Well, Rathyna’s S13 not only had a roached engine, but her transmission had given up the ghost as well. It didn’t shift well, third gear was broken and her clutch was slipping. In our last article we had done a comprehensive rebuild of her car’s tired SR20DET engine and now it was time to go through her gearbox as well. Rathyna had a few transmissions in her junk pile, so we decided to take those all apart and see what we could salvage. Hopefully we could get enough good parts from them to make one good transmission.
We dug through the parts pile and found a counter shaft in good condition. After cleaning we sent it out to get shotpeened and then WPC treated. The shotpeening we prescribed was a severe one to improve the gear set’s fatigue strength. WPC treatment also improves fatigue strength, reduces friction as well and improves gear surface life. You can read more about transmission prep in this article and we basically followed those steps to improve the durability of the stock transmission.
None of our the parts in the pile had a decent third gear. We ended up getting a new one from Fontana Nissan as well as some seals, synchros and bulk rings.
We found a nice main shaft and shotpeened and WPC’ed it as well. The lustrous sheen on all the parts is from the WPC processing.
Once we got our parts back from WPC, we started to assemble the gear stack on the main shaft, pressing them into place.
We used balk rings from the parts pile that were in good shape and got a few new ones from Fontana Nissan.