Hi, I’m new on the block. I need some info from a transmission expert. I have a 90 integra ls Y1 transmission. So I decided to install a LSD in to the transmission, so I bought a ’98 ITR JDM LSD, only the differential, with out the final and the countershaft, thinking that I only had to swap the final, well the final of the Y1 dose not fit the 98 LSD differential, it is to small to fit, so I went an bought a 98 ITR final and the countershaft. The description said that is was a 4.4 final. I bolted the final to the differential and try to install it, it didn’t fit, the housing of the Y1 had some nipples or small lips, so I went a head and remove them, there a re like 2 or 3, lips, the size of 1” after that the LSD fit perfect. I counted the tees of the final of the Y1 and the tees of the ITR and they were 66 tees, they look the same and the countershaft look the same too, so I did not change the countershaft of the Y1 for the ITR, it look fine to me. I gave it a rotation and there was no grinding or getting stuck, it felt fine to me. But to make sure that everything was correct, I brought the transmission to a shop to check that everything was right. The car runs fine, at 80mph it revs at 4300rpms.
But my question is, do I have to change the countershaft from the Y1 to the ITR one? What’s the deferent’s from the Y1 and the ITR countershaft, if so what is the deferent’s?
Will the response of the transmission be different? Or just leave it alone?