Installing 94+ GSR gearset and Factory LSD into a 92-93 YS1 cable clutch case

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As most of us cable transmission owners know it's getting harder and harder to find decent transmissions without bad synchro's. I had turbo'ed my b18a1 powered 90 Civic Hatch and was using the stock YS1 LS transmission. While this setup is supposed to be ok for turbo's, the transmission still sucked. That was mostly because it was worn out and didnt have an LSD. Unfortunately the North American Honda/Acura cars never came with an LSD (the exception being the Integra Type R)The type R gearing is a bit low for a turbo application so thattransmission still sucked. That was mostly because it was worn out and didnt have an LSD. Unfortunately the North American Honda/Acura cars never came with an LSD (the exception being the Integra Type R)The type R gearing is a bit low for a turbo application so thats where sourcing out a JDM transmission came in. Luckily for me, my friend Jon had a S80 LSD transmission with no synchro grinds. He was kind enough to sell it to me for a great price and this is how this whole writeup started.
Having a cable clutch car leaves only a few options.
1) Change out your cable clutch and install a hydraulic clutch system. This has been done by many people but I didnt want to bother with hacking up my car so I looked for other routes.
2) Buy the HASPORT EFB2 kit. This kit is designed to work with your existing cable clutch setup while allowing you to install the newer hydraulic clutch transmissions. I was going to go this route but the cost turned me off so I looked for another way to do it.
3)Install the new LSD and gearset into my old cable clutch case. To my knowledge this will only work in the 92-93 YS1 case as it shares pretty much the same case as the newer hydraulic transmissions. The only problem is that the LSD is bigger so you will have to do some grinding inside the case to make it work.
During my research on how to install the gears I couldn't find anything that would give me concrete info on what needed to be ground down. It was quite obvious once you took the two transmissions apart, but if you had no previous transmission experience(like myself), the thought of taking it apart and grinding parts can be a bit overwhelming. I was fortunate enough to find a guy on that has completed this job more then once. He was kind enough to send me his phone number so I could ask any questions I had during the changeover. His username on g2ic is .J.
I wanted to setup a How To page on doing this job since I couldnt find another one on the web. If you keep reading below I will try to walk you through all the steps(with pictures) of exactly what you need to do to make this work.
**DISCLAIMER: I am not responsible for any damages that you may do to yourself or your transmission while following my guide. It is intended to give you an idea of what needs to be done but is by no means the full complete step by step process**
You will need the helms manual for the 92-93 integra to do the changeover. It can be confusing when it comes time to put everything back together so the exploded view found in the manual is a big help.
You can click on any of the pictures to open the full sized one. Press the back button on your brower to return to this page.

Taking the tranmission apart
Taking the transmission apart isn't very hard. If you follow the instructions below and read the helms manual you shouldn't have any problems. I didnt take enough pictures when doing the dissassembly so I emailed the creator of a great writeup on what I am about to tell you. He was kind enough to let me use his photos. Check out his site as he has a lot of other great howto's for Honda's. You can find his howto's HERE.
The photo below shows some of the different bolts that will need to be removed before you can split the case of the transmission:

Arrows #1 and #2 point to the "detent" ball covers. The detent ball is used to help hold the shift fork in it' different positions. Remove the two set bolts. Underneath will be a spring and a ball bearing(5/16"). They are both the same size so you dont have to worry about which one goes where. The drain and fill plugs can be left in for now.

The photo below shows the other bolts that will need to be removed to split the case:
You will need to setup the transmission off the ground a little bit as the input shaft sticks past the end of the clutch housing.
Arrow #1 points to the cover that you will have to remove in order to get to the unhook the snap ring from the counter shaft. When you get it off the countershaft should drop a little bit which is a great indication that you suceeded. You will need a snap ring pliers to do this properly but some needle nose pliers can actually work if your imaginative.
Arrow #2 points to the bolt that aligns the reverse idler gear shaft where it should be and prevents it from rotating. Remove it.
Arrow #3 points to the oil fill plug.It may be a good idea to loosen it so that you dont have to fight with it when your transmission is back in the car and you are ready to add oil.
Arrow #4 points to a cover plate for the "oil gutter plate". There is no need to remove it.
Once you have these bolts removed, remove the transmission housing bolts in a criss cross pattern (a couple of them are indicated by arrow #5.) Once thats done you will also need to remove the reverse light switch.

Splitting the Case
Below is a picture of the snap ring you will need to pry apart in order for the countershaft to drop a little bit.

After that you can gently start prying the two cases apart. You may need to hold the snap ring open and pry gently if it didnt end up fully releasing the first time. There is no need for a lot of force or using a hammer.

Removing the internals
Once you have the case apart you will see something like this:

This is an image of the YS1 transmission. The parts that i have pointed to need to be removed. The picture above shows the reverse shift fork #1 and the reverse idler gear #2. Remove both of these. The next picture shows the shift piece/change holder #3. Remove it as well.

Once these three items have been removed you can safely remove the counter shaft #4, mainshaft #5 and the shift forks #6(Note: the other 2 are hidden from view), as shown two pictures above. Note the position of and be careful not to lose the spring washer and the other washer that are between the bottom mainshaft gear and the bearing in the case. I found the best way to remove the shafts and shift forks was to grab all of them at once and slowly lift up. Everything should come out nice and easy.
It should be noted that you should inspect the shift assembly for wear. I had some troubles with my YS1 transmission not going into 4th gear sometimes and the problem was that there was a groove worn into the shift piece.
After the gears are out the only thing left is the differential and final drive. It is fairly easy to remove. I grabbed ahold of the bearing and wiggled back and forth while lifting up on the differential.

Once it is out your transmission should look like below. Notice the ribs in the case that are sticking up? Those are what needs to be ground down. You will see exactly what needs to be ground down when you remove the differential from the donor transmission (if it has an LSD). I am not sure if there is any grinding to be done on the YS1 case when installing a non-LSD differential so if someone knows the answer they can email me here.

Below is a picture of the S80 transmission. Notice how the ribs are ground down? That is what you will be trying to duplicate when your finished.

didnt want to take everything apart to do the grinding so I used a plastic bag and some duct tape to seal off any areas that i didnt want to have aluminum filings exposed to. You should remove the speed sensor as well so that you can clean around where it used to sit. I used an angle grinder because its all i had. Its a pretty tight fit and works for some areas but i would probably use a dremel next time i did it.

Once you are done grinding it should look something like this:

I sort of eyeballed what needed to be removed based on what the other transmission was ground down and I ended up having to retry a few more times. Make sure that the LSD is not touching anything when you are done. Its hard to tell if its hitting unless you bolt the case together so thats what I recommend doing. Just set the differential in the case and then bolt and torque up the bolts and make sure the diff can be spun without much resistance.
Of course before you get to the step of putting the differential into the freshly ground case you will need to change the diff bearings. You will notice that the YS1 uses a semi-sealed type bearing and the donor transmission uses a cone style bearings with seperate race. **Note that i do not know if all 94+ hydraulic transmissions have the different style of bearing** Its really easy to tell the difference as they are completely different looking bearings. I ended up reusing my YS1 bearings(curse my student budget!). I didn't have access to a puller or press so I took the two diffs to a driveline shop and had them switched over. The YS1 diff bearings are pretty beefy so they were still in good shape after being pulled off the old diff and pressed on the new one. If you think you may have damaged the bearings during removal don't attempt to reuse them.
Now that you have the new diff installed in the YS1 case you will need to check a diff thrust clearance. To do this you need to bolt and torque down the other half of the case and use a bent feeler guage to inspect your clearance **Refer to manual for exact steps and for service limits**
You will also need to check the mainshaft thrust clearance**Refer to manual for exact steps and for service limits**
**Note that special tools are needed to check the end play of the mainshaft once you have found out the right thrust shim size. These tools are around 150 dollars U.S and can be found at your local Acura dealer.(refer to manual for part numbers.)
Now that you have the new diff installed in the old case you will want to put the gearset/shift forks back where they came from. I found the best way was to hold all of them together like they would go once installed and slowly lower them down into their proper spots. It can be done with one guy but would be even easier with an extra set of hands.
Below is a picture of the YS1 case with the S80 internals.

put a thin layer or silicone around the transmission to seal the two cases together and prevent oil leaks.

Then I bolted it together and torqued the bolts down. Installation is reverse of dissasembly.
I havent had a chance to drive the car since I installed the transmission again but I have shifted it through the gears while it was on jackstands in my driveway. Everything seems normal so far.
Here the link to the thread i got this from Installing 94+ GSR gearset and Factory LSD into a 92-93 YS1 cable clutch case


Brutal Moderator
Did you let them know that you're copying and pasting their entire article, pictures included, on to a different site?


LX-R coming soon
Did you let them know that you're copying and pasting their entire article, pictures included, on to a different site?
I sent him several email's but no response from him. This was originally was posted back in 05 he may have moved on but he did post this in a public forum for other to use so i help him out by pass it on but i am not going to take credit for his work. He put a lot of hard work in that wite up so lets use it.