rb/ka transmission a success.

[frosted flakes]

my rb tailend of my transmission cracked and all my fluid leaked out so i remember reading that the ka tailend will bolt up. so i swapped transmission internals and tailend. It was pretty easy swap took about 2-3hrs. now the shifter sits a bit back (in the s14 atleast) instead of forward. Im using stock motor mounts and transmission mounts. I also installed my new act clutch (heavy duty pressure plate with 6puck race disc).

The KA transmission i have is kind of old so it doesnt feel as good as my rb transmission did but it was defintley a good cheap replacement and something i had laying around. if something ****s up with your rb internals or casing then remember that u can bolt up the internals of the KA along with the KA's casing, but u must use the RB bellhousing in order to attach to the rb20. you can pick up KA trannies for cheap so its really not a big loss if u **** up your rb transmission.

[BoostFab]

nice to know this theory is confirmed. how did your rb20 casing crack ?

[StricNyne]

nice man, an rb transmission goes for roughly 1000 dollers haha, how go the gears feel though

[Carl H]

when you say it sits back what do you mean?like sits back from center or back from where it normaly is if you used the rb transmission.also you are using the gts-t xmember and mounts right?

[frosted flakes]

i mean the shifter sits back instead of forward. im using stock skyline motor mounts and xmember.

[accel junky]

Flippin sweet. So did you use the ka body and rb bellhousing? Because when you said took internals out, sounds like you used the RB body and Rb bellhousing, but KA internals.

Also, did you have to use the RB input shaft?

Thanks,Daniel

[frosted flakes]

no RB bellhousing, KA internals and KA "internal casing". the internals include the input shaft.

[accel junky]

Cool, any difficulties? Have you had previous experience working on trans? I may have to do this if my RB20 trans explodes.

[frosted flakes]

nope this is the first time i ever took apart a transmission. it was fairly easy.

[Wulfgang]

I thought Projectrb240sx already tried this and it did not work?!? Maybe not.

How are back from center does your shifter sit?

[BoostFab]

hey man post a picture of how your shifter sits. now everyone know that if your rb20 box breaks...there's a replacement option....thanks again for sharing

[accel junky]

I thought Projectrb240sx already tried this and it did not work?!? Maybe not.

How are back from center does your shifter sit?

He did do it and it worked, only he said to use the rb20 input shaft.

[Dano]

thats FAQ material right there... thanks for the info!

-Dan

[jj06]

whats up i know im late on this but i just found the post. would an automatic rb bellhousing be the same as the 5 speed? what clutch are you using rb or ka?

[frosted flakes]

sup. shifter sits a little rearward but its ok. i should have a pic on my cardomain.

umm no 5speed bellhousing is different that auto. you must use the 5speed RB bellhousing. and use the rb flywheel/clutch/pressure plate (300zx clutch and pressure plate works too)

[Jayzeon]

My Rb transmission took a crap also and was searching for a answer, only question I have is when you took it apart did you have the transmission sitting up or laying down. I have a 90 nissan 240sx hatch transmission sitting in the corner of my garage.

[Karma240]

I have a ka transmission on my rb20 as well. I live in tempe, az if anybody is thinking about doing it and wants to see it. I will tell you there are some difficulties. for instance. the casing is longer so unless you want uneccesary force put on the bearings then you need a custom cut drive shaft. the ka transmission also sits back quite a bit further in the s13 chassy so there is some cutting to be done to ensure the shifter will fit properly.. I did all of this and I am now going back to the rb20 transmission.. for the money you will spend to do this the "right" way you might just as well use the rb20 transmission...

Karma

[Shahee1]

How did you get your driveshaft to work ... did you get a custom from scratch or did you get your stock customized???

[Andrew85cm]

Damnit maybe I shouldnt have made my KA transmission into a lamp. Oh well. LOL At least I can still pull that shifter arm thing for when I get a B&M short shifter.~ANDREW~

[Karma240]

I got a new custom drive shaft made.. And I regret it everyday because Now that I am going back to the rb20 transmission I am going to have a new custom drive shaft made..

Karma

[OKCA18DET]

so, if i put the RB20 bellhousing, onto my KA transmission...into an S13 i'll need a custom drive shaft because it will be longer?

now my next question is which part of the transmission is longer? the bellhousing or the internals casing?

[Carl H]

from what i can understand the tailshaft and the tailshaft casing is longer on the ka, hence the need for a custom driveshaft.

[OKCA18DET]

so if that being said, could i just put the KA internals inside my RB transmission? my RB doesn't go into 3,4,5,Ri only get 1st and 2nd

[themadscientist]

cripes man, were you planning on getting around to fixing that? Can someone with a KA and RB transmission answer a question for me. Are the bellhousings the same length? Not the entire transmission, just the bellhousing part. Also, is the friction surface on the KA and RB flywheels the same diameter?

[OKCA18DET]

cripes man, were you planning on getting around to fixing that? Can someone with a KA and RB transmission answer a question for me. Are the bellhousings the same length? Not the entire transmission, just the bellhousing part. Also, is the friction surface on the KA and RB flywheels the same diameter?

i'd love to fix it, if a transmission shop can rebuild the transmission or fix the problem...but i dont know if they canit would be nice if someone on this forum knew if the internals were the 100% exact same as a different nissan then maybe the transmission shop i choose (aka my car dealership) will have a better chance to help me lol

[themadscientist]

I had a CA with no reverse for about three months, passenger was reverse. So are the bellhousings the same length?

[Carl H]

i believe that projectrb240sx rebuilt a rb20 transmission using sohc transmission parts, he posted up his findings a long time ago.

[Shahee1]

I recently had to do the transmission swap and the internals almost look identical. The RB tailshaft is much shorter but it look as if you can swap the parts amongst the two to create a totally new transmission. The flywheel and clutch are very different. I'm using an OS Giken Twin so I am not totally sure about the flywheel but when they are die by side my stock RB abd stock KA flywheel look different.

[FAST-DATSUN]

RB20/RB25DE trans he is talking about NOT the RB25DET trans which is larger/// and the shifter will be moved rearward which may cause problems for some.... RB20/RB25DE trans should go for 250/400 at most shops that import the motors..

[Wulfgang]

All of this stuff has already been answered if you search a bit more.

#1 the KA24 and RB20DET bellhousings are the same length, but obviously have different bolt patterns.

#2 the KA24 transmission is quite a bit longer than the RB20DET transmission

#3 according to projectrb240sx, the internals are mostly not interchangeable. Also according to him, the swap DOES NOT work.

#4 according to frosted flakes, the swap DOES work, but the shifter sits back from center.

#5 according to my tape measure, the shifter should sit so far back from center (2") after the swap that you wouldn't be able to shift, leading me to believe that frosted flakes' car had some previous frame work that allows him to use the KA rear case.