B15/P11 tranny- why it's better than B13/B14 - SR20 Forum
Reply
 
Thread Tools
post #1 of 146 (permalink) Old 01-16-2005, 07:39 PM Thread Starter
Grandma's gonna get ya!
 
coalitionSE-L's Avatar
 
Join Date: Sep 2003
Location: Rock-Vegas, FL
Posts: 1,871
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 6 reviews
(Thread Starter)
B15/P11 tranny- why it's better than B13/B14

Well, I started pulling my B15 tranny apart today to install my friction type LSD and thought I'd share with all of you a little bit of what I found. We all know that B15 trannys hold up to high HP way better than B13/B14 trannys and I've frequently seen many folks wondering what exactly is responsible for this. Unfortunately, there really hasn't been any definitive answer. Thanks to a friend of mine who has many torn apart B13 trannys, I was able to compare and spot some big changes in the B15 tranny. Hopefully what I have found will shed some light on the major differences. I am assuming that the P11 tranny is identical but I don't have one to compare with here.

What we already know:
There is some seperation of the input and main shafts under WOT that occurs in B13/B14 trannys. This puts a great deal of stress on the ends of the gear teeth (at its worst in 3rd) leading to shearing in high HP scenarios. The B15 tranny does not seem to have this problem and thus holds up much better to high HP applications.

But why?:
Obviously the B15 case is significantly different than B13/B14 cases. An addition that was made with the introduction of the B15 tranny is pictured below.



The two seemingly pointless 14mm bolts pictured actually serve a very important purpose and that is reinforcement. Inside the sleeves that they screw into is a small spring that holds pressure on a check ball (2 springs and 2 check balls total). The check balls contact the two shifter rods that 'ride' the main shaft and essentially hold tension on them when in place. The shifter rods are notched where the check balls contact them and you cannot even remove the case without removing those two bolts first. This is quite a nice improvement over the B13/B14 design where the shifter rods are loose at best. In addition to this, the shifter rod that 'rides' the input shaft sports a much beefier fork and sits with much more stability over the B13/B14 counterpart. Support, stability and reinforcement are obviously greatly improved.

As far as the internals go, everything is different, including the diff. IMHO, it seems like the gear stacks are beefier on the B15 tranny (see pic below). Sorry that I have no comparison pics with a B13 or B14 tranny.



Probably the biggest difference that sets the B15 tranny apart though is the positioning of the reverse idler gear. To get to the gear, you must take off the small cover pictured below, and remove its retainer pin (also pictured below). This gear is actually held into the tranny case itself (by the retainer pin) and meshes with the input shaft. It basically forces the input shaft to stay completely meshed with the main shaft, yet another reason why there is virtually no play in these trannys.


Reverse idler gear cover


Removing the snap ring to take out the retainer pin.


Threading a small bolt from the cover into the retainer pin to lift it out.


The actual retainer pin removed.


After the pin is removed, the reverse idler gear pulls right out of the case.

So to highlight how the input and main shafts stay meshed in the B15 tranny, I give you the following synopsis:

Input shaft: Supported on one end by the input shaft bearing and on the other end by the reverse idler gear and a better design rear bearing, thereby preventing play under WOT.

Main shaft: Supported on one end by the diff final drive gear and on the other by the spring-loaded check balls as well as the bearing race, thereby preventing play under WOT.



Hope this sheds some light on some big differences between the two types of trannys......

1999 SE-L SR20DET-- Sold!
1997 Maxima-- The bone-stock family machine!
2004 Xterra-- The wife's ride!

With over 250 pictures showing my turbo SE-L project.


Last edited by coalitionSE-L; 03-11-2005 at 01:03 AM.
coalitionSE-L is offline  
Sponsored Links
Advertisement
 
post #2 of 146 (permalink) Old 01-16-2005, 07:44 PM
PLAY MY HEAD, MONKEY!
 
daveracer's Avatar
 
Join Date: May 2003
Location: Shrewsbury, MA
Posts: 9,943
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 93 reviews
Wow pretty cool. B15 tranny here i cooooome!

.
daveracer is offline  
post #3 of 146 (permalink) Old 01-16-2005, 10:26 PM Thread Starter
Grandma's gonna get ya!
 
coalitionSE-L's Avatar
 
Join Date: Sep 2003
Location: Rock-Vegas, FL
Posts: 1,871
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 6 reviews
(Thread Starter)
In my initial post, I forgot to mention the biggest difference that sets the B15 tranny apart. I have added it to the original post.

1999 SE-L SR20DET-- Sold!
1997 Maxima-- The bone-stock family machine!
2004 Xterra-- The wife's ride!

With over 250 pictures showing my turbo SE-L project.

coalitionSE-L is offline  
 
post #4 of 146 (permalink) Old 01-16-2005, 10:49 PM
Technician @ Toyota
 
scortch99th's Avatar
 
Join Date: Sep 2003
Location: Queens, New York
Posts: 2,852
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 45 reviews
well whos got a clean b15 tranny for sale. im up for one of those.

91 classic SE-R (sold)
94 classic LE (falling apart beater)
91 240sx(rps13) (sold)
95 P10 Primera (current daily)
COMPRESSED CLIQ
Quote:
Originally Posted by STRATTON
freddie your a SICK man.

stratton.
Quote:
Originally Posted by chriscar
Maximum horsepower is dictated by your wallet.

C
scortch99th is offline  
post #5 of 146 (permalink) Old 01-16-2005, 11:09 PM
Rotten Egg
 
Join Date: May 2004
Location: Cincinnati, Ohio
Posts: 599
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 8 reviews
so does anyone know if the p11 tranny and b15 trannys are the same??? and do you have to do the same modifications to the b15 tranny as you do the p11 tranny thats explained in the techinical library?

edit: shit nevermind i just read that thread again and answered my own question... sorry that..

matt

93 Electric Blue NX2000
1gDSMer is offline  
post #6 of 146 (permalink) Old 01-17-2005, 02:15 AM
Hostile Aberration
 
Shawn B's Avatar
 
Join Date: Sep 2004
Location: Louisiana
Posts: 4,820
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 10 reviews
Thank you coalitions-el, even I could understand your write-up and pics . I fixed my B-13 tranny just last year, but next time that biatch starts acting up, it B-15 tranny here I come!

2004 Tahoe, stock and fully loaded.
'93 Classic - Original Owner, "OEM Plus" modifications

* The best offense is a good psychosis. *
Shawn B is offline  
post #7 of 146 (permalink) Old 01-17-2005, 03:50 AM
 
Join Date: Sep 2004
Posts: 2,890
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 3 reviews
I think we need a b15 LSD group buy :P
liupj is offline  
post #8 of 146 (permalink) Old 01-17-2005, 04:44 AM
Rotten Egg
 
Join Date: May 2004
Location: Cincinnati, Ohio
Posts: 599
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 8 reviews
wait a few months on that group buy how much do b15 trans' go for these days?
matt

93 Electric Blue NX2000
1gDSMer is offline  
post #9 of 146 (permalink) Old 01-17-2005, 10:06 AM Thread Starter
Grandma's gonna get ya!
 
coalitionSE-L's Avatar
 
Join Date: Sep 2003
Location: Rock-Vegas, FL
Posts: 1,871
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 6 reviews
(Thread Starter)
Quote:
Originally Posted by Shawn B
Thank you coalitions-el, even I could understand your write-up and pics . I fixed my B-13 tranny just last year, but next time that biatch starts acting up, it B-15 tranny here I come!
No problem, even I was wondering why the B15 tranny was so much better than the B13/B14......until yesterday. I figured I'd try to do a good write-up since I've seen so many other people who wondered as well.

1999 SE-L SR20DET-- Sold!
1997 Maxima-- The bone-stock family machine!
2004 Xterra-- The wife's ride!

With over 250 pictures showing my turbo SE-L project.

coalitionSE-L is offline  
post #10 of 146 (permalink) Old 01-17-2005, 10:40 AM
aka Mr Ryte on G20.net
 
Join Date: Dec 2001
Location: San Antonio, TX
Posts: 1,478
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Thanks for the writeup, bro. Very informative.
If i ever blow up my P10, I'll know what to look for.

Vehicle:1995 Dark Green Infiniti G20
Real name:Howard Wright
Current mods:91 intake cam at 19* degrees, TopSpeed header, M3-style rear wing, P11 rims, *Recaro LS-L seats*
I.C.E.:Pioneer DEH-P6800MP CD/MP3 HU, Audiobahn AS65Q 6.5" components in front & back....HELLZ YEAH!!!!
"THOU SHALT NOT MOD THAT WHICH THY CANNOT MAINTAIN" -thus speaketh Mr. Ryte
howard_w13 is offline  
post #11 of 146 (permalink) Old 01-17-2005, 11:05 AM
B15 Smack Junky
 
Join Date: Mar 2002
Location: Ledyard, CT @ redline!
Posts: 1,080
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
I'm So ganking those pics man

2001 SE - Baby
1991 SE-R - Brother Owns this.
1997 B4000 - Sister Soon to own this.
2011 Toyota 4runner

www.b15sentra.net
SR20DEe is offline  
post #12 of 146 (permalink) Old 01-17-2005, 11:11 AM
B15 Smack Junky
 
Join Date: Mar 2002
Location: Ledyard, CT @ redline!
Posts: 1,080
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Quote:
Originally Posted by coalitionSE-L


As far as the internals go, everything is different except for the diff. IMHO, it seems like the gear stacks are beefier on the B15 tranny (see pic below). Sorry that I have no comparison pics with a B13 or B14 tranny.
http://www.se-r-list.org/fifth.gear.phtml

just thought it would help a little bit.. although not by much..


2001 SE - Baby
1991 SE-R - Brother Owns this.
1997 B4000 - Sister Soon to own this.
2011 Toyota 4runner

www.b15sentra.net
SR20DEe is offline  
post #13 of 146 (permalink) Old 01-17-2005, 11:14 AM
B15 Smack Junky
 
Join Date: Mar 2002
Location: Ledyard, CT @ redline!
Posts: 1,080
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
I have noticed before on other (simple case comparo's that the b15 tranny looks alot larger.. any way to take some measurements of the FINAL and gear set? also can you measure input to output shaft spacing? I'm simply curios :p

2001 SE - Baby
1991 SE-R - Brother Owns this.
1997 B4000 - Sister Soon to own this.
2011 Toyota 4runner

www.b15sentra.net
SR20DEe is offline  
post #14 of 146 (permalink) Old 01-19-2005, 01:04 AM Thread Starter
Grandma's gonna get ya!
 
coalitionSE-L's Avatar
 
Join Date: Sep 2003
Location: Rock-Vegas, FL
Posts: 1,871
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 6 reviews
(Thread Starter)
Quote:
Originally Posted by SR20DEe
I have noticed before on other (simple case comparo's that the b15 tranny looks alot larger.. any way to take some measurements of the FINAL and gear set? also can you measure input to output shaft spacing? I'm simply curios :p
I won't be able to get back out and work on the tranny until this weekend, but I am definitely going to. I will most likely have it put back together too, but I can try to take some measurements for you while it's still apart. Can you be more specific as to what measurements you want taken? I understand that you want me to measure the final drive gear but what else specifically are you looking for?

1999 SE-L SR20DET-- Sold!
1997 Maxima-- The bone-stock family machine!
2004 Xterra-- The wife's ride!

With over 250 pictures showing my turbo SE-L project.

coalitionSE-L is offline  
post #15 of 146 (permalink) Old 01-19-2005, 07:33 AM
B15 Smack Junky
 
Join Date: Mar 2002
Location: Ledyard, CT @ redline!
Posts: 1,080
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
with your caliper(or what ever measure ment tool) I want you to measure the Direct distance in MM from the centers of each shaft(input and output)
I'd Kill for the Sizes of the each of the input and output gears.. but it probably would be worthless

ive bookmarked this thread For whenever I feel Competent enough to Tear down my Tranny (100,000 miles from now Or whenever i blow the 4th gear synchro away from abuse)

2001 SE - Baby
1991 SE-R - Brother Owns this.
1997 B4000 - Sister Soon to own this.
2011 Toyota 4runner

www.b15sentra.net
SR20DEe is offline  
post #16 of 146 (permalink) Old 01-19-2005, 09:07 AM
 
Join Date: Sep 2004
Posts: 111
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 1 reviews
are B15 and P11 trannys the same?
stealth_b13 is offline  
post #17 of 146 (permalink) Old 01-19-2005, 10:34 AM
B15 Smack Junky
 
Join Date: Mar 2002
Location: Ledyard, CT @ redline!
Posts: 1,080
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
b15 transmission Pinion Gear has less teeth easily resolvable. during the swap I would assume.


In other words.. sorta.. b15 transmission is designed to be very SHORT

OH.. and there is an extra tooth on the 5th gear of the G20

2001 SE - Baby
1991 SE-R - Brother Owns this.
1997 B4000 - Sister Soon to own this.
2011 Toyota 4runner

www.b15sentra.net

Last edited by SR20DEe; 01-19-2005 at 10:53 AM.
SR20DEe is offline  
post #18 of 146 (permalink) Old 01-19-2005, 10:39 AM
SE-R Nut
 
Join Date: Oct 2004
Location: North Carolina
Posts: 606
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Quote:
Originally Posted by stealth_b13
are B15 and P11 trannys the same?
I am pretty sure the b15 and p11 trannys are the same. They look just a like. They do have different gear ratios though.
NissanSpeed01 is offline  
post #19 of 146 (permalink) Old 01-19-2005, 11:59 AM
SE-R Master
 
eric96ser's Avatar
 
Join Date: Apr 2000
Location: Nashville TN
Posts: 9,409
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 29 reviews
From looking at this pic:


and this one:


It looks like the gears are moved around on the shafts. Normally 5th gear is on top of the input shaft, but now it looks like its in the middle. In the B15 transmission, does the fork move between 2 gears, or one?

1996 200SX SE-R VE powered
2004 Subaru Forester turbo
2006 Mitsubishi Evolution IX

The community is here.
eric96ser is offline  
post #20 of 146 (permalink) Old 01-19-2005, 06:39 PM
Rob
SE-R Geek
 
Join Date: Sep 2001
Location: Long Island, NY
Posts: 2,887
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Feedback Score: 6 reviews
here are better pics. this is my new tranny since the 5th gear died in my ser at 44K
https://www.sr20forum.com/showthread.php?t=59871

2K2 SE 6spd Maxima
Rob is offline  
Sponsored Links
Advertisement
 
Reply

  SR20 Forum > What's New > Technical Information Library > Driveline & Transmission


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome