originally posted by fabianyee
the iX LSD is viscous type LSD

Is it really, so that would make it better than M3 LSD, correct?

I think I read somewhere someone with either a M50 swap or turbo M20 setup was using this. Well now I know what to drop in if ever get the nerve to turbo my M10 or drop in and turbo a M20.


Originally posted by snd84318i
ok im confused then i my 318i is a 410 diff then how high do the #'s go . or is my diff not a for ten is there away i can check it to see .

I believe the numbers go up to 5 or 6 for aftermarket civilian use and even higher if talking rally...

I know in my car 1st gear->15-20mph, 2nd gear->30-35, 3rd gear->40-60 (i think never redlined it) 4th gear (never redlined) 5th gear (never redlined). I really should learn the metric system...

Empowered, a mod here at max posted awhile back to lift your car and look for a ratio imprinting or engraving on the final diff. If unable to find then turn the shaft and count the number of turns the shaft takes before the wheels make a complete rotation.

MatyBMW
02-04-2004, 04:33 PM
Hey Slowered318..

My diff is kindof winey right now. Know where I should go for a used 4.10OSD or 4.10LSD? What would be a good price for either. The cheapest I ever found for an LSD was $750.

Eurostyle
02-04-2004, 05:12 PM
I have a 4:10 non lsd for sale...$250

objec
02-04-2004, 05:42 PM
check ebay, for used ones, i bought one a month ago for 55 dollars, just alittle dirty thats all. it was 65 to ship it though, haha.

snd84318i
02-04-2004, 10:46 PM
i read somewhere that i can also have a 2.73 is there anyway to tell which one i have other than turning the drive shaft and counting te turns . im going to the junk yards and some might not have there diffs on them . so i would need to know about the diffs and what to look for if i come across that problem .

Slowered318
02-06-2004, 04:52 PM
Originally posted by MatyBMW
Hey Slowered318..

My diff is kindof winey right now. Know where I should go for a used 4.10OSD or 4.10LSD? What would be a good price for either. The cheapest I ever found for an LSD was $750.

Maty! what's up dood?

i got mine at shantaram but it was expensive (beat him down to 650 and ran with it) if you look for rebuilt ones it's a better way to go, but i haven't found one of thoes for under $1400 because the bearings alone are worth about $80 a piece, and when you add it all together with labor.. it's insane! I got lucky.. but i wouldn't trust a used diff off e-bay the spider gears and other parts could be broken and you wouldn't know till you hit the gass at the right time and BOOM!

If you diff is a 325, 3.73 LSD? then the best way to go is a 4.10 gear set from www.kormanfastbmw.com

MatyBMW
02-06-2004, 10:13 PM
Thanks man.. i'm going to go with the 4.10 non LSD and cheap out :) haha

felixthecat
02-08-2004, 12:59 AM
nice number crunching

Jase
02-10-2004, 04:01 AM
So if I have a diff from a 90 auto is is likley to be a higher ratio?. Isn't there anything on the case to identify the ratio?.I am curious to what the ratio of mine is.Any easy way to pick out the look of a LSD?.

qimis
02-10-2004, 04:12 AM
does the 1989 325is comes w/ LSD ?

Mystikal
02-10-2004, 03:57 PM
Originally posted by Jase
So if I have a diff from a 90 auto is is likley to be a higher ratio?. Isn't there anything on the case to identify the ratio?.I am curious to what the ratio of mine is.Any easy way to pick out the look of a LSD?.

All M20B25 autos are 4.10. The way to identify an LSD is an "S" stamped on the diff cover.

Mystikal
02-10-2004, 03:58 PM
Originally posted by qimis
does the 1989 325is comes w/ LSD ?

Yup

qimis
02-10-2004, 04:49 PM
which LSD does it comes with ?

Mystikal
02-10-2004, 04:49 PM
Originally posted by qimis
which LSD does it comes with ?

Manual: 3.73
Auto: 4.10

qimis
02-10-2004, 05:01 PM
*th-up* thanks a lot man

JCKL_racing
10-10-2004, 09:44 PM
Reviving old thread - great resource , glad that it got started!
I see that the 325i's with auto have the 4.10 - what about 86/87 325ES auto?
would this be 4.10, would it be lsd?
Thanks in advance.

MCK
10-10-2004, 10:28 PM
This thread was heaps helpful.
thanks everyone for your questions.
so will i be able to get both wheels to spin in the dry?
and also when cornering will it drift easier?
Will I notice a diffrence with my current Open diff to the LSD???

I'm off to replace my whinning 4.10 OSD for a rebuilt 4.10 LSD. unless i get told some negative things about the LSD...

Slowered318
10-11-2004, 08:48 AM
^^^^ I can't think of ANYTHING negative to say about the LSD diff, it is much more predictable then an open diff.. much better control *th-up*

paul christians
10-11-2004, 11:37 PM
what year is that????????mine has a 373 LSD in it!!!!!!!!!!!

everlast
10-12-2004, 03:55 PM
I see that the 325i's with auto have the 4.10 - what about 86/87 325ES auto?
would this be 4.10, would it be lsd?

What about an 88' eta? I just put one in my 325e from an 88' 325e that is limited slip.. i scraped the rust off JUST enough to see the S, and confirmed it after by spinning it, but I can't read the damn numbers.. it looks like 2.93 or something, is that right?

TurboBimmer
10-14-2004, 11:07 AM
I'm just jumping in this thread. I read all the posts so I'll give my general comments on what I know.

I was recently shopping for a LSD for my turbocharged 91 318ic. Like everybody, I wanted the famous E30 M3 diff which is the same as an auto 325 LSD (4.10:1 big case) . Since they are hard to find or overpriced, I got tired of waiting and bought a 1988 325ix automatic rear diff.

- The ix diff are 3.90:1 for the manual and 4.10:1 for the auto.
- They are LSD, they don't use a clutch pack but a viscous coupling.(no wear)
- The clutch pack diffs have a big S stamped on the carrier case and on the metal tag attached to a bolt.
- The viscous unit have no S on the case and have a V (for viscous) stamped on the metal tag.
- The clutch pack diff have a 25% lockup from factory, and can be upgraded with additionnal clutches from aftermarket to 50 or 75%
- The viscous coupling diff has an infinite variable locking ratio. It will lock from 1%?? to near 100% if there is a need for it, (if the wheel speed difference is enough to heat the silicone in the center section). I read that information from a BMW TIS printout.

My 318 had a open diff, 4.27:1 and small case. I didn't try it yet because my clutch is slipping big time and I'll install a clutchnet 4 puck soon, so I can't say if I like it or not.

everlast
10-14-2004, 11:23 AM
If you installed a line lock for the front wheels or had another way to stop the car from moving, you could jack up the one corner of the car before an auto-x, heat the coupling up as much as you can by running it in gear slowly until it wanted to push the car off the jack, locking up the diff to near 100%, then do DA DRIFT BAYBE in the auto-x and impress all the kiddies with cameras!

*th-up* :cool:

MCK
10-14-2004, 06:50 PM
I'm just jumping in this thread. I read all the posts so I'll give my general comments on what I know.

I was recently shopping for a LSD for my turbocharged 91 318ic. Like everybody, I wanted the famous E30 M3 diff which is the same as an auto 325 LSD (4.10:1 big case) . Since they are hard to find or overpriced, I got tired of waiting and bought a 1988 325ix automatic rear diff.

- The ix diff are 3.90:1 for the manual and 4.10:1 for the auto.
- They are LSD, they don't use a clutch pack but a viscous coupling.(no wear)
- The clutch pack diffs have a big S stamped on the carrier case and on the metal tag attached to a bolt.
- The viscous unit have no S on the case and have a V (for viscous) stamped on the metal tag.
- The clutch pack diff have a 25% lockup from factory, and can be upgraded with additionnal clutches from aftermarket to 50 or 75%
- The viscous coupling diff has an infinite variable locking ratio. It will lock from 1%?? to near 100% if there is a need for it, (if the wheel speed difference is enough to heat the silicone in the center section). I read that information from a BMW TIS printout.

My 318 had a open diff, 4.27:1 and small case. I didn't try it yet because my clutch is slipping big time and I'll install a clutchnet 4 puck soon, so I can't say if I like it or not.

Have you got any pics of your car?

JCKL_racing
10-15-2004, 12:26 AM
Cool info!!
Again, I am wondering if anyone can confirm that the 325ES (12/86 build date) has the same rear (410lsd) as the 325IS when built with the auto trans.
Also, the cable that attaches to the diff - what is it for?
Thanks.

Slowered318
10-15-2004, 12:46 AM
Cool info!!
Again, I am wondering if anyone can confirm that the 325ES (12/86 build date) has the same rear (410lsd) as the 325IS when built with the auto trans.
Also, the cable that attaches to the diff - what is it for?
Thanks.

i have no idea but the "cable" wire is for the speedo

JCKL_racing
10-15-2004, 01:03 AM
i have no idea but the "cable" wire is for the speedo
Thanks, that's great.
I'm wondering where Mystikal Jay is - earlier in this thread he seemed to be the "guru"?!?!?!

TurboBimmer
10-15-2004, 07:49 AM
Have you got any pics of your car?

Yep!
Here is my toy: (1st photo with M3 springs =1.25"drop; second photo with Racing Dynamic springs = 2.25" drop )
2nd photo was at Bavarian Auto Show'n shine 2004 edition.
http://www.geocities.com/bmw_318ic

http://members.roadfly.com/TurboBimmer/rollbar2.jpg
http://members.roadfly.com/TurboBimmer/BavAuto.jpg

Mystikal
10-15-2004, 12:43 PM
Thanks, that's great.
I'm wondering where Mystikal Jay is - earlier in this thread he seemed to be the "guru"?!?!?!

Heh, sorry. The 325es had a 2.93 LSD, regardless of transmission.

JCKL_racing
10-16-2004, 01:49 AM
Thank you Mystikal and Slowered for your answers, that was what I needed to know.

I am in the market now for a diff - definately something with more pop than the 2.93, but not as big as the 4.10 - in an LSD.

Halloween is almost here - anyone want to part with a pumpkin??!!