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S13/Z31 Trans swap for a SE

Started by Ju_S12_Turbo · Jun 15, 2012 · 11postsSMF 2010–26

Ju_S12_TurboJun 15, 2012, 3:58 am · #1

SUPER EXTRA ADDED INFO!

You can use a normal Z31 (84-89 non turbo 300zx)  transmission on a VG S12, Must be non turbo because the other trans are different! You still have to convert to a s13 front half because the z31 trans is as long as a s13/4 trans. It does fit and that is what I have in my car right now (Blew my other one up haha)

Everyone and their mom has done this for their S12, but not to many SE people have (that have posted at least) Thanks to "nismologist" and "David B" for the info I got from them (I will point it out). Here a link that helped me http://club-s12.org/v3/index.php?topic=25767.0

The Exact parts I used were, Side note, I say 240sx a lot because from my understanding the 180sx/200sx (any not ka24de) has a different front driveshaft.

1990 240sx Transmission (ka24e)
1993 240sx Front half of Drive-shaft (ka24de)
Stock SE Trans mount/Dog bone (slotted main mounting holes to fit )
SE Front flange on the 240sx Drive shaft.

Sadly I didn't take many pics but I have a few and a lot of pointers for problems I ran into.

First nismologist said that all his mounts lined up perfect, they didn't for me. I had to slot at least 2 of the holes for the stock tranny mount to work, it could be because I am running a billet aluminum mount but it fit perfect before so meh.

 What nismologist said about the SE/240sx(s13) drive-shaft is true (Major help ) and you have to impact your old flange off  (bigger bolt holes and farther apart) and put it on the front half of the 240sx(s13) drive-shaft.  This is the piece I am talking about
 posted image

Now you can take it to a drive-line shop if you have one local and if you uncomfortable with doing it the way David B (and me thanks david!) said by knocking off with a hammer. If you do it with a hammer, be sure you go from opposite side each hit and same with putting it back on. Be sure you crush the nut once it is tight .
posted image

Now, for the biggest problem I ran into which 90% of people will never run into, but at least people know.  If for whatever reason your input shaft cover breaks (thing that covers up the bearing and the throw out bearing glides on) a 240sx will bolt on, BUT it will put the clutch fork pivot point in the wrong spot. You can get a replacement online for 50$ shipped from www.nissanparts.cc (part number 32111V5001), if you need one asap you can get one from a Non-turbo Z31/300zx 84 and up (http://nissan4u.com/parts/info/32111V5001/). If you have a welder or a friend with a good welder you can do this! 
posted image
 posted image

Also you are going to need to cut the shifter spot back (Closer to you and better imo) by about 2.5 inches and you will need a 240sx shifter plate (S12 one only has 5 bolt holes that work, the normal big hole is not threaded on 240sx's) . There is also a extra sensor on the 240sx trans on the tail shaft housing, you don't need it but if it is missing your gonna have a bad time lol.

If you Decide to take the tail-shaft housing off (I would to check gear and stuff) make sure you put the shifter thing in (thing that goes onto the shift rod and what the shifter slides into, I forgot what its called lol) as you put the tail-shaft housing on or you will never get it on lol. I used my Stock Speed sensor and it mated up fine and reads the same speed (Gps verified ) as before.

 As for gaskets, I Honestly Use RTV (The stuff I used http://www.permatex.com/products/Automotive/automotive_gasketing/gasket_makers/Permatex_the_Right_Stuff_Grey_Gasket_Maker.htm) And just cleaned up all the mating spots with a razor and brake clean until nothing came off with a clean shop towel. Though I did reused my input cover gasket but I also put rtv on both sides and change the input seal at the same time. When you put everything back on make sure you put the bell-housing cover/spacer (thing that goes on the back of the motor) if you don't, your gonna have a bad time lol.

It honestly wasn't to bad, just take your time on stuff and try not to mess with the gear/shift forks with the case is off because if you do, well you might not be super stoked if the gears don't do what they are suppose to do lol.

I_heart_VVLJun 15, 2012, 1:49 pm · #2

Lots of good info in here. Good job dude!
+1 for sticky!

silvertonJun 15, 2012, 2:40 pm · #3

Benefits of the s13 transmission over the s12 transmission are?

I_heart_VVLJun 15, 2012, 2:58 pm · #4
silverton on 02:40:33 PM / 15-Jun-12Benefits of the s13 transmission over the s12 transmission are?
There's no real benefit, they both have the same ratios(except CA18DET tranny) and are equally strong. Availabilty/ease of access are the major benefits which helps when you blow out your tranny drifting and S13/14 parts are the only replacements. Not worth it IMO if your tranny is still good.

Now let's see a 30A swap guide! :D
seishukuJun 15, 2012, 9:09 pm · #5

The oiling setup on the S13 unit is a little better IMO.

200srdriftJun 15, 2012, 10:00 pm · #6

did you hammer the front half flange off so you wouldn't have to cut out the shifter hole on the trans tunnel??

JayJun 15, 2012, 10:18 pm · #7

No, he did it so that he had the proper length driveshaft. Otherwise it would be too long.

Ju_S12_TurboJun 16, 2012, 12:50 am · #8
200srdrift on 10:00:14 PM / 15-Jun-12did you hammer the front half flange off so you wouldn't have to cut out the shifter hole on the trans tunnel??
Jay on 10:18:39 PM / 15-Jun-12No, he did it so that he had the proper length driveshaft. Otherwise it would be too long.
  The reason I had to do this, was because the bolt holes on the 240sx Driveshaft were much smaller and they were closer together then the stock SE drive-shaft. When I change my clutch again I'll snap a pic of the two side by side
Ju_S12_TurboMar 16, 2013, 2:18 am · #9

Edited the first post, you can use a z31 (300zx non turbo 84-89) trans instead of swapping bell housings or anything of the likes, bolt up just fine. Still have to follow the guide for the drive shaft issues

WonderingravenMar 16, 2013, 3:21 am · #10

The mount holes for the clutch pivot fork was fab work because mine was also in the weird position as well taking from an z31 bell housing + ordered from nissan dealership for the cover plate.
When I do a clutch upgrade in the future I will snap some pics of my fabbed work on the clutch pivot fork.

My transmission was also Frankensteined from a 240sx paired from an blacktop sr20det 5 speed rebuilt with less then 100 miles on it with no drift tax.
z31 bell housing and s13 drive shaft paired with my s12 drive shaft. 

second_loveApr 7, 2013, 8:45 pm · #11

if a s12 has a vg30 it, you can use a 30a from a 87-89 turbo z31. i am coming from z31 world, the only difference will be the yoke on the front ds where it goes into the tranny.
84-late 86 turbo z31s have bw t5
all na z31s have 71c
87-89 turbo z31s have 30a
240sx has 71c
only differences are in tranny to bellhousing bolt pattern.

i will do a write up on this when i swap vg33et and 30a into my s12