This conversion is easier if you are able to source all of the necessary SA63 parts, this is what I used:
- SX80/SA63 bell housing
- RT142 W58, 2S clutch & flywheel
- MA70 extension housing and shifter fork
- SA63 auto prop shaft
Bell housing & gearbox
I have read it is possibly to modify a 3Y bell housing to mate a W5* with a 2S/3SGE engine, I was able to find a 4SFE-W55 bell housing which didn’t need to be modified. It bolts up the same as the 4 speed, but two of the bolts from the 4 speed are too short for the new bell housing. The Toyota part numbers for the bolts are 90119-12168 and 90119-12028. The speedo cable will fit, but it will be inaccurate because the final drive on automatics is 4.1 instead of 3.9.
The clutch on my 2S was in good shape so I was able to re-use the clutch and release bearing. As for the fork, the RT142 fork I had wasn’t a good fit, so I reused the BW 4 speed clutch fork and the old clutch slave from my ST141 The SA63 auto crossmember can be reused and will line up
I couldn’t get a hold of a manual SA63 prop shaft so I had to use the auto shaft. I also have an RA65 auto prop shaft but it is the same length. the auto shaft is slightly too short, 610mm long in total). This still works, but not all of the yoke is in the gearbox. This car is just a daily, so this shaft will do until i can get a longer one.
Due to different engine sizes and wheelbases, the W series is fitted with different shifter positions depending on the application. A RT142/RA65 W55 is fitted further back when compared to an SA63, so the shifter is in a more forward position. This means that the shifter is in the wrong location in an SA63. To compensate for the ~+75mm difference, a 40mm section of the transmission tunnel would need to be cut so the shifter can fit.The better option is to replace the shifter housing and selector yoke with one that is further back. SA63 shifters are getting hard to find, so I will be using an MA70 supra shifter setup.
A clutch pedal box and clutch slave from a manual RA60/SA63/RA65 is needed. also the brake pedal needs to be changed as the auto pedal is too wide.