Modern
06-15-2007, 03:26 PM
Ok. So I have this project that I have been working on for 2 years (money has been tight.) It’s an rb26 in a s13. Now my problem is the transmission. I don’t have one. I know that a rb25det will work and I know a rb20det will work. Everyone on the forums say get the 25 tranny but I'm not going to be making 500whp anytime soon, so I thought about just getting the rb20 transmission and if it blows up I will replace the internals with a OS 5 gear kit.... http://www.splparts.com/Parts/Z32/Drivetrain/Tranny/default.asp....
and everyone on various forums says
"KA, SR, CA, VG30E, RB20, all use the EXACT SAME TRANSMISSION. Only the bell housing is different, and in some cases there's a different 5th gear. Direct swap with just a few bolts. "
ok that sounds good right. but I have been searching for days and found this.
http://www.zilvia.net/f/showthread.php?t=63529&highlight=bellhousing+swap+rb20...
"You will need a lot of patience and time to do all of this correctly. However, to make a long story short, the KA internals are longer than the RB20 and in addition the tail end is as well. Although you can use a KA tranny internals for SR, you CANNOT use them to replace a RB20 tranny without modifying your driveshaft and using the Mckinney mounts as I did on my RB, the shifter will now be too far back using KA internals.
We first tried using RB bell housing, KA internals and KA tail end, then attempted using RB bell housing and tail shaft with just KA internals. All of these were too long and I ended up acquiring another RB20 transmission. Needless to say we wasted a whole night assembling at installing the hybrid transmission. The reason I used a RB20 transmission originally on my RB25 was because it was readily available at the moment and that I was able to use the s14 driveshaft without modification.
"
so I’m looking for some clarification. I have my driveshaft cut for a rb25 in a s13. so if I do the rb20 will I need a new driveshaft (I know the yolk will need to change). and if the rb20 breaks can I swap internals (from a ka/ca/sr) and have it be the same size?
Thanks all.
and everyone on various forums says
"KA, SR, CA, VG30E, RB20, all use the EXACT SAME TRANSMISSION. Only the bell housing is different, and in some cases there's a different 5th gear. Direct swap with just a few bolts. "
ok that sounds good right. but I have been searching for days and found this.
http://www.zilvia.net/f/showthread.php?t=63529&highlight=bellhousing+swap+rb20...
"You will need a lot of patience and time to do all of this correctly. However, to make a long story short, the KA internals are longer than the RB20 and in addition the tail end is as well. Although you can use a KA tranny internals for SR, you CANNOT use them to replace a RB20 tranny without modifying your driveshaft and using the Mckinney mounts as I did on my RB, the shifter will now be too far back using KA internals.
We first tried using RB bell housing, KA internals and KA tail end, then attempted using RB bell housing and tail shaft with just KA internals. All of these were too long and I ended up acquiring another RB20 transmission. Needless to say we wasted a whole night assembling at installing the hybrid transmission. The reason I used a RB20 transmission originally on my RB25 was because it was readily available at the moment and that I was able to use the s14 driveshaft without modification.
"
so I’m looking for some clarification. I have my driveshaft cut for a rb25 in a s13. so if I do the rb20 will I need a new driveshaft (I know the yolk will need to change). and if the rb20 breaks can I swap internals (from a ka/ca/sr) and have it be the same size?
Thanks all.