I have heard that the JDM OEM LSD will only work in the JDM M2B4 tranny. Can any of you confirm this or dispell it as a rumor? I would think they would be interchangeable, but I have known to be wrong. I was recently told of this rumor, and don't know if its true..

 

I have a M2B4 and the LSD would fit in an M2F4. The ring gear is different, but the LSD was shaped about like a quaife and the whole assembly will fit. However, I have also seen pictures of "JDM LSDs" that looked much different than mine. They were a large cylinder which would clearly not fit. So I think it depends. My M2B4 LSD looked like the one pirate posted a picture of in this thread:

https://honda-tech.com/zerothread?id=1380516

 

the m2f4 i bought off madnessracing has a m2b4 lsd in it, or at least thats what they say....

it does have bearing problems though, im not sure if its because of fitment or normal wear....

 

I *think* these may be the ones that don't fit:

 

For reference, the other kind:

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">For reference, the other kind:
</TD></TR></TABLE>

Is that a viscous unit? Reason being, I might get this, but it says its viscous and I really don't want a viscous diff!!! I want one thats equalivialant to the ITR unit, torson type. http://cgi.ebay.com/ebaymotors...ZWDVW

 

I do not think that the JDM M2B4 style LSD will fit in a common USDM H-series casing. Flyrod's first post of different LSDs came from a Japanese site that has this pic of the engine-side tranny housing from a Accord SiR F20B:


This is My buddy's M2B4:


This is my old USDM M2S4 (Prelude Si nonVTEC):


The top 2 are similar but the last has different webbing/oil baffling around where the Diff would sit. There is a 45* bevel on some of the fins/webbing and the far right oil guide is slightly different too. I think that with slight modification the JDM OEM LSD could be used but otherwise as Satan_SRV said a long time ago, No the JDM LSD will NOT fit in the USDM castings without modification. I am not sure about the bearings or the width of the JDM LSD. I imagine it is similar and shims could be used to adjust the slop...

BTW the M2B4 diff is NOT viscous. It is a helical torque biasing LSD (like Flyrod's Pic).

Hope that helps, but probably not.
Pirate

 

ok now im a lil confused. an m2b4 is an lsd tranny, that i know. correct me if im wrong but y would u have to put an lsd in it? wouldnt the question be can an oem lsd fit in the jdm non lsd tranny(i forgot the code), or also can it fit in the usdm tranny? if the m2b4 is an lsd tranny y would that even be a question since it already comes with lsd?
just my .02

 

The M2B4 is the JDM LSD tranmission. People wreck M2B4s and other OEM LSD transmissions and later, upon disassembly, sell the LSD. People with USDM H-series tranmissions want a LSD but do not want to spend $1000+ for a Quaife or cannot use one since it is not OEM and may mess with their racing classes.

So, I was pointing out the difference between the tranmission casings that might affect the installation of the JDM LSD into a USDM H-series non-LSD tranmission...

Pirate

 

i could not get a usdm h23 case to fit the m2b4 bottom case . the taper on the lsd was to high. with a bit of grinding it would have but it came about 2mm to short . what a waste of a day that was

 

All very interesting..

So, there are 3 different types of JDM LSDs? The "cylinder", the "itr look-a-like", and the "funky ring" unit.

The "funky ring" unit, such in the ebay auction, is, in fact, a helical - torsen LSD, correct???? If yes, thats good.

The "funky ring" unit, can fit a m2f4 tranny? Yes, or no, or yes with modifications?

Just trying to get a consecious on this, I havn't had the opportunity to take a LSD H22 tranny apart..

 

I guess it will be hard to draw any conclusions without more people to post and corroborate some of this info. Re the F20 pics with two diffs: one looks like a clutch type and the other looks like a torsen type. Pirate's M2B4 pic is a torsen type. I've never seen a pic of the fluid coupling kind. I can tell you for sure that this one fit in my M2F4:



IMHO it works better than the OEM one in my M2B4, particularly in the hairpins.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">For reference, the other kind:
</TD></TR></TABLE>

I am now 90% sure that is a VISCOUS Diff. Same "design" as the nissan stock Viscous, and there are no holes anywhere, which means there is likely liquid inside..

 

ill have pics up in about 4 hours of all the gears and the diff from my m2f4 case w/m2b4 lsd and custom gears....

 

Looking forward to that..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Honda318dx &raquo;</TD></TR><TR><TD CLASS="quote">there are no holes anywhere, which means there is likely liquid inside..</TD></TR></TABLE>

There are a bunch of holes on the other side. I didn't take it completely apart however, so I suppose it could have a viscous element. Also, the Quaife LSDs only have a few small holes.

 

posted question in allmotor as well

 

I disagree about it being a viscous unit but I have never dismantled that particular diff. It has a lot of drag in neutral just trying to rotate the wheels with the front of the car jacked up, more than my Quaife did. I am pretty sure that the wheels would turn pretty freely if it were a viscous unit. Corey, where did you find the info on it being viscous?

Also here's some more info on tranmission housings, It was pointed out to me that there is a difference between the USDM M2S4 and M2F4 casings. The following 2 pics are of old M2F4tranmissions that I had apart or that friends had apart a while ago. Keeping large amounts of documentation are sure nice.




If you compare the previous pics of M2B4 and M2F4 casings, it looks like the M2F4 is the same as the M2B4 casings. So I ammend what I said before and state that you probably can use the JDM LSD in the M2F4 casing at the very least. I have no Idea about the 5th gen castings or the other non-LSD JDM ones though. It almost seems like we have made a little progress... Get those pics up mgags7.

Pirate

 

Awesome info Pirate..

Ok, now I'm doubting myself, everyone please read this..

http://auto.howstuffworks.com/differential1.htm

They "cylinder" units are probably viscous

The ITR copy has got to be a torsen..

But what is the "funky ring" diff????? This stuff is killing me.. Once we figure it all out, we will have a great FAQ.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">I disagree about it being a viscous unit but I have never dismantled that particular diff. </TD></TR></TABLE>



Thats definately a viscous unit. The shape is all wrong to be a torsen/quaife type unit, since you need a set of worm gears in the casing.

Also, with no holes in it, it must be self lubricated - that cant be done with a torsen.



The diff on the right is absolutely a torsen - you can see the worm gear sticking out of the case. The diff on the left appears to be clutch pack, you can see what looks like a friction disc through the holes on the top.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Thats definately a viscous unit. The shape is all wrong to be a torsen/quaife type unit, since you need a set of worm gears in the casing.

Also, with no holes in it, it must be self lubricated - that cant be done with a torsen.</TD></TR></TABLE>

I still vote torsen. It is shaped the same as a quaife, and as I mentioned it has a bunch of holes on the other side. A viscous unit would also have to seal around the axles too, wouldn't it? There were no seals or anything suggesting fluid containment. The axle sockets looked like the quaife sockets I've seen.

So I guess the question at the moment is, Has anyone taken one of these apart? Want does your diff look like mgags7? Want to pioneer a bit? That noise you were hearing could be from inside the diff ya know... Also, what does the Nissan viscous diff look like inside and out? Anyway, it's good to see something interesting around here, anyone else have some info? Could you elaborate machine4321? (I didn't quite follow your explanation)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">

I still vote torsen. It is shaped the same as a quaife, and as I mentioned it has a bunch of holes on the other side. </TD></TR></TABLE>

Are you sure you're looking at the right picture? Its definately not shaped like a quaife at all, the clearance just isnt there for the worm/spider gear arrangement found in a torsen type diff. This thing is flatter and has a rounded housing.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote"> A viscous unit would also have to seal around the axles too, wouldn't it? There were no seals or anything suggesting fluid containment. </TD></TR></TABLE>

Dont need to - it will seal internally.

 

Corey, I'd recommend Quaife over the OEM LSD for a few reasons.

The biggest one: It has a lifetime warranty, even when raced.

2nd: If one front wheel lifts and comes back down, the lsd will be damaged, then you're SOL with the OEM unit.

3rd: The quaife is maintenance free.

Furthermore, the Quaife is more agressive than the OEM LSD and would be better suited for the track.

Either way, both LSD's are good, but Quaife is clearly better, IMO anyway...



Modified by Paul H22A4 at 7:48 PM 10/6/2005

 

And here is some more confusing information about the OEM LSD from a PO.com post:
--------------------------------------------------------------------------------

As far as I know, JDM Prelude trannies are gear based or helical LSD. I confirmed this when installing mine (tranny code M2B4). ITRs have clutch based trannies and viscous is fluid based and can not be worn out).

Clutch based LSD can wear out and need to be replaced after awhile (like a clutch) but helical LSDs don't. Although they can be damaged under certain extreme driving conditions.

I got this from our friend at JDMHondaParts.com

There are mainly 2 types of Honda made LSD's:
Gear Type or Clutch Type
A third type is Viscous, but it's very rare and expensive.
Gear Types have gears inside of them that mesh/engage together when load is detected. This type is good to have because you'll probably never have to replace worn internal LSD parts, unlike the clutch type. The downside is that they can internally break if your into rough circut racing. Lifting a front wheel in a turn and landing back on it is how the LSD can break. Real stiff suspension is a major factor in making a car lift during a turn.

Clutch Types have small clutches inside that engage when load is being detected. These LSD's won't break if you happen to lift a wheel. The only real downside to this type of LSD is, wearing of the clutches. Just like the clutch disc inside of your tranny, the clutches inside this LSD wear out too, and needs replacement.

Viscous Type are similar to the viscous LSD's used in some AWD vehicles. The way these work is that a special fluid is used in the differential THICKENS, when excessive slip is induced. Stators and impellors in the diff make this even more efficient. Although there is a slight delay in locking of the differential, they work very well and last a long time.
According to my resources, these were 'special order' LSD's for JDM 96-97 ITR integra's only. No other countries would receive this optional LSD, only Japan. The cost was about twice as much as a the common Gear type found in all ITR's and CTR's. One odd thing though, Honda of Japan does NOT have this optional LSD type for 98+ ITR's! We're (EB & I) pretty sure it fits in 98+ ITR tranny's though...


Source: http://ff-squad.com/LSDcheck!.htm

Clutch based LSD:
http://auto.howstuffworks.com/differential6.htm

Viscous based LSD:
http://auto.howstuffworks.com/differential7.htm
__________________

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote"> Its definately not shaped like a quaife at all, the clearance just isnt there for the worm/spider gear arrangement found in a torsen type diff.</TD></TR></TABLE>

Ok, then turn the quaife so it's facing the same way... The quaife looks smaller than the M2B4 diff that has a different ring gear, and I hope we can agree that the quaife is a torsen type diff.






Modified by flyrod at 6:22 PM 10/6/2005