View Full Version : LSD

Gord Galloway
05-28-2002, 08:41 PM
A friend of mine just finished putting a SOHC ZC motor into his 89 civic (street car) and complete drive train. He claims that it uses the same series of tranny however it has a factory LSD. My question is that if this tranny is of the same series does anyone know if I can just swap out diffs? Reason I ask is because I can pick up one of these Japanese spec tranny's for about $400 canadian.... ANY COMMENTS?????

05-28-2002, 09:04 PM
not all trannies were LSD. you gotta check and they are rare.

Jon Nelson
05-29-2002, 10:34 AM
I asked this question on the CRX forum, and was told NO. I was hoping there would be a cheaper option than the usual 700.00 us ones.

There was never a Japanese Market D series tranny sold with a limited slip diff of any sort. (They say....)

Tyson; you say that they are rare.... like hens teeth? or one year inparticular, or just from integra's, or ?? Maybe a new one from Honda IS available?


Jon Nelson

Chris Sawatsky
05-29-2002, 11:33 AM
there IS jdm zc trannies with factory lsd's in them. Rare, though.
I don't know whether or not the diff would work in an L3 tranny like we use, but I would imagine yes.

05-29-2002, 01:00 PM
The JDM ZC SOHC 1.6L 16v engine usually was installed in the low-buck Honda Integra in Japan (there is no Acura in Japan) usually with the automatic trans. It is almost identical to the CRX Si D16A6 108hp engine that was sold in the US and Canada. The CRX's in most other continents (Asia, Europe & Australia) had the JDM DOHC 1.6L 16v engine with 130hp and some of the CRX SiR models had the factory LSD which is rare indeed. I do not know if the factory LSD is swappable into the US/Can CRX models, but the gearbox itself will bolt up. Also note that some of them had the more desirable 4.40 FD too.

Since the ITC rulebook states that only vehicle models available in the US are elegible, then the whole gearbox would be illegal, but if the LSD fits in the US gearbox, then that would be a legal swap. Also note; SCCA does allow Canadian models.

05-30-2002, 04:01 AM
jon, which forum did you ask on? i know if you asked again on perf forum you would have gotten the right answer by a handful of ppl.

Jon Nelson
05-30-2002, 10:16 AM
I asked at the preformance forum.

I actually recieved a reply from Brain G!

I specifically asked if there was a JDM lsd and/or FD that would swap into the D series box.

So, if I am not mistaken, I should be able to call a (knowledgable) importer and get a ZC box with an LSD, a 4.4 FD, and still have enough parts left over to build a decent street tranny using the ZC gears?

Of couurse, there's probably some confusion. I would bet that some people are mistaking the fact that the B16A powered CRX (SiR) came with a LSD and a 4.4 FD, but that is all B series stuff, and won't swap into the lowly SOHC D series tranny.

Opinions anyone?


Gord Galloway
06-01-2002, 11:11 AM
There is a very good Japanese spec only parts importer here where I live and this friend of mine had no problem getting this Trans. and it was in the neighborhood of $400 canadian. Having said this I may try to order one and if the parts don't fit I will put it into my street CRX! Thanks everyone for their imput and if anyone else has anything to say I will still keep checking the post.

Gordon Galloway
Honda CRXsi
IT2 #32

06-03-2002, 10:16 AM
check out www.phantomgrip.com (http://www.phantomgrip.com) for a good LSD at a very reasonable amount

Gord Galloway
06-05-2002, 12:20 AM
Unfortunately we have already discussed the phantom grip and have determined that it burns out diffs and doesn't work that good due to the fact that the spider gears in a factory diff really weren't designed to have these loads on them...but thanks anyway!

06-05-2002, 01:11 PM
I've found Improved Touring! This would be my first post here...

I have a JDM "ZC" LSD tranny - yes, they are also of the "L3" series. I do not know specifically what Japanese cars came with the LSD equipped L3. Here's what I know:

-The LSD option is rare. I looked for 7 months to find a factory LSD equipped L3.

-The tranny case of the "ZC L3" is identical to the Si trim level cases with the LARGE diff. bearing. In other words, if you didn't already know, the L3 tranny's came with 2 different sized diff carrier bearings. The larger of the two measures 40x80x18. So, any and all of the ZC L3 tranny guts will swap into a US tranny case. I had to do this because of the condition the ZC tranny was in when I received it.

-The 1-5 gearing of the ZC L3 is closer than any L3 available in North America. The ratios are:

As for the FD options. All the FD ratio's I know of are:
2.954 = CRX HF
3.250 = CRX HF (California spec)
3.888 = Civic Hatchback, CRX all trim levels except Civic std., Civic Si, and CRX HF.
4.058 = All Civic 4 door Sedans
4.250 = Civic/CRX Si

[edit] any of these FD's can be used in any 5-speed L3 tranny. Obviously, you will need the countershaft and ring gear as a set.

There is no factory 4.4 FD that I know of that fits into an L3. I'm not going to say that there is no 4.4 for an L3, but in 4 years of fooling around with 88-91 cars, I've never come across that ratio.

Very Important:
You should be aware that the ZC L3 diff, LSD or not, uses the larger spline "Integra Sized" inner axle joints. The smaller Civic/CRX inner axle joints will not work in the ZC L3 diff.

I don't know jack about ITA/SCCA rules, but I do know that the DOHC ZC motors use a half shaft (intermediate shaft) that BOLTS ONTO a D16A6 block. The threads are already there for you. Do not assume that the int. shaft from the similar D16A1 in the 86-89 Integra will fit. The 86-89 Integra int. shaft is different than the ZC int. shaft.

That said, your axle options are as follows:

-Use stock unequal length axles, but replace the inner joints with 90-93 Integra inner joints.

-Use the ZC int. shaft and 90-93 equal length Integra axles. You will have to remove the dust ring from the inside of the steering knuckles so that the integra outer joints do not bind against those dust rings.

-Use the ZC int. shaft with 2 Right Hand (short) Civic/CRX axles fitted with 90-93 Integra inner joints. No steering knuckle dust ring removal required.

-DO NOT use 86-89 Integra axles. The spline diameter of the inner joint is correct for the ZC diff, but the length of the joint cup is too short. The axle shaft will come out of the cup on sharp turns.

[another edit]
For referance, my motor/L3 tranny/driveline is made up of the following:
-Endyn rebuilt JRSC D16A6
-90 CRX Si tranny case
-ZC 1-4 gears
-Si 5th gear
-Civic Sedan FD
-ZC int. shaft
-stock Civic RH axle with 90-93 inner joint
-90-93 integra LH axle, dust ring removed
-90-91 Civic sedan steering knuckles and brakes.

The list goes on, browse my site.
I've got more info on these trannys on my webpage:

Just look for "The L3 Transmission" link.

Hope I've helped, seems like I've written a book up there.

[This message has been edited by -TJ (edited June 05, 2002).]

[This message has been edited by -TJ (edited June 05, 2002).]

Richy Gonzalez
06-05-2002, 06:54 PM
WOW, thanks for the info. I do believe that the rules for IT class in SCCA would allow the iner guts of the tranny to be replace with that of another within same model (CRX SI). However, the swap would become illegal when you start using Integra parts to bolt everything together. Personally, if someone was lucky enought to put one of these combos together, it would be okay in my book http://Forums.ImprovedTouring.com/it/cool.gif

Richy Gonzalez
#21 ITA CRX (http://communities.msn.com/TheGonzalezFamilyRichySheilaandNyah)

B Breon
06-06-2002, 09:58 AM
The IT rules specifically say that only the stock gears can be used (the ZC gears may be stock, but not in the US) and the final drive and diff are the only open items. As for the drive shafts, it doesn't say, so I would say you can't do it.

Brent Breon
Cendiv ITA #26

B Breon
06-06-2002, 09:59 AM
The IT rules specifically say that only the stock gears can be used (the ZC gears may be stock, but not in the US) and the final drive and diff are the only open items. As for the drive shafts, it doesn't say, so I would say you can't do it.

Brent Breon
Cendiv ITA #26

06-06-2002, 10:15 AM

The gear swaps are not legal. Period. Those gears were not available in a US model, therefore are off limits. It doesn't matter how much effort someone puts in or how well executed it is, it's still illegal.

Final drives are open. If you can find a Japanese or whatever final drive to fit the d-series trans, have at it.

Don't even touch the driveshafts, as they are off limits.


[This message has been edited by il8apex (edited June 06, 2002).]

06-06-2002, 10:20 AM

I agree with Brent on this one, the use of that tranny is illegal and from the information given my view is that no matter what you do you are illegal.

Gord, I vaguely remember the argument about the phantom grip, but don't remember that conclusion. I put one in our new CRX we are building to test it out and we took it out for the first time on Wednesday and while the car had the usual first time bugs and was neither corner weighted nor aligned, it went like hell. We are basically breaking in the engine so we were soft pedaling it and trying to keep revs fairly even, but I encountered no problems with the LSD. It seems to me more then a few ITC hondas run them and I bought the product from a guy who runs a very competitive ITC honda down in Tennessee. Be interested in your comments. I may very well have to change that out this winter

We are testing the car at Gingerman, our home track, and hope to debut the car at the double regional in July. Hope you make that one Brent.

Dick Plank
Maybe ITA 63 if SCCA mails me my license so I can get that # in Cendif

Richy Gonzalez
06-06-2002, 12:30 PM
Did I say "legal", what I really meant was "illegal" http://Forums.ImprovedTouring.com/it/biggrin.gif

Richy Gonzalez
#21 ITA CRX (http://communities.msn.com/TheGonzalezFamilyRichySheilaandNyah)

06-06-2002, 11:38 PM
A late addition to this discussion but I have an '89 CRX Si ZC street car with a Phantom Grip LSD. At $250, I thought it was worth the risk and after about 10K street miles and three weekends as a lapping day instructor car the LSD function is pretty well faded away. I'd say there is some function and better still than an open diff but I'd say it has less than 30% function remaining. Certainly plenty of wheelspin in light driving in the wet or an autocross. If I wanted a tighter LSD for racing, I'd go back to the OPM unit I've used before if not stepping up the money to a Quaiffe. I told the IT based company that I bought the PG from that it would be used on the street and they said they didn't see any reason why not to. Within 6 months when it wasn't as tight anymore, they weren't particularly interested in hearing any questions that I had. As racers we try things. Some work, others don't.


06-07-2002, 07:55 AM

Thanks for the comments. There are a couple of different sets of springs one can use to "tune" the LSD in the PGRIP. Exactly how that works or how effective it is I have not the foggiest idea. But if I had to guess and that is all it is, I would say the springs went away over time. I put the much stronger race springs and for hard street applications I would put the upgraded springs. I suspect you had the standard springs in the unit. Anyone know who makes these things that we could talk to? It sure would be nice if we could depend on these given the price, but it way well be another you get what you pay for.

Dick Plank

06-07-2002, 08:34 AM
These springs are not custom built for this application. They are usually a standard machine spring used in tool & die manufacturing. Most quality machine shops have the springs in stock. Take your old springs to the shop to compare in their spring shop manual. There is a color code on the spring that determines the spring strength. You can look this info up in the manual and decide which strength of spring to try next.

Also, if you suspect the spring is weakened, they can compress and test the spring similiar to the way that race shops check suspension coil springs. Then they can just look up the spring weight info to see if it is within spec.

[This message has been edited by racer-025 (edited June 07, 2002).]

Gord Galloway
06-24-2002, 01:45 AM
I had the opportunity to drive a similarily prepared car this weekend except that it had a quaife...WOW what a difference!!!! You don't realize what differnce it makes untill you try one. I have thought all along that I don't get wheel spin in my car so why do I need one? Well the reason I don't get wheel spin is because I sub-consiously don't apply power in situations where the wheels will spin causing understeer...Driving the car with the quaife I could plant the powr down way earlier in corners with no chance of wheel spin and much faster exit speed...I AM SOLD! now I just have to sell my left nut to afford one!!!!

Jon Nelson
06-24-2002, 08:41 AM
That's interesting..... I've been grappling with the thought of getting a quaife for some time now, my same reasoning was "I don't get wheelspin", so maybe that shoots my theory out the window.

Was the car you drove similarly prepared to yours in terms of spring rates and swaybars?

I switched to a larger rear bar this spring, I can't beleive the difference it has made. It almost FORCES you to apply power earlier, where I had to be feathering the throttle before to avoid understeer at the exit, it now rotates completely through the corner. The night and day difference would likely be similar to what you experienced.

On second thought, why not get that testicle on E-Bay as soon as possible, get a quaife, and let us know how you like it.

Mind you, you'll be running with a little less "testicular fortitude" than before, it might adversly affect your laptimes.


PS - See you this weekend? See posts about where to stay in Gimli!

Gord Galloway
06-28-2002, 09:16 PM
True Jon, the car definitly has stiffer spring rates. however some of the places I was applying power would definitly without a question cause the inner wheel to spin and cause brutal understeer whereas the quaiffe just planted the power. I have been debating going to a stiffer spring but am undecided as what to run.

Gordon Galloway
Honda CRXsi
IT2 #32

Gord Galloway
08-02-2002, 09:11 PM
One of the Civic's were running had a Phantom grip LSD...I don't ever recommend anyone running these for a road course circuit and here's why. We were 46 laps into the roughly 60 lap race and suddenly bang! The car wouldn't shift and the tranny lost all it's oil. This tranny does have a few track KM with the Phantom Grip. Anyways we pulled out the tranny and tore it down. As soon as we got the case apart we could already see a couple pinion gears in the bottom of the case. One of which was jammed between the case and shift linkage. which is what broke the case. When we finnaly got the diff out it turns out the extra pressure put on the pinion gears and the pinion shaft caused extreme wear on the pinion shaft. The ends where the pinions ride was worn so bad that it was roughly 2/3 it original diameter and finnaly the shaft broke spewing the pinion gears into bad places. This was my original suspicion with the phantom grip as the factory diff just wasn't designed to withstand these extra forces from the phantom grip unit. Now my theory is confirmed. If you have a phantom grip and are happy with it I would still recommend pulling the tranny out once in a while, tear it down and inspect your pinion shaft and other related parts to ensure the same catastruaphic failure doesn't happen to you!

Gordon Galloway
Honda CRXsi
IT2 #32

Mista Bone
08-06-2002, 05:55 PM
Sorry, the your tranny failure was not the result of the Phantom Slip unit.

88-91 L3 trannys do NOT have a harden pinion shaft where as 92+ S20 trannys do.

As much as I hate the PG, it was not it's fault this time.


A PG will show damage from heat/scoring behind the shim that the side pinion gears on the differential casing.

How bad does the J.B. team hate me for my comments?

They ran me off the road on I-71 southbound, 1/2 way between Mid Ohio and Columbus.

I'm not gonna be a regular on this board, was just linked here. If you have any tranny questions.......

[email protected]

My Honda Tranny page......

it does need some updating though.

Just a D series tranny guru.

[This message has been edited by Mista Bone (edited August 06, 2002).]

Mista Bone
08-06-2002, 05:56 PM
delete this

[This message has been edited by Mista Bone (edited August 06, 2002).]

08-06-2002, 10:09 PM
Good to see you on this forum, M.B. I have been trying to keep up with your info via honda-tech.com but your feedback will be appreciated here...