# RS5F30A vs RS5F31A...



## Lazarus_023 (Jun 3, 2003)

Is there anything that'll keep me from changing to the 31A in my B11s? input shaft? bell housing? engine plate? output shafts? mounting points?

i've seen some info here, but no explicit "werks / dunna werk."


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## blownb310 (Jun 10, 2002)

Lazarus_023 said:


> *Is there anything that'll keep me from changing to the 31A in my B11s? input shaft? bell housing? engine plate? output shafts? mounting points?
> 
> i've seen some info here, but no explicit "werks / dunna werk." *


 Laz,
I haven't actually done this swap, but I did consider doing it at one time. When I checked into it, this is what I found. I can confirm that the B12's ['87 and '88 only] RS5F31A transaxle will bolt into a B11 [which of course originally had the slightly lighter duty RS5F30A trans]. There is one catch: the front trans mount bracket that bolts to the front of the case [near the fill plug] will not match up right. The location of the holes is different. This is not too big a deal to get around. You'll have to make an adapter plate or modify the bracket.

The input shafts are the same. If you are keeping the original B11 flywheel and clutch [180mm] you'll have to stick with the matching B11 throwout bearing. However, while swapping in the 31A trans, you might as well also swap in the 31A's flywheel too, which is [190mm]. This would require using the B12's 190mm clutch and matching T/O brg. In other words, don't mix the clutch parts. 

The only detail I cannot comment on, is whether the inner axle joints are the same. You'll just have to put a B11 and a B12 axle together and compare them. 

One other possible bonus: If you are using the RS5F31A trans, you should also be able to use a Phantom Grip LSD with it. I know they don't list the B12's on their application list, but they do have them for the B13 and B14's, which use a variation of the same RS5F31A trans. Might be a sweet combo.  

Hope this helps.


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## Lazarus_023 (Jun 3, 2003)

grooovy. now, didn't the '83-'84 turbo pulsars come with the RS5F31A? if'n so, the mount would be handy, and i'd at the very least have SOME half-shafts to use (even if they are muy espensive...).

i'll have to look into this, methinks.


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## blownb310 (Jun 10, 2002)

Lazarus_023 said:


> *grooovy. now, didn't the '83-'84 turbo pulsars come with the RS5F31A*


 I've heard that before, but I'm not really sure. Can anyone out there confirm that? Interestingly enough, if you look into an '83 Nissan Pulsar turbo service manual supplement book, they say that Turbo Pulsars were only equipped with automatics. There isn't even a manual trans section listed in the '83 Turbo Pulsar service Manual supplement. I know for sure that isn't true. I do know that they used a 200mm clutch instead of the 180mm that all of the other N12's got.


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## Lazarus_023 (Jun 3, 2003)

yeah, i'll confirm that next time i'm at my parent's place... i gots an NX turbo w/ 5-speed... what do i look for?


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## Crazy-Mart (Jul 14, 2002)

look out on the VIN plate to see if it the same part ##


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## MyClunkyAss12er (May 16, 2003)

the nx turbo didnt have the 31a but had the 30a with a 200mm clutch setup. many e15et owners do the swap to the 31a to handle the added power though.


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## Lazarus_023 (Jun 3, 2003)

MyClunkyAss12er said:


> *the nx turbo didnt have the 31a but had the 30a with a 200mm clutch setup. many e15et owners do the swap to the 31a to handle the added power though. *


poop. oh, well. i suppose the 30A will do me ok fer now...


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## blownb310 (Jun 10, 2002)

Lazarus_023 said:


> *poop. oh, well. i suppose the 30A will do me ok fer now... *


 Years ago I tried using junkyard 30A's, but they blew up pretty quicky, as they were tired when I bought them.

I have run 30A's for quite some time and the most important thing I have found, is to replace the bearings in a high mileage unit. They live very well then. 

Ever since I started rebuilding my own transaxles, I stopped breaking them. I have two spares on the shelf right now, one's got 3.89's [N12] and the other's got 3.65's [B11] in them. They're both ready to go, but I have not needed them.


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## BeEleven (Jan 22, 2003)

Hey blown...what do you think the chances are that my 125K mile tranny is gonna blow when I crank it up for the first time? I have no idea about its condition except that it wasn't raced. The only bit of advice I've heard thusfar is my dad's "Transmissions usually hold up alright"...haha..my g/f just had her Honda tranny rebuilt and she has about 150,000. BUT...in the event you think it will self destruct, perhaps I could trade you my old one plus cash for one of your rebuilt ones....?


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## Lazarus_023 (Jun 3, 2003)

blownb310 said:


> *Years ago I tried using junkyard 30A's, but they blew up pretty quicky, as they were tired when I bought them.
> 
> I have run 30A's for quite some time and the most important thing I have found, is to replace the bearings in a high mileage unit. They live very well then.
> 
> Ever since I started rebuilding my own transaxles, I stopped breaking them. I have two spares on the shelf right now, one's got 3.89's [N12] and the other's got 3.65's [B11] in them. They're both ready to go, but I have not needed them.  *



sell em? to me?

i've got two good boxes... one's a low miles 310 (4.52s, heh.) and the other a brand new 3.89 (i *think*). i've managed to take out the synchos on a RS4F30A (original tans w/ 120k miles..) and blew the diff out of a RS5F30A (100k... did a burn-out 'till the spiders welded.  ) i got enough raw parts for some groovy trans setups given the above gears... but i want more power and less breakage. (my driving habits will not change... i already got the crappy gearbox nearly blow'd out of my spec v). i figure the 30As will be good enough for my (planned) high-horse engine (with new bearings, of course), but i don't think they will hold up to my (also planned) drag (read "torque") engine... i migh have to go with a 31A...


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## MyClunkyAss12er (May 16, 2003)

do u all know what parts i can swap out on my 31a to get taller gears and in the end higher top speed(im tired of having to shift so early so i want it geared better for the e15et.)? id appriciate anything u could tell me.


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## Lazarus_023 (Jun 3, 2003)

MyClunkyAss12er said:


> *do u all know what parts i can swap out on my 31a to get taller gears and in the end higher top speed(im tired of having to shift so early so i want it geared better for the e15et.)? id appriciate anything u could tell me. *


heh. some higher gears. you'll have to do some mad looking around... try oem-surplus... they've got some 31A parts... tou'll have to see what you can come up with. try looking in service manuals or parts ists to see what year cars got what gears, and put together your ideal box. i happen to stumble magically over everthing i need, so i won't be too much help, but if i see anything, i'll let you know


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## MyClunkyAss12er (May 16, 2003)

cool. thanks alot. i still ahvent gotten that manual forthe pulsar! im relally gettin pissed.....


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## blownb310 (Jun 10, 2002)

BeEleven said:


> *Hey blown...what do you think the chances are that my 125K mile tranny is gonna blow when I crank it up for the first time? *


 Well it's hard to say! My experience has been that the input shaft ball bearing and the two mainshaft tapered roller bearings wear out on them. Any 30A tranny I have ever hurt, was from bearing failure. If you end up needing a gearbox, let me know.  

Now as far as Lazarus, dumping the clutch and doing burnouts, well.......no 30A will live long doing that.


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## BeEleven (Jan 22, 2003)

blownb310 said:


> * If you end up needing a gearbox, let me know.
> 
> *


Will do!


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## Lazarus_023 (Jun 3, 2003)

blownb310 said:


> *Now as far as Lazarus, dumping the clutch and doing burnouts, well.......no 30A will live long doing that.   *


heh. burnouts: yeah. don't burn one tire for 5 minutes with the parking brake on... the spiders don't like it... clutch side-stepping: just get a cheep clutch... it'll go before the trans!


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## Lazarus_023 (Jun 3, 2003)

now... even better. how about the RS5F32A (or V) from a 200SX?

anyone?


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## blownb310 (Jun 10, 2002)

Lazarus_023 said:


> *now... even better. how about the RS5F32A (or V) from a 200SX?
> 
> anyone? *


 I doubt anything on those would fit on an E16. Laz, empty your mailbox. It's full and I can't send you a pm.
Thanks!


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## Lazarus_023 (Jun 3, 2003)

MyClunkyAss12er said:


> *the nx turbo didnt have the 31a but had the 30a with a 200mm clutch setup. many e15et owners do the swap to the 31a to handle the added power though. *


heh. just got a chance to look at mine...

RS5F31A. like i thought. 

jackpot.


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## MyClunkyAss12er (May 16, 2003)

hmmmm, amybe the aussies got the weaker trans than us. i got my info from an aussie site.


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## Lazarus_023 (Jun 3, 2003)

and to top it all off, i checked #'s on drive shafts... they are the same. YAY!


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## Crazy-Mart (Jul 14, 2002)

Lazarus_023 said:


> *and to top it all off, i checked #'s on drive shafts... they are the same. YAY! *


thats a really nice info you got there !! ...


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## Gsolo (Sep 11, 2003)

bringing up an old topic here...ok then, I gotta 87 pulsar nx xe....do i have 30a or 31a? I'd look at the plate but its locked up in the shop...and i need to buy output shaft seals for it and there is a difference. anyone tell me for sure? i've heard that the 31a was for 87 and up sentras....


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## B11sleeper (Oct 15, 2003)

i think the 30A was 83 - 86 sentras, so an 87 would have 31A. might be wrong, but I think that was the cutoff.


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## Gsolo (Sep 11, 2003)

B11sleeper said:


> i think the 30A was 83 - 86 sentras, so an 87 would have 31A. might be wrong, but I think that was the cutoff.


thats what i was thinking...mitchell says 31A so i'll go by the book. But...for the seals it would be about a week if i order them  so i'll do without. The old seals will be sufficient for a bit. I have to get the car put back together and out of the shop before my teachers get upset about it...although they dont help much when they keep interupting me to tell me something i most likely already knew.


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## Red_Coupe (Mar 20, 2003)

Gsolo said:


> thats what i was thinking...mitchell says 31A so i'll go by the book. But...for the seals it would be about a week if i order them  so i'll do without. The old seals will be sufficient for a bit. I have to get the car put back together and out of the shop before my teachers get upset about it...although they dont help much when they keep interupting me to tell me something i most likely already knew.


when you order the seals just say it's out of a 87'e-16I 5 spd tranny ,and they should the right ones


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## Gsolo (Sep 11, 2003)

red_devil said:


> when you order the seals just say it's out of a 87'e-16I 5 spd tranny ,and they should the right ones


Thats what i thought...but shucks has it listed for the 30A...after showing them how to use the computer we found out the ones for 31A would take 4days, dont have 4 days. Went to Jerry's (local parts house) and they listed both, 30A on stock but 31A would take 5 days. If i dont have 4 days i dont have 5 days. So i'll just stick with the old ones i guess...not much i can do. Monday I should be replacing the ball joints though....no wouldn't get here in time so doesn't matter. If it leaks......i'll replace :thumbup: otherwise i'm not gonna worry about it. already spent enough money on this. 

After this i have to tear interior out so that i can patch a hole


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