# Going from a B12 4 speed to a B11 5 speed



## WhiteFox (Sep 4, 2002)

There seems to be only 2 differences; one being the mount. 
Amazingly, both transmissions are the same length :crazy: The 4 speed also has unused bolt holes that happen to be in the same location as the B11 5 speed.. so you can use either a B11 or a B12 mount on it. But anyways..
I can't get ahold of the B11 mount easily enough so I'm going to modify my old one. :balls: Time to break out the welder and have some fun..

The second difference is the yoke that the shifter linkage connects to. It's off about 10mm in every direction, and isn't offset from the center like the 4 speed.
Time to hammer out the pin and switch 'em..










I'll keep y'all updated if I run accross any more issues. It doesn't look like much of a challenge, all too simple with the right parts on hand.


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## WhiteFox (Sep 4, 2002)

Okay! To recap; you'll need a B11 front tranny mount, and the yoke from a B12 tranny. That's all it takes to make it a direct drop in.


Easy enough, as long as everything breaks freely that is... (Blowtorch? No... Prybar? No... Dremel... You damn skippy!)

Anywho..

The B11 transmission works like a champ. Once again, many thanks to BlownB310.


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## WhiteFox (Sep 4, 2002)

Here is a picture of my modified B12 bracket.. Not a very pretty sight :banhump:









That's a piece of 1/8" thick steel. I cut a place for it to sit in on the mount and welded it in place. I spraypainted it to keep the rust down.

Here's a pic of it unpainted, mounted to the B11 tranny.










I know, I make some butt-ugly welds.  It'll hold for now..


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## blownb310 (Jun 10, 2002)

Whitefox,

Thanks for posting your swap experience [with pics to]!  

I'm glad it was as simple as I thought it would be. As you know from my PM, I did find the original B11 mount. Maybe it will make the job even easier! 

So, how does it feel to be the only B12 driver around to have 4.17 gears and an lsd? :thumbup: 

I've got two more stock B11 tranny's here. $50 plus shipping [each] to whoever wants one.


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## Crazy-Mart (Jul 14, 2002)

he got LSD ?? ... OMG lucky guy !! ... nice stuff you made there !! wath clutch did you use ??


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## WhiteFox (Sep 4, 2002)

The 4.17 gearing is absolutely perfect on this gearbox--Nissan really should have made these for every sentra! It pulls like a truck in 1st and I can still pull hills in 5th. From my calculations, 5th should be good up to about 135 :thumbup: I can't comment on the LSD yet, haven't had enough seat time to see what it'll handle  

I'm using a brand new 'stock' B12 190 mm Exedy clutch and pressure plate.


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## 87SENTRASE (May 16, 2002)

B11 had smaller clutch assembly than B12. Just slightly.


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## Crazy-Mart (Jul 14, 2002)

both are 180mm ... the n12 had 200mm


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## blownb310 (Jun 10, 2002)

Crazy-Mart said:


> both are 180mm ... the n12 had 200mm


Hello Martin,

I just wanted to clear up a small error. The B11's did use a 180mm disc, but the B12's all used a 190mm disc. The only exceptions are the N12 turbo and the B12 4WD's, which both use a 200mm clutch assembly.

So Whitefox, you must have used a 190mm B12 E16i flywheel on your B11 right?

Mike


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## WhiteFox (Sep 4, 2002)

Wow haven't visited here in a while...

I'm only assuming I had the 190 clutch as I ordered one for the B12's. Now that you mention it, I wonder if that could have something to do with the odd 'hissing' sound I'm getting. Hope it's not grinding the tranny case or something. Been doing it since I got it on the car. It comes and goes and I can make it happen if I push my shifter upwards in 3rd & 5th.. It took me a long time to track that sound down and make it repeatable.

I used to think it was an intake leak of some kind, since it sounded like one. The car feels like it bogs when it *isn't* making the sound, however. Very unusual. Any idea?


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## blownb310 (Jun 10, 2002)

Man you got me. I was thinkg exhaust leak when I first read your description.  

I seriously doubt the flywheel is rubbing in the trans case. Perhaps the throwout bearing is starting to go though. 

Good to hear from you Whitefox!

Mike


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## WhiteFox (Sep 4, 2002)

I hope it's not the throwout bearing, since it was newly installed like the clutch + pressure plate. Being that it is new and also has made that sound since it was installed, I wouldn't suspect it.

Right now the tranny is the least of my worries.. my drivers' side tie rod end is out of whack & my front struts are blown. Another interesting thing I've had to deal with was my rocker rod (whatever the rockers attatch to is called) bolts worked themselves out and lifted it up to where they were knocking my valve cover! It still ran... these things are hard to kill


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## blownb310 (Jun 10, 2002)

WhiteFox said:


> I hope it's not the throwout bearing, since it was newly installed like the clutch + pressure plate. Being that it is new and also has made that sound since it was installed, I wouldn't suspect it.


I hope not too, but keep in mind that the 190mm throwout bearing is different than the B11 180mm bearing. As long as the bearing matches the clutch your good.


WhiteFox said:


> Another interesting thing I've had to deal with was my rocker rod (whatever the rockers attatch to is called) bolts worked themselves out and lifted it up to where they were knocking my valve cover! It still ran... these things are hard to kill


I've seen that happen before and had to re-thread a few rocker shaft mounting holes in the head with a heli-coil.


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